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Background: The rapid development, approval, and distribution of these vaccines highlight the need to carefully assess their safety. One significant concern is the incidence of Adverse Events Following Immunization (AEFI). There are few reports on the factors influencing AEFI and differences in AEFI among different COVID-19 vaccine brands in Thailand. Exploration of the incidence and factors related to post-vaccination adverse reactions against SARS-CoV-2 in the population attending vaccination centers in Thailand is considered pivotal. Objective: To investigate the incidence and factors associated with adverse events following the administration of the COVID-19 vaccine in the Ubon Ratchathani province. Methods: We analyzed data from individuals who received COVID-19 vaccinations in Ubon Ratchathani province between June 1, 2021, and July 31, 2022. Results: The study examined data from 2,955,978 COVID-19 vaccines administered in Ubon Ratchathani province. Among these, 3.34% experienced an AEFI, further categorized into events occurring within 30 min (0.17%) and after 30 min (3.19%) of vaccination. The occurrences were higