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Supplemental Digital Content is Available in the Text. Background: An effective vaccine is required to end the HIV pandemic. We evaluated the safety and immunogenicity of a DNA (DNA-HIV-PT123) vaccine with low- or high-dose bivalent (TV1.C and 1086.C glycoprotein 120) subtype C envelope protein combinations, adjuvanted with MF59 or AS01B. Methods: HIV Vaccine Trials Network (HVTN)108 was a randomized, placebo-controlled, double-blind, phase 1/2a trial conducted in the United States and South Africa. HIV-negative adults were randomly assigned to 1 of 7 intervention arms or placebo to assess DNA prime with DNA/protein/adjuvant boosts, DNA/protein/adjuvant co-administration, and low-dose protein/adjuvant regimens. HVTN111 trial participants who received an identical regimen were also included. Outcomes included safety and immunogenicity 2 weeks and 6 months after final vaccination. Results: From June 2016 to July 2018, 400 participants were enrolled (N = 334 HVTN108, N = 66 HVTN111); 370 received vaccine and 30 received placebo. There were 48 grade 3 and 3 grade 4 reactogenicity events among 39/400 (9.8%) participants, and 32 mild/moderate-related adverse events in 23/400 (5.8%) participants. All intervention groups demonstrated high IgG response rates (>89%) and high magnitudes to HIV-1 Env gp120 and gp140 proteins; response rates for AS01B-adjuvanted groups approached 100%. V1V2 IgG magnitude, Fc-mediated functions, IgG3 Env response rates, and CD4+ T-cell response magnitudes and rates were higher in the AS01B-adjuvanted groups. The AS01B-adjuvanted low-dose protein elicited greater IgG responses than the higher protein dose. Conclusions: The vaccine regimens were generally well tolerated. Co-administration of DNA with AS01B-adjuvanted bivalent Env gp120 elicited the strongest humoral responses; AS01B-adjuvanted regimens elicited stronger CD4+ T-cell responses, justifying further evaluation. ClinicalTrials.gov registration: NCT02915016, registered 26 September 2016. [ABSTRACT FROM AUTHOR]

MF59 and AS03 are squalene emulsion-based vaccine adjuvants with similar compositions and droplet sizes. Despite their broad use in licensed influenza vaccines, few studies compared their adjuvant effects and action mechanisms side by side. Considering the majority of adjuvants act on dendritic cells (DCs) to achieve their adjuvant effects, this study compared MF59 and AS03-like adjuvants (AddaVax and AddaS03, respectively) to enhance antigen uptake, DC maturation, ovalbumin (OVA) and seasonal influenza vaccine-induced immune responses. Considering MF59 was reported to activate MyD88 to mediate its adjuvant effects, this study also investigated whether the above-explored adjuvant effects of AddaVax and AddaS03 depended on MyD88. We found AddaVax more potently enhanced antigen uptake at the local injection site, while AddaS03 more potently enhanced antigen uptake in the draining lymph nodes. AddaS03 but not AddaVax stimulated DC maturation. Adjuvant-enhanced antigen uptake was MyD88 independent, while AddaS03-induced DC maturation was MyD88 dependent. AddaVax and AddaS03 similarly enhanced OVA-induced IgG and subtype IgG1 antibody responses as well as influenza vaccine-induced hemagglutination inhibition antibody titers, whileAddaS03 more potently enhanced OVA-specific IgG2c antibody responses. Both adjuvants depended on MyD88 to enhance vaccine-induced antibody responses, while AddaVax depended more on MyD88 to achieve its adjuvant effects. Our study reveals similarities and differences of the two squalene emulsion-based vaccine adjuvants, contributing to our improved understanding of their action mechanisms. [ABSTRACT FROM AUTHOR]

Infection with influenza A virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) poses a significant risk to human life, health, and the global economy. Vaccination is one of the most effective strategies in the fight against infectious viruses. In this study, we, for the first time, have evaluated the immunogenicity and protective effect of an influenza/SARS‐CoV‐2 Omicron subunit combined vaccine adjuvanted with MF59 and administered to BALB/c mice. Results showed that the combined vaccine induced high levels of IgG, IgG1, and IgG2a antibodies, as well as influenza A H1N1/California/2009 virus‐specific hemagglutination‐inhibiting antibodies in BALB/c mice. Moreover, this subunit combined vaccine induced high titers of neutralization antibodies against SARS‐CoV‐2 Omicron sublineage BA.5 pseudovirus and effectively reduced the viral load of authentic SARS‐CoV‐2 Omicron sublineage BA.5.2 in the cell culture supernatants. These results suggested that this subunit combined vaccine achieved protective effect against both H1N1 A/California/07/2009 strain and SARS‐CoV‐2 Omicron BA.5.2 variant. It is therefore expected that this study will establish the scientific foundation for the next‐step development of combined vaccines against other strains or variants of IAV and SARS‐CoV‐2. [ABSTRACT FROM AUTHOR]

MF59 and AS03 are squalene emulsion-based vaccine adjuvants with similar compositions and droplet sizes. Despite their broad use in licensed influenza vaccines, few studies compared their adjuvant effects and action mechanisms side by side. Considering the majority of adjuvants act on dendritic cells (DCs) to achieve their adjuvant effects, this study compared MF59 and AS03-like adjuvants (AddaVax and AddaS03, respectively) to enhance antigen uptake, DC maturation, ovalbumin (OVA) and seasonal influenza vaccine-induced immune responses. Considering MF59 was reported to activate MyD88 to mediate its adjuvant effects, this study also investigated whether the above-explored adjuvant effects of AddaVax and AddaS03 depended on MyD88. We found AddaVax more potently enhanced antigen uptake at the local injection site, while AddaS03 more potently enhanced antigen uptake in the draining lymph nodes. AddaS03 but not AddaVax stimulated DC maturation. Adjuvant-enhanced antigen uptake was MyD88 independent, while AddaS03-induced DC maturation was MyD88 dependent. AddaVax and AddaS03 similarly enhanced OVA-induced IgG and subtype IgG1 antibody responses as well as influenza vaccine-induced hemagglutination inhibition antibody titers, whileAddaS03 more potently enhanced OVA-specific IgG2c antibody responses. Both adjuvants depended on MyD88 to enhance vaccine-induced antibody responses, while AddaVax depended more on MyD88 to achieve its adjuvant effects. Our study reveals similarities and differences of the two squalene emulsion-based vaccine adjuvants, contributing to our improved understanding of their action mechanisms.

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The most effective means of preventing seasonal influenza is through vaccination. In this systematic review, we investigated the efficacy, effectiveness and safety of MF59® adjuvanted trivalent and quadrivalent influenza vaccines to prevent laboratory‐confirmed influenza. A systematic literature search was conducted in electronic databases and grey literature sources up to 7 February 2020. Randomised controlled trials and non‐randomised studies of interventions (NRSIs) were eligible for inclusion. The search returned 28,846 records, of which 48 studies on MF59® adjuvanted vaccines met our inclusion criteria. No efficacy trials were identified. In terms of vaccine effectiveness (VE), MF59® adjuvanted trivalent influenza vaccines were effective in preventing laboratory‐confirmed influenza in older adults (aged ≥65 years) compared with no vaccination (VE = 45%, 95% confidence interval (CI) 23%–61%, 5 NRSIs across 3 influenza seasons). By subtype, significant effect was found for influenza A(H1N1) (VE = 61%, 95% CI 44%–73%) and B (VE = 29%, 95% CI 5%–46%), but not for A(H3N2). In terms of relative VE, there was no significant difference comparing MF59® adjuvanted trivalent vaccines with either non‐adjuvanted trivalent or quadrivalent vaccines. Compared with traditional trivalent influenza vaccines, MF59® adjuvanted trivalent influenza vaccines were associated with a greater number of local adverse events (RR = 1.90, 95% CI 1.50–2.39) and systemic reactions (RR = 1.18, 95% CI 1.02–1.38). In conclusion, MF59® adjuvanted trivalent influenza vaccines were found to be more effective than 'no vaccination'. Based on limited data, there was no significant difference comparing the effectiveness of MF59® adjuvanted vaccines with their non‐adjuvanted counterparts. [ABSTRACT FROM AUTHOR]

Foot and mouth disease (FMD) and enterotoxemia are important diseases of hoofed animals. Vaccination against livestock pathogens, especially these two diseases, plays a key role in the prevention and control of these diseases. The use of combined vaccines with the aim of creating a better immune response and producing cheaper vaccines is a great contribution to Vaccine industry. This research aimed to compare the immunogenicity of FMD (O) and Clostridium perfringens type B toxoid along with adjuvant (MF59) and Montanide (ISA70) to create the best immunogenicity. To investigate the immune responses of vaccines, it was injected into an animal model, and the antibody titer was measured by enzyme-linked immunosorbent assay (ELISA) test and VN antibody titer. The results showed that the formulation with MF59 adjuvant brought more stable immunogenicity against FMD and Clostridium perfringens type B, and the length of the immunogenicity period also increased significantly. Therefore, the combined vaccine (Clostridium perfringens + FMD) could play a major role invaccine industry as an alternative vaccine against Clostridium perfringens and FMD in livestock. [ABSTRACT FROM AUTHOR]

Objective(s): HBsAg vaccine is unable to induce Th1 immune responses. Here, immune responses and long-lived IgG responses of HBsAg-Alum, HBsAg-MF59, as well as HBsAg-MF59 were compared when formulated with PPD. Materials and Methods: BALB/c mice were injected with the vaccines subcutaneously three times with a two-week interval. Then, specific IgG, long-lived IgG responses up to 220 days, and also IgG1 and IgG2a isotypes were assessed using ELISA. Furthermore, IFN-γ and IL-4 were assessed on spleen cell culture supernatant by ELISA. Results: IFN-γ cytokine response between MF59- and Alum-adjuvanted vaccines did not show a significant difference. HBsAg-Alum vaccine revealed an increase in IL-4 cytokine, as compared with those immunized with HBsAg-MF59 at borderline (P=0.0553). In addition, HBsAg-MF59+PPD 10 µg showed a significant decrease in IL-4 and IFN-γ cytokines, as compared with HBsAg-MF59. Furthermore, the HBsAg-MF59+PPD10 µg group showed a significant increase in the IL-2/IL-4 ratio, as compared with HBsAg-MF59 (P=0.0339). Specific IgG antibody showed a significant increase in HBsAg-MF59, as compared with HBsAg-Alum. Furthermore, HBsAg-MF59 plus PPD showed a significant increase in IgG responses, as compared with HBsAg-MF59 and HBsAg-Alum groups. Long-lived IgG responses up to 220 days after the final shot showed a significant increase in HBsAgMF59 versus HBsAg-Alum group and PPD in the HBsAg-MF59 vaccine formulation, resulting in a significant increase in IgG responses versus HBsAg-MF59 group. In addition, PPD in the HBsAg-MF59 vaccine formulation suppressed IgG1 response versus HBsAg-Alum. However, HBsAg-MF59 showed a significant increase in IgG2α versus the HBsAg-Alum group (P=0.0190). Immunization with HBsAg-MF59+PPD (10 µg) showed a significant increase versus the HBsAg-MF59 group (P=0.0040). Results from the IgG2a/IgG1 ratio in HBsAg-MF59+PPD1µg and HBsAg-MF59+PPD10 µg groups showed a significant increase as compared with HBsAg-MF59 groups (P

Objective(s): Here, immune responses and long-lived IgG responses of HBsAg-Alum, HBsAg-MF59, as well as HBsAg-MF59 were compared when formulated with PPD. Materials and Methods: BALB/c mice were vaccinated subcutaneously three times with a twoweek -interval. Then, specific IgG, long-lived IgG responses up to 220 days, and IgG1/ IgG2a isotypes, and IFN-γ and IL-4 on spleen cell culture supernatant were assessed using ELISA. Results: IFN-γ cytokine response between MF59- and Alum-adjuvanted vaccines did not show a significant difference. HBsAg-Alum revealed an increase in IL-4 cytokine versus HBsAg-MF59 at borderline (P=0.0553). In addition, HBsAg-MF59+PPD 10µg showed a significant decrease in IL-4 and IFN-γ cytokines versus HBsAg-MF59. Furthermore, HBsAg-MF59+PPD10 µg showed a significant increase in the IL-2/IL-4 ratio versus HBsAg-MF59 (P=0.0339). Specific IgG antibody showed a significant increase in HBsAg-MF59, as compared with HBsAg-Alum. Furthermore, HBsAg-MF59 plus PPD showed a significant increase in IgG responses versus HBsAg-MF59 and HBsAg-Alum groups. Long-lived IgG responses showed a significant increase in HBsAgMF59 versus HBsAg-Alum group and PPD in the HBsAg-MF59 vaccine formulation, resulting in a significant increase in IgG responses versus HBsAg-MF59 group. In addition, HBsAg-MF59 plus PPD suppressed IgG1 response versus HBsAg-Alum. However, HBsAg-MF59 showed a significant increase in IgG2α versus the HBsAgAlum group (P=0.0190). Immunization with HBsAg-MF59+PPD (10 µg) showed a significant increase versus the HBsAg-MF59 group (P=0.0040). IgG2a/IgG1 ratio in HBsAg-MF59+PPD1µg and HBsAgMF59+PPD10 µg groups showed a significant increase versus HBsAg-MF59 groups (P<0.0345). Conclusion: PPD leads to a more potent long-lived IgG responses in the HBsAg vaccine, highlighting its potential as a component of a complex adjuvant. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) and Avian influenza (AI) are the major problems and the most economically important viral diseases in the poultry industry; therefore, vaccination against these diseases is considered one of the most effective ways of prevention. Extensive studies have been conducted to improve the performance of vaccines, and one of the major achievements of these studies is the preparation of adjuvants as stimulants of the immune system and one of the most important compounds in killed vaccines. An immunogenicity comparison of three adjuvants including, ISA70VG, Nano-Aluminum Hydroxide (Nano-Alum), and MF59 alone or with Nano-Selenium (Nano-Se), was performed using bivalent Newcastle plus Avian Influenza (ND+AI) killed vaccine. In this study, 105 specific-pathogen-free chicks (Ross-308) were divided into 7 treatments, including T1 (control group), T2 (ISA70VG), T3 (ISA70VG plus Nano-Se), T4 (Nano-Alum Hydroxide), T5 (Nano-Alum+Nano-Se), T6 (MF59), and T7 (MF59+Nano-Se). The vaccine was injected subcutaneously on day 21 in the back of the neck area. The blood samples were taken on days 14, 21, 28, 35, 42, and 49 post-vaccination. Serums of the samples were titrated by the haemagglutination inhibition (HI) test against Newcastle and Avian influenza. Based on the results, the highest HI test titers were observed for the T2 and T3 treatments, while the T6 and T7 treatments had the lowest titers. Moreover, regardless of the type of the adjuvants, adding Nano-Se increased the antibody titer in the vaccinated groups. In conclusion, a combination of the ISA70VG adjuvant and Nano-Se induced excellent antibody titers using bivalent ND+AI killed vaccine.

Our previous study found that CpG oligodeoxynucleotides 1826 (CpG 1826), combined with mucin 1 (MUC1)-maltose-binding protein (MBP) (M-M), had certain antitumor activity. However, this combination is less than ideal for tumor suppression (tumors vary in size and vary widely among individuals), with a drawback being that CpG 1826 is unstable. To solve these problems, here, we evaluate MF59/CpG 1826 as a compound adjuvant with M-M vaccine on immune response, tumor suppression and survival. The results showed that MF59 could promote the CpG 1826/M-M vaccine-induced tumor growth inhibition and a Th1-prone cellular immune response, as well as reduce the individual differences of tumor growth and prolonged prophylactic and therapeutic mouse survival. Further research showed that MF59 promotes the maturation of DCs stimulated by CpG1826/M-M, resulting in Th1 polarization. The possible mechanism is speculated to be that MF59 could significantly prolong the retention time of CpG 1826, or the combination of CpG 1826 and M-M, as well as downregulate IL-6/STAT3 involved in MF59 combined CpG 1826-induced dendritic cell maturation. This study clarifies the utility of MF59/CpG 1826 as a vaccine compound adjuvant, laying the theoretical basis for the development of a novel M-M vaccine. [ABSTRACT FROM AUTHOR]

A diversity of vaccines is necessary to reduce the mortality and morbidity of SARS-CoV-2. Vaccines must be efficacious, easy to manufacture, and stable within the existing cold chain to improve their availability around the world. Recombinant protein subunit vaccines adjuvanted with squalene-based emulsions such as AS03™ and MF59™ have a long and robust history of safe, efficacious use with straightforward production and distribution. Here, subunit vaccines were made with squalene-based emulsions containing novel, synthetic toll-like receptor (TLR) agonists, INI-2002 (TLR4 agonist) and INI-4001 (TLR7/8 agonist), using the recombinant receptor-binding domain (RBD) of SARS-CoV-2 S protein as an antigen. The addition of the TLR4 and TLR7/8 agonists, alone or in combination, maintained the formulation characteristics of squalene-based emulsions, including a sterile filterable droplet size (<220 nm), high homogeneity, and colloidal stability after months of storage at 4, 25, and 40 °C. Furthermore, the addition of the TLR agonists skewed the immune response from Th2 towards Th1 in immunized C57BL/6 mice, resulting in an increased production of IgG2c antibodies and a lower antigen-specific production of IL-5 with a higher production of IFNγ by lymphocytes. As such, incorporating TLR4 and TLR7/8 agonists into emulsions leveraged the desirable formulation and stability characteristics of emulsions and can induce Th1-type humoral and cell-mediated immune responses to combat the continued threat of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

The global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become more serious because of the continuous emergence of variants of concern (VOC), thus calling for the development of broad-spectrum vaccines with greater efficacy. Adjuvants play important roles in enhancing the immunogenicity of protein-based subunit vaccines. In this study, we compared the effect of three adjuvants, including aluminum, nanoparticle manganese and MF59, on the immunogenicity of three protein-based COVID-19 vaccine candidates, including RBD-Fc, RBD and S-trimer. We found that the nanoparticle manganese adjuvant elicited the highest titers of SARS-CoV-2 RBD-specific IgG, IgG1 and IgG2a, as well as neutralizing antibodies against infection by pseudotyped SARS-CoV-2 and its Delta variant. What is more, the nanoparticle manganese adjuvant effectively reduced the viral load of the authentic SARS-CoV-2 and Delta variant in the cell culture supernatants. These results suggest that nanoparticle manganese, known to facilitate cGAS-STING activation, is an optimal adjuvant for protein-based COVID-19 subunit vaccines. [ABSTRACT FROM AUTHOR]

• One way to help achieve community protection against influenza is to vaccinate children. • The best choice of influenza vaccine to achieve both direct and indirect protection is uncertain. • Vaccinating children with aTIV compared to QIV results in similar community RT-PCR confirmed influenza illness. • aTIV can lead to significant protection against influenza A in children. Children play an important role in the transmission of influenza. The best choice of vaccine to achieve both direct and indirect protection is uncertain. The objective of the study was to test whether vaccinating children with MF59 adjuvanted trivalent influenza vaccine (aTIV) can reduce influenza in children and their extended households compared to inactivated quadrivalent vaccine (QIV). We conducted a cluster randomized trial in 42 Hutterite colonies in Alberta and Saskatchewan. Colonies were randomized such that children were assigned in a blinded manner to receive aTIV (0.25 ml of pediatric aTIV for ages 6 months to < 36 months or 0.5 ml for ages ≥ 36 months to 6 years) or 0.5 ml of QIV. Participants included 424 children aged 6 months to 6 years who received the study vaccine and 1246 family cluster members who did not receive the study vaccine. The primary outcome was confirmed influenza A and B infection using a real-time reverse transcriptase polymerase chain reaction (RT-PCR) assay. An intent to treat analysis was used. Data were collected from January 2017 to June 2019. The mean percentage of children who received study vaccine was 62% for aTIV colonies and 74% for QIV colonies. There were 66 (3.4%) with RT-PCR confirmed influenza A and B in the aTIV colonies (children and family clusters) versus 93 (4.4%) in the QIV colonies, hazard ratio (HR) 0.78 (95 %CI 0.36–1.71). Of these, 48 (2.5%) in the aTIV colonies and 76 (3.6%) in the QIV colonies had influenza A, HR 0.69, (95 %CI 0.29–1.66) while 18 (0.9%) and 17 (0.8%) in the aTIV versus QIV colonies respectively had influenza B, HR 1.22, (95 %CI 0.20–7.41). In children who received study vaccine, there were 5 Influenza A infections in the aTIV colonies (1.1%) compared to 30 (5.8%) in the QIV colonies, relative efficacy of 80%, HR 0.20, (95 %CI 0.06–0.66). Adverse events were significantly more common among children who received aTIV. No serious vaccine adverse events were reported. Vaccinating children with aTIV compared to QIV resulted in similar community RT-PCR confirmed influenza illness and led to significant protection against influenza A in children. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) and Avian influenza (AI) are the major problems and the most economically important viral diseases in the poultry industry; therefore, vaccination against these diseases is considered one of the most effective ways of prevention. Extensive studies have been conducted to improve the performance of vaccines, and one of the major achievements of these studies is the preparation of adjuvants as stimulants of the immune system and one of the most important compounds in killed vaccines. An immunogenicity comparison of three adjuvants including, ISA70VG, Nano-Aluminum Hydroxide (Nano-Alum), and MF59 alone or with Nano-Selenium (Nano-Se), was performed using bivalent Newcastle plus Avian Influenza (ND+AI) killed vaccine. In this study, 105 specific-pathogen-free chicks (Ross-308) were divided into 7 treatments, including T1 (control group), T2 (ISA70VG), T3 (ISA70VG plus Nano-Se), T4 (Nano-Alum Hydroxide), T5 (Nano-Alum+Nano-Se), T6 (MF59), and T7 (MF59+Nano-Se). The vaccine was injected subcutaneously on day 21 in the back of the neck area. The blood samples were taken on days 14, 21, 28, 35, 42, and 49 post-vaccination. Serums of the samples were titrated by the haemagglutination inhibition (HI) test against Newcastle and Avian influenza. Based on the results, the highest HI test titers were observed for the T2 and T3 treatments, while the T6 and T7 treatments had the lowest titers. Moreover, regardless of the type of the adjuvants, adding Nano-Se increased the antibody titer in the vaccinated groups. In conclusion, a combination of the ISA70VG adjuvant and Nano-Se induced excellent antibody titers using bivalent ND+AI killed vaccine. [ABSTRACT FROM AUTHOR]

Background & Objective: The influenza virus causes hundreds of deaths in the world. Despite the availability of some authorized vaccines for all age groups and its approved beneficial effects, the influenza is still a major problem for public health. Materials & Methods: In this study, the adjuvant of MF59 was developed by methylglycol-chitosan. The physico-chemical characteristics and immune response stimulation of novel adjuvant were measured in combination with the influenza virus. Results: The new adjuvant was produced with a nano-droplet diameter of 156 and Zeta potential of 29. The pH of adjuvant was not significantly changed for two years. Immunization of mice with developed adjuvant makes more HAI titer than MF59 adjuvant. Conclusion: The favorable characteristics of physico-chemical properties and lack of local side effects of developed adjuvant as well as its strong humoral immunity can introduce it as a novel MF59 adjuvants.

Our previous study found that CpG oligodeoxynucleotides 1826 (CpG 1826), combined with mucin 1 (MUC1)-maltose-binding protein (MBP) (M-M), had certain antitumor activity. However, this combination is less than ideal for tumor suppression (tumors vary in size and vary widely among individuals), with a drawback being that CpG 1826 is unstable. To solve these problems, here, we evaluate MF59/CpG 1826 as a compound adjuvant with M-M vaccine on immune response, tumor suppression and survival. The results showed that MF59 could promote the CpG 1826/M-M vaccine-induced tumor growth inhibition and a Th1-prone cellular immune response, as well as reduce the individual differences of tumor growth and prolonged prophylactic and therapeutic mouse survival. Further research showed that MF59 promotes the maturation of DCs stimulated by CpG1826/M-M, resulting in Th1 polarization. The possible mechanism is speculated to be that MF59 could significantly prolong the retention time of CpG 1826, or the combination of CpG 1826 and M-M, as well as downregulate IL-6/STAT3 involved in MF59 combined CpG 1826-induced dendritic cell maturation. This study clarifies the utility of MF59/CpG 1826 as a vaccine compound adjuvant, laying the theoretical basis for the development of a novel M-M vaccine.

Seasonal influenza is a very common disease. Yearly vaccination of at-risk population groups is a well-recognized cost-effective/cost-saving preventive measure. It is, however, unclear which available alternative has the most favorable economic profile. Some available options are: trivalent (TIV) and quadrivalent (QIV) inactivated vaccines, adjuvanted TIV (aTIV). Because of immunosenescence, aTIV has been specifically developed for elderly. The present study aimed at assessing the available evidence of aTIV use in elderly from the economic perspective. A systematic literature review targeting aTIV economic evaluations in adults aged ≥65 years was performed using Medline via Ovid, Embase, DARE and NHS/EED. Of a total of 3,654 papers screened, 18 studies (13 full papers, 5 conference abstracts) were included. It emerged that compared with both non-vaccination or non-adjuvanted vaccines, aTIV was cost-effective or cost-saving. The vaccinations strategies incorporating aTIV based on age and/or risk profile are associated with the most favorable economic outcomes.

Adjuvants are included in vaccine formulations to enhance the immunogenicity and efficacy of vaccines. MF59® is an oil-in-water emulsion adjuvant and licensed for use in pandemic and seasonal influenza vaccines in many countries. MF59 is safe and well tolerated in humans. MF59-adjuvanted vaccination spares vaccine dose and enhances hemagglutination inhibiting antibodies against homologous and heterologous influenza virus strains. The mechanisms of MF59 involve rapid induction of chemokines, inflammatory cytokines, recruiting multiple immune cells, uric acid and benign apoptosis of certain innate immune cells. The adjuvant effects of MF59 on generating vaccine-specific isotype-switched IgG antibodies, effector CD8 T cells, and protective immunity were retained even in a CD4-deficient condition by inducing effective immune-competent microenvironment with various innate and antigen presenting cells in a mouse model. CD4-independent adjuvant effects of MF59 might contribute to improving the vaccine efficacy in children, the elderly, and immunocompromised patients as well as in healthy adults. Further studies will be needed to broaden the use of MF59 in various vaccine antigens and populations as well as lead to better understanding of the action mechanisms of MF59 adjuvant.

The avian influenza A H7N9 virus has caused severe infection and high mortality in humans. It can be extremely hazardous to the elderly since age might diminish the immune response, and poor immunogenicity of H7 hemagglutinin could diminish the vaccine efficacy in this population. To overcome this issue, adjuvants are used to induce a stronger immune response. In this study, we generated a recombinant H7N9 influenza virus using reverse genetic techniques, consisting of hemagglutinin and neuraminidase genes derived from a human H7N9 virus, with the remaining genes from H1N1 A/Puerto Rico/8/34 (PR8). To evaluate whether the adjuvant can improve immune responses in aged animals, the humoral and cellular immune responses of 18-month-old BALB/c mice to different doses of split avian influenza A H7N9 vaccine with and without the adjuvant MF59 were compared. Our data showed that aged mice immunized with MF59 elicited higher levels of hemagglutination inhibition and microneutralization antibodies and interferon-gamma-specific enzyme-linked immunospot assay (ELISPOT) responses when compared with antigens alone. It is suggested that the split avian influenza A H7N9 vaccine combined with MF59 may significantly improve immune responses to influenza vaccination in elderly humans. [ABSTRACT FROM AUTHOR]

The number of human influenza A (H7N9) infections has escalated since 2013 with high resultant mortality. We conducted a phase II, randomized, partially-blinded trial to evaluate the safety and immunogenicity of an MF59-adjuvanted inactivated, split virion, H7N9 influenza vaccine (H7N9 IIV) administered at various dose levels and schedules in older adults. 479 adults ≥ 65 years of age in stable health were randomized to one of six groups to receive either 3.75, 7.5 or 15 µg of influenza A/Shanghai/02/2013 (H7N9) IIV adjuvanted with MF59 given as a 3-dose series either on days 1, 28 and 168 or on days 1, 57 and 168. Immunogenicity was assessed using both hemagglutination inhibition (HAI) and microneutralization (MN) assays prior to and 28 days following each dose. Safety was assessed through 1 year following the last dose. Subjects in all groups had only modest immune responses, with the HAI GMT < 20 after the second vaccine dose and <29 after the third vaccine dose. HAI titers ≥ 40 were seen in <37% of subjects after the second dose and <49% after the third dose. There were no significant differences seen between the two dose schedules. MN titers followed similar patterns, although the titers were approximately two-fold higher than the HAI titers. Logistic regression modeling demonstrated no statistically significant associations between the immune responses and age, sex or body mass index whereas recent prior receipt of seasonal influenza vaccine significantly reduced the HAI response [OR 0.13 (95% CI 0.05, 0.33); p < 0.001]. Overall, the vaccine was well tolerated. Two mild potentially immune mediated adverse events occurred, lichen planus and guttate psoriasis. MF59-adjuvanted H7N9 IIV was only modestly immunogenic in the older adult population following three doses. There were no significant differences in antibody responses noted among the various antigen doses or the two dose schedules. [ABSTRACT FROM AUTHOR]

The global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become more serious because of the continuous emergence of variants of concern (VOC), thus calling for the development of broad-spectrum vaccines with greater efficacy. Adjuvants play important roles in enhancing the immunogenicity of protein-based subunit vaccines. In this study, we compared the effect of three adjuvants, including aluminum, nanoparticle manganese and MF59, on the immunogenicity of three protein-based COVID-19 vaccine candidates, including RBD-Fc, RBD and S-trimer. We found that the nanoparticle manganese adjuvant elicited the highest titers of SARS-CoV-2 RBD-specific IgG, IgG1 and IgG2a, as well as neutralizing antibodies against infection by pseudotyped SARS-CoV-2 and its Delta variant. What is more, the nanoparticle manganese adjuvant effectively reduced the viral load of the authentic SARS-CoV-2 and Delta variant in the cell culture supernatants. These results suggest that nanoparticle manganese, known to facilitate cGAS-STING activation, is an optimal adjuvant for protein-based COVID-19 subunit vaccines.

The squalene-based oil-in-water emulsion (SE) vaccine adjuvant MF59 has been administered to more than 100 million people in more than 30 countries, in both seasonal and pandemic influenza vaccines. Despite its wide use and efficacy, its mechanisms of action remain unclear. In this study we demonstrate that immunization of mice with MF59 or its mimetic AddaVax (AV) plus soluble antigen results in robust antigen-specific antibody and CD8 T cell responses in lymph nodes and non-lymphoid tissues. Immunization triggered rapid RIPK3-kinase dependent necroptosis in the lymph node which peaked at 6 hr, followed by a sequential wave of apoptosis. Immunization with alum plus antigen did not induce RIPK3-dependent signaling. RIPK3-dependent signaling induced by MF59 or AV was essential for cross-presentation of antigen to CD8 T cells by Batf3-dependent CD8+ DCs. Consistent with this, RIPK3 deficient or Batf3 deficient mice were impaired in their ability to mount adjuvant-enhanced CD8 T cell responses. However, CD8 T cell responses were unaffected in mice deficient in MLKL, a downstream mediator of necroptosis. Surprisingly, antibody responses were unaffected in RIPK3-kinase or Batf3 deficient mice. In contrast, antibody responses were impaired by in vivo administration of the pan-caspase inhibitor Z-VAD-FMK, but normal in caspase-1 deficient mice, suggesting a contribution from apoptotic caspases, in the induction of antibody responses. These results demonstrate that squalene emulsion-based vaccine adjuvants induce antigen-specific CD8 T cell and antibody responses, through RIPK3-dependent and-independent pathways, respectively.

In spite of current influenza vaccines being immunogenic, evolution of the influenza virus can reduce efficacy and so influenza remains a major threat to public health. One approach to improve influenza vaccines is to include adjuvants; substances that boost the immune response. Adjuvants are particularly beneficial for influenza vaccines administered during a pandemic when a rapid response is required or for use in patients with impaired immune responses, such as infants and the elderly. This review outlines the current use of adjuvants in human influenza vaccines, including what they are, why they are used and what is known of their mechanism of action. To date, six adjuvants have been used in licensed human vaccines: Alum, MF59, AS03, AF03, virosomes and heat labile enterotoxin (LT). In general these adjuvants are safe and well tolerated, but there have been some rare adverse events when adjuvanted vaccines are used at a population level that may discourage the inclusion of adjuvants in influenza vaccines, for example the association of LT with Bell's Palsy. Improved understanding about the mechanisms of the immune response to vaccination and infection has led to advances in adjuvant technology and we describe the experimental adjuvants that have been tested in clinical trials for influenza but have not yet progressed to licensure. Adjuvants alone are not sufficient to improve influenza vaccine efficacy because they do not address the underlying problem of mismatches between circulating virus and the vaccine. However, they may contribute to improved efficacy of next-generation influenza vaccines and will most likely play a role in the development of effective universal influenza vaccines, though what that role will be remains to be seen.

The poor immune response elicited by trivalent influenza vaccines (TIVs) in children can be enhanced by the addition of adjuvants. This observer-blind, randomized Phase III trial assessed the immunogenicity and safety of the MF59-adjuvanted trivalent influenza vaccine FLUAD® (aTIV) and a non-adjuvanted TIV, in healthy children (aged 6 to 2, showing that the immunogenicity of aTIV was superior to that of TIV for all 3 strains. Solicited adverse events (AEs) were experienced more frequently with aTIV than TIV by younger children (aged 6 to

Modern cell culture-based technology eliminates vaccine manufactures reliance on embryonated chicken eggs, which may become compromised during an avian influenza pandemic. Four studies (total N = 6230) assessed the immunogenicity and safety of mammalian cell-based, MF59®-adjuvanted, A/H5N1 vaccine (aH5N1c; AUDENZ™) as two doses administered on Days 1 and 22 in children (NCT01776554), adults (NCT01776541; NCT02839330), and older adults (NCT01766921; NCT02839330). Immunogenicity of formulations at 7.5 μg and 3.75 μg antigen per dose were assessed by hemagglutination inhibition and microneutralization assays on Days 1, 22, 43, and 183 or 387. Solicited local and systemic adverse events (AEs) were recorded for 7 days after each vaccination. Unsolicited AEs were collected for 21 days after each vaccination, and serious and other selected AEs were recorded for one year. Antibody responses after two 7.5 μg doses met CBER licensure criteria in all age groups. Overall, an age-related response was evident, with the highest responses observed in children

زمینه و هدف: ویروس آنفلوانزای عامل مرگومیر صدها نفر در دنیا میشود. علیرغم در دسترس بودن واکسن مجاز برای تمام گروههای سنی و علیرغم آثار بهوسیله متیل MF سودمند ثابتشده آن، هنوز ویروس آنفلوانزای بهعنوان یک مشکل عمده برای سلامت عمومی باقیمانده است. در این تحقیق ادجوانت 59 گلیکول کیتوزان ارتقا یافت. مواد و روشها: خصوصیات فیزیکوشیمیایی و میزان تحریک پاسخ ایمنی همورال ادجوانت در ترکیب با ویروس آنفلوانزای اندازهگیری شد. ادجوانت در طول دو سال تغییر محسوس نداشت. ایمونیزاسیون موش با pH . نتایج: ادجوانت جدید با قطر نانوامولوسیون 252 و پتانسیل زتای 61 تولید شد ایجاد کند. MF بیشتری در مقایسه با ادجوانت 59 HAI ادجوانت و ویروس آنفولانزا موجب شد عیار نتیجهگیری: ادجوانت تکاملیافته با ایجاد خواص مطلوب فیزیکوشیمیایی، همچنین القا پاسخ ایمنی همورال قوی و عدم ایجاد عوارض موضعی میتواند جایگزین شود. MF ادجوانت 59 [ABSTRACT FROM AUTHOR]

Background: Several European countries have observed an association between narcolepsy and H1N1 vaccines containing AS03® adjuvant in children/adolescents. In Taiwan, a nationwide campaign starting November 2009 administered H1N1 vaccines without adjuvant or with MF59® adjuvant to 67% of children and 12% of adults.Methods: For those registered in the 2000-2012 National Health Insurance (NHI) databases, we compared age-stratified (0-4, 5-18, 19-59, and ≥60 years) incidence of first referral for a diagnostic MSLT for the pre-pandemic, pandemic/pre-vaccination, and vaccination/post-pandemic period. We also compared the odds of H1N1 vaccination in each chart-ascertained narcolepsy patient, whoever had an onset of excessive daytime sleepiness between April 2009 and December 2012, with 10 population-based controls from the NHI databases on year of birth, sex, and index date, using conditional logistic regressions.Results: Incidence of MSLT referral for narcolepsy was highest and significantly increased in the pandemic/pre-vaccination period in the age group 5-18 (IRR 3.40, 95% confidence intervals (CI) 2.12-5.45) and 19-59 (IRR 2.90, 95% CI 1.62-5.02) years. Among 137 confirmed narcolepsy cases (86 adults and 51 children), the odds ratios (ORs) were 1.67 (95% CI 0.81-3.45) (adults) and 1.22 (95% CI 0.62-2.39) (children) for H1N1 vaccination without adjuvant, and 1.39 (95% CI 0.17-11.48) (adults) and 3.66 (95% CI 0.37-36.02) (children) with MF59® adjuvant.Conclusion: No substantial association between the use of H1N1 vaccines and narcolepsy was identified in Taiwan. Instead, the H1N1 infection itself could have played a role in triggering narcolepsy in children and young adults. [ABSTRACT FROM AUTHOR]

• Highest MF59 dose had greatest influenza vaccine immunogenicity in adults ≥ 65 years. • Increased immunogenicity appeared by Day 8 and persisted to Day 181. • Higher local reactogenicity was observed with the highest dosage of MF59. • Increasing MF59 or HA dosage did not increase unsolicited AEs. To assess the safety and immunogenicity of the MF59®-adjuvanted trivalent influenza vaccine (aTIV; Fluad®) compared with modified aTIV formulations. A total of 196 subjects ≥ 65 years were randomized to receive 7 different formulations of vaccine containing a range of adjuvant and antigen doses by single injection, or divided into two injections at a single time point. The primary study objective was to compare the serologic response of different formulations of aTIV containing increased amounts of adjuvant and antigen 21 days after vaccination. Subjects were followed for immunogenicity and safety for one year. The highest immune response, as measured by hemagglutination inhibition (HI) assay, 3 weeks after vaccination was observed in subjects in Group 6 with GMT 382.2 (95% confidence interval [CI] 237.5 to 615.0), 552.3 (364.8 to 836.1), and 54.1 (36.9 to 79.4) against A/H1N1, A/H3N2, and B respectively. Rates of seroconversion were also generally highest in this treatment group: 75% (95% CI 55.1 to 89.3), 75% (55.1 to 89.3), and 42.9% (24.5 to 62.8), respectively, against A/H1N1, A/H3N2, and B strains. The highest incidence of solicited adverse events (AEs) was reported by subjects who received both the highest dosage of antigen in combination with the highest dosage of adjuvant at the same site: 67.9% and 57.1% in Groups 4 and 6, respectively. The majority of solicited AEs were mild to moderate in severity. The number of unsolicited AEs was similar across the different dosages. In this phase I trial of adults ≥ 65 years of age who received increased adjuvant and antigen dosages relative to the licensed aTIV, increased dosage of MF59 resulted in increased immunogenicity against all 3 components of seasonal influenza vaccine. The increase in immunogenicity was accompanied by an increase in the incidence of local reactogenicity. [ABSTRACT FROM AUTHOR]

• aQIV-associated GMTs and seroconversion rates are noninferior to those of aTIV. • aQIV immunogenicity is superior for B strains not included in aTIV. • aQIV was well tolerated in adults aged ≥65 years. • aQIV is suitable for vaccination of adults aged ≥65 years. Evaluate whether adjuvanted quadrivalent influenza vaccine (aQIV) elicits a noninferior immune response compared with a licensed adjuvanted trivalent influenza vaccine (aTIV-1; Fluad™) and aTIV-2 containing an alternate B strain, examine whether aQIV had immunological superiority for the B strain absent from aTIV comparators, and evaluate reactogenicity and safety among adults ≥65 years. In a multicenter, double-blind, randomized controlled trial, adults ≥65 years were randomized 2:1:1 to vaccination with aQIV (n = 889), aTIV-1 (n = 445), or aTIV-2 (n = 444) during the 2017-2018 influenza season. Immunogenicity was assessed by hemagglutination inhibition (HI) assay conducted on serum samples collected before vaccination and 21 days after vaccination for homologous influenza strains. aQIV met non-inferiority criteria for geometric mean titer ratios (GMT ratios) and seroconversion rate (SCR) differences against aTIV. The upper bounds of the 2-sided 95% confidence interval (CI) for GMT ratios were <1.5 for all 4 strains (A/H1N1 = 1.27, A/H3N2 = 1.09, B-Yamagata = 1.08, B-Victoria = 1.08). The upper bounds of the 95% CI of the SCR differences were <10% for all 4 strains (A/H1N1 = 7.76%, A/H3N2 = 4.96%, B-Yamagata = 3.27%, B-Victoria = 2.55%). aQIV also met superiority criteria (upper bound of 95% CI for GMT ratios <1 and SCR differences <0) for B strain absent from aTIV comparators (B-Yamagata GMT ratio = 0.70, SCR difference = −8.81%; B-Victoria GMT ratio = 0.78, SCR difference = −8.11%). aQIV and aTIV vaccines were immunogenic and well-tolerated. The immunological benefit of aQIV was also demonstrated in age subgroups 65–74 years, 75–84 years, and ≥85 years and in those with high comorbidity risk scores. Reactogenicity profiles were generally comparable. aQIV induces a similar immune response as the licensed aTIV vaccine against homologous influenza strains and has a comparable reactogenicity and safety profile. Superior immunogenicity against the additional B strain was observed, indicating that aQIV could provide a broader protection than aTIV against influenza in older adults (NCT03314662). [ABSTRACT FROM AUTHOR]

Objective(s): In this study, for the first time, MF59 adjuvant was used to develop a cholesteryl ester transfer protein (CETP) vaccine. The efficacy of the vaccine was compared with the efficacy of CETP vaccine formulated with Alum/CpG, the formulation that its immunogenicity has been already demonstrated in rabbit and mice. Materials and Methods: Tetanus toxoid- CETP peptide (TT-CETP) was mixed with Alum/CpG or MF59-like and administered subcutaneously for total five times in rabbit model of atherosclerosis. Anti-TT-CETP specific antibody, CETP activity in sera and mRNA level of cytokine IL-4 and IFN-γ in peripheral mononuclear cells were determined. Therapeutic response was also examined by tracking serum lipoprotein levels and pathologic observation of atherosclerotic lesions at aortic site. Results: More anti-TT-CETP antibody was found in Alum/CpG vaccinated rabbits compared to buffer (P

Influenza poses a huge threat to global public health. Influenza vaccines are the most effective and cost-effective means to control influenza. Current influenza vaccines mainly induce neutralizing antibodies against highly variable globular head of hemagglutinin and lack cross-protection. Vaccine adjuvants have been approved to enhance seasonal influenza vaccine efficacy in the elderly and spare influenza vaccine doses. Clinical studies found that MF59 and AS03-adjuvanted influenza vaccines could induce cross-protective immunity against non-vaccine viral strains. In addition to MF59 and AS03 adjuvants, experimental adjuvants, such as Toll-like receptor agonists, saponin-based adjuvants, cholera toxin and heat-labile enterotoxin-based mucosal adjuvants, and physical adjuvants, are also able to broaden influenza vaccine-induced immune responses against non-vaccine strains. This review focuses on introducing the various types of adjuvants capable of assisting current influenza vaccines to induce cross-protective immunity in preclinical and clinical studies. Mechanisms of licensed MF59 and AS03 adjuvants to induce cross-protective immunity are also introduced. Vaccine adjuvants hold a great promise to adjuvant influenza vaccines to induce cross-protective immunity.

• The immune response to aIIV3 is superior to IIV3 in pediatric subjects (N = 11,942). • More children achieve protective HI antibody responses with aIIV3 than with IIV3. • aIIV3 has higher immune responses than IIV3 to homologous and heterologous strains. • Absolute and relative efficacy against influenza were higher with aIIV3 than IIV3. • Solicited AEs, mostly mild to moderate in severity, were more frequent with aIIV3. To demonstrate the potential of an MF59-adjuvanted inactivated trivalent seasonal influenza vaccine (aIIV3; Fluad™) to improve the immune response in young children, we review the immunogenicity, efficacy, and safety/tolerability of aIIV3 from a comprehensive clinical development program in a pediatric population with a specific need for improved influenza vaccines. Data were analyzed from a series of 1 phase Ib, 3 phase II, and 2 phase III studies involving 11,942 children aged 6 months through 5 years. The clinical data showed that aIIV3 had statistically significantly greater immunogenicity and efficacy in the prevention of influenza compared to conventional inactivated trivalent seasonal influenza vaccines (IIV3s). The safety profile of aIIV3 was generally similar to that of nonadjuvanted IIV3, apart from an increased frequency of solicited adverse events (AEs) following vaccination. The majority of solicited AEs were mild or moderate in severity and resolved within 1 to 3 days. aIIV3 was well tolerated, with immunogenicity and efficacy exceeding that of conventional IIV3 in children 6 months through 5 years of age. The MF59-adjuvanted vaccine has the potential to fulfill an unmet clinical need in the prevention of seasonal influenza in this age group. [ABSTRACT FROM AUTHOR]

• In young children at risk of influenza complications, MF59-adjuvanted trivalent inactivated influenza vaccine (aIIV3) was well-tolerated. • The safety profile of aIIV3 is similar in children at risk/not at risk of influenza complications. • aIIV3 has higher immunogenicity than IIV3 in children at risk of influenza complications. To assess the safety and immunogenicity of the MF59-adjuvanted seasonal trivalent inactivated influenza vaccine (aIIV3; Fluad) in children aged 6 months through 5 years who are at risk of influenza complications. A retrospective analysis was performed to examine unsolicited adverse events (AEs) in an integrated dataset from six randomized clinical studies that compared aIIV3 with non-adjuvanted inactivated influenza vaccines (IIV3). The integrated safety set comprised 10 784 children, of whom 373 (3%) were at risk of influenza complications. The at-risk safety population comprised 373 children aged 6 months through 5 years: 179 received aIIV3 and 194 received non-adjuvanted IIV3 (128 subjects received a licensed IIV3). The most important risk factors were respiratory system illnesses (62–70%) and infectious and parasitic diseases (33–39%). During the treatment period, unsolicited AEs occurred in 54% of at-risk children and 55% of healthy children who received aIIV3; of those receiving licensed IIV3, 59% of at-risk and 62% of healthy subjects reported an unsolicited AE. The most common AEs were infections, including upper respiratory tract infection. Serious AEs (SAEs) were reported in <10% of at-risk subjects, and no vaccine-related SAEs were observed. In the immunogenicity subset (involving 103 participants from one study), geometric mean titers (GMTs) were approximately 2- to 3-fold higher with aIIV3 than with IIV3 for all three homologous strains (A/H1N1, A/H3N2, and B). Seroconversion rates were high for both aIIV3 (79–96%) and IIV3 (83–89%). In young children at risk of influenza complications, aIIV3 was well-tolerated and had a safety profile that was generally similar to that of non-adjuvanted IIV3. Similar to the not-at-risk population, the immune response in at-risk subjects receiving aIIV3 was increased over those receiving IIV3, suggesting aIIV3 is a valuable option in young children at risk of influenza complications. [ABSTRACT FROM AUTHOR]

• A meta-analysis of influenza vaccine trials spanning 21 years was conducted. • Antibody responses are significantly higher with aIIV3 than IIV3 in the elderly. • These results support the enhanced efficacy and safety of aIIV3 in older adults. Compare the immunogenicity of MF59-adjuvanted trivalent inactivated influenza vaccine (aIIV3; Fluad™) versus conventional trivalent inactivated influenza vaccine (IIV3) in an integrated dataset using a meta-analysis. In a meta-analysis, the immunogenicity of aIIV3 in subjects ≥65 years of age was compared with IIV3 immunogenicity using hemagglutination inhibition assay results from 23 phase I through III randomized controlled trials, including 16 first-dose vaccination studies and 7 revaccination studies assessing immunogenicity after second or third annual vaccination. The full analysis set consisted of 11,105 subjects (5869 aIIV3 and 5236 IIV3). In the revaccination studies, 822 individuals received 2 consecutive annual influenza vaccinations (492 aIIV3 and 330 IIV3), and 237 received 3 (150 aIIV3 and 87 IIV3). Overall, across all strains, the meta-analyzed point estimates for seroconversion (SC) and geometric mean titer (GMT) ratio were significantly higher for aIIV3 versus IIV3. The meta-analyzed percent differences in SC with corresponding 95% confidence intervals (CI) for A/H1N1, A/H3N2, and B strain were 9.5% (5.2–13.9), 10.5% (6.6–14.5), and 12.7% (8.6–16.8), respectively. The meta-analyzed GMT ratios with corresponding 95% CI for A/H1N1, A/H3N2, and B strain were 1.15 (1.01–1.31), 1.30 (1.18–1.44), 1.23 (1.15–1.31). Antibody responses against heterologous influenza strains were also significantly higher with aIIV3. Revaccination studies showed continued robust immune response to aIIV3 with repeated vaccination. aIIV3 elicited a statistically significantly greater immune response compared to conventional IIV3 in older adults, increasing the breadth and duration of the immune response. [ABSTRACT FROM AUTHOR]

• Safety of aIIV3 was analyzed with a large clinical trial and surveillance dataset. • aIIV3 and comparator were associated with similar AE rates. • In revaccination studies, aIIV3 AEs increased in Year 2 but decreased in Year 3. • No evidence suggests aIIV3 is associated with higher risk of immune-mediated AEs. To assess the long-term safety of MF59-adjuvanted trivalent influenza vaccine (aIIV3; Fluad™) in adults ≥65 years of age. Data from 36 primary vaccination and 7 re-vaccination Phase I through III trials were analyzed; 7532 subjects received aIIV3 and 5198 subjects a nonadjuvanted trivalent inactivated influenza vaccine (IIV3). These trials were evaluated in 2 data poolings: first-dose randomized controlled trials (FD-RCT) and revaccination trials. Spontaneously reported adverse events (AEs) from post-marketing surveillance were also analyzed. The percentages of subjects reporting AEs following vaccination were similar between aIIV3 and IIV3: 24.8% for aIIV3 vs 26.7% for IIV3 (relative risk [RR] 0.94; 95% confidence interval [CI] 0.87–1.01). The percentage of subjects with serious AEs was 6.7% for aIIV3 vs 7.0% for IIV3 (RR 0.95; 95% CI 0.82–1.09). Percentages of subjects with AEs leading to withdrawal, hospitalizations, adverse events of special interest (AESIs), and deaths between vaccination groups were similar. There was no signal of disproportionality for AESIs associated with aIIV3 compared to IIV3 in the post-marketing database. This integrated safety analysis demonstrates an acceptable safety profile for aIIV3 in adults ≥65 years of age. [ABSTRACT FROM AUTHOR]

Abstract Background As part of the U.S. Department of Health and Human Services (HHS) Pandemic Influenza Plan preparedness and response strategy, the National Pre-Pandemic Influenza Vaccine Stockpile (NPIVS) program was established by the Biomedical Advanced Research and Development Authority (BARDA) in 2005 with the goal of building and maintaining a stockpile of vaccines for influenza viruses with pandemic potential to vaccinate 20 million people in the critical workforce in the event of a pandemic. The NPIVS program continuously monitors the integrity of influenza vaccine antigens and adjuvants stored within the stockpile. In addition to monitoring physical and chemical properties in stability studies, it is important to regularly assess the safety and immunogenicity of stockpiled vaccines and adjuvants to maintain preparedness for use in the event of an influenza pandemic. Methods BARDA conducted a randomized, double-blinded Phase 2 clinical study with the oldest stockpiled influenza A(H5N1) antigen, stored over the previous 10–12 years administered with or without MF59® adjuvant, stored over the previous 2–7 years at the time of vaccination. Results Stockpiled vaccines were well-tolerated, adverse events were generally mild, and there was no drop in immunogenicity to the oldest stockpiled A(H5N1) vaccine. Compared to unadjuvanted vaccine, greater peak antibody responses were observed in subjects who were vaccinated with MF59-adjuvanted vaccines, regardless of antigen dose. Vaccination with the A(H5N1) vaccine antigen also results in cross-reactive antibody responses to contemporary circulating strains of A(H5) influenza viruses. Conclusions The frequency, type, and severity of AEs observed during this study are similar to historical clinical study data with A(H5N1) vaccines and MF59 adjuvant indicating that a stockpiled A(H5N1) vaccine appears to remain safe and tolerable. The vaccines were immunogenic when administered as a two-dose vaccine regimen in healthy adults, despite extended storage of HA antigen or MF59 adjuvant within the NPIVS. Trial registration: ClinicalTrials.gov : NCT02680002. [ABSTRACT FROM AUTHOR]

Backgroud: Influenza vaccination is recommended for adults aged >65 years as they are at high risk of significant morbidity and mortality. This open-label, multicenter, post-marketing surveillance study assessed the safety of the MF59-adjuvanted trivalent inactivated subunit influenza vaccine, which is marketed as FLUAD® and VANTAPLU®, in South Korean subjects aged >65 years. Materials and Methods: Solicited local and systemic adverse events (AEs) were collected from day 1 to 4 of the study. All unsolicited AEs and serious AEs (SAEs) were recorded from day 1 until study termination (day 29). Results: Of the 770 subjects enrolled (FLUAD®, n = 389; VANTAFLU®, n = 381), 39% overall experienced any solicited AE. Local AEs were reported by 33% of subjects overall； with the most common events being injection-site pain (30%) and tenderness (27%). Systemic AEs were reported by 19% of subjects overall with the most common events being myalgia (11%) and fatigue (8%). Conclusion： These results show that the MF59-adjuvanted influenza vaccine known as FLUAD® or VANTAFLU® had acceptable safety profiles in older adults (aged >65 years) in South Korea. [ABSTRACT FROM AUTHOR]

Abstract Background In 2010, a safety signal was detected for narcolepsy following vaccination with Pandemrix, an AS03-adjuvanted monovalent pandemic H1N1 influenza (pH1N1) vaccine. To further assess a possible association and inform policy on future use of adjuvants, we conducted a multi-country study of narcolepsy and adjuvanted pH1N1 vaccines. Methods We used electronic health databases to conduct a dynamic retrospective cohort study to assess narcolepsy incidence rates (IR) before and during pH1N1 virus circulation, and after pH1N1 vaccination campaigns in Canada, Denmark, Spain, Sweden, Taiwan, the Netherlands, and the United Kingdom. Using a case-control study design, we evaluated the risk of narcolepsy following AS03- and MF59-adjuvanted pH1N1 vaccines in Argentina, Canada, Spain, Switzerland, Taiwan, and the Netherlands. In the Netherlands, we also conducted a case-coverage study in children born between 2004 and 2009. Results No changes in narcolepsy IRs were observed in any periods in single study sites except Sweden and Taiwan; in Taiwan incidence increased after wild-type pH1N1 virus circulation and in Sweden (a previously identified signaling country), incidence increased after the start of pH1N1 vaccination. No association was observed for Arepanrix-AS03 or Focetria-MF59 adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the case-control study nor for children born between 2004 and 2009 in the Netherlands case-coverage study for Pandemrix-AS03. Conclusions Other than elevated narcolepsy IRs in the period after vaccination campaigns in Sweden, we did not find an association between AS03- or MF59-adjuvanted pH1N1 vaccines and narcolepsy in children or adults in the sites studied, although power to evaluate the AS03-adjuvanted Pandemrix brand vaccine was limited in our study. [ABSTRACT FROM AUTHOR]

Influenza is a major cause of respiratory disease leading to hospitalization in young children. However, seasonal trivalent influenza vaccines (TIVs) have been shown to be ineffective and poorly immunogenic in this population. The development of live-attenuated influenza vaccines and adjuvanted vaccines are important advances in the prevention of influenza in young children. The oil-in-water emulsions MF59 and adjuvant systems 03 (AS03) have been used as adjuvants in both seasonal adjuvanted trivalent influenza vaccines (ATIVs) and pandemic monovalent influenza vaccines. Compared with non-adjuvanted vaccine responses, these vaccines induce a more robust and persistent antibody response for both homologous and heterologous influenza strains in infants and young children. Evidence of a significant improvement in vaccine efficacy with these adjuvanted vaccines resulted in the use of the monovalent (A/H1N1) AS03-adjuvanted vaccine in children in the 2009 influenza pandemic and the licensure of the seasonal MF59 ATIV for children aged 6 months to 2 years in Canada. The mechanism of action of MF59 and AS03 remains unclear. Adjuvants such as MF59 induce proinflammatory cytokines and chemokines, including CXCL10, but independently of type-1 interferon. This proinflammatory response is associated with improved recruitment, activation and maturation of antigen presenting cells at the injection site. In young children MF59 ATIV produced more homogenous and robust transcriptional responses, more similar to adult-like patterns, than did TIV. Early gene signatures characteristic of the innate immune response, which correlated with antibody titers were also identified. Differences were detected when comparing child and adult responses including opposite trends in gene set enrichment at day 3 postvaccination and, unlike adult data, a lack of correlation between magnitude of plasmablast response at day 7 and antibody titers at day 28 in children. These insights show the utility of novel approaches in understanding new adjuvants and their importance for developing improved influenza vaccines for children.

Most of the complications and deaths related to seasonal flu occur in the elderly population (≥65 years) with comorbidities, and the influenza vaccine is the most effective way to prevent them. Immunization is less effective in older adults due to immunosenescence. MF59-adjuvanted vaccines, designed to improve the magnitude, persistence and amplitude of the immune response in elderly people, have been used in clinical practice since 1997 in their trivalent formulation and, since 2020, in their tetravalent formulation. Data from various studies show that these vaccines are not only safe for all age groups, with a reactogenicity profile similar to that of the conventional vaccine, but also that they are especially effective in boosting the immune response in the population aged 65 or over by increasing antibody titers after vaccination and significantly reducing the risk of hospital admission. Adjuvanted vaccines have been shown to provide cross-protection against heterologous strains and to be as effective as the high-dose vaccine in the population aged 65 or over. In this review, the scientific evidence on the efficacy and effectiveness of the MF59-adjuvanted vaccine in real clinical practice in people ≥65 years of age is analyzed through a narrative and descriptive review of the literature with data from clinical trials, observational studies and systematic reviews or meta-analysis., (©The Author 2023. Published by Sociedad Española de Quimioterapia. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)(https://creativecommons.org/licenses/by-nc/4.0/).)

Malignant tumors pose a public health problem that jeopardizes human life and quality of living. At present, tumor vaccines in clinical research typically are aimed at stimulating the cellular immune response, while more effective vaccines should take into account the synergy between broad spectrum antibodies and high levels of cellular immunity. In this study, epitope peptides (68–81, 95–104, 80–88) of the tumor antigen survivin were chosen as immunogens and supplemented with poly(I:C) and/or MF59 adjuvant to evaluate the immune effects and anti‐melanoma activities. The results indicated that poly(I:C) and MF59 could assist the survivin epitope peptide immunogen to control the tumor size, quality, and volume in black melanoma mouse models. Analyses by antibody titering, antibody isotyping and ELISPOT suggested that the adjuvanted immunogen could induce humoral immunity in mice. Poly(I:C) and MF59 combined with survivin peptide 95–104 could effectively induce humoral immunity mediated by type 2 T helper (Th2) cells. This study provides a basis for candidate immunogen design based on survivin and provides support for tumor therapy that can induce a more balanced Th1/Th2 immune response. [ABSTRACT FROM AUTHOR]

Influenza is a major cause of respiratory disease leading to hospitalization in young children. However, seasonal trivalent influenza vaccines (TIVs) have been shown to be ineffective and poorly immunogenic in this population. The development of liveattenuated influenza vaccines and adjuvanted vaccines are important advances in the prevention of influenza in young children. The oil-in-water emulsions MF59 and adjuvant systems 03 (AS03) have been used as adjuvants in both seasonal adjuvanted trivalent influenza vaccines (ATIVs) and pandemic monovalent influenza vaccines. Compared with non-adjuvanted vaccine responses, these vaccines induce a more robust and persistent antibody response for both homologous and heterologous influenza strains in infants and young children. Evidence of a significant improvement in vaccine efficacy with these adjuvanted vaccines resulted in the use of the monovalent (A/H1N1) AS03-adjuvanted vaccine in children in the 2009 influenza pandemic and the licensure of the seasonal MF59 ATIV for children aged 6 months to 2 years in Canada. The mechanism of action of MF59 and AS03 remains unclear. Adjuvants such as MF59 induce proinflammatory cytokines and chemokines, including CXCL10, but independently of type-1 interferon. This proinflammatory response is associated with improved recruitment, activation and maturation of antigen presenting cells at the injection site. In young children MF59 ATIV produced more homogenous and robust transcriptional responses, more similar to adult-like patterns, than did TIV. Early gene signatures characteristic of the innate immune response, which correlated with antibody titers were also identified. Differences were detected when comparing child and adult responses including opposite trends in gene set enrichment at day 3 postvaccination and, unlike adult data, a lack of correlation between magnitude of plasmablast response at day 7 and antibody titers at day 28 in children. These insights show the utility of novel approaches in understanding new adjuvants and their importance for developing improved influenza vaccines for children. [ABSTRACT FROM AUTHOR]

H7N9 influenza infection in humans would result in severe respiratory illness. Vaccination is the best way to prevent influenza virus. In this paper, we investigated the effect of early protection provided by inactivated whole-virion H7N9 influenza vaccine in a mouse model. Mice were immunized intramuscularly once with different doses of inactivated whole-virion H7N9 influenza vaccine alone or in combination with MF59 adjuvant. Specific IgM and IgG antibody titers in sera of mice were detected by ELISA 3, 5 and 7days after immunization. To evaluate the early protection provided by the vaccine, mice were challenged with lethal dose (40LD 50 ) of homologous virus 3, 5 and 7 days after immunization respectively. The survival rate and body weight change of mice during 21 days after challenge and the residual lung virus titer on 3rd day after challenge were determined. The results demonstrated that mice could obtain effective protection 3 days after immunization with the vaccine at a high dose, and 5–7 days after immunization even at a low dose. Thus early immune responses induced by inactivated whole-virion H7N9 vaccine could provide effective protection. [ABSTRACT FROM AUTHOR]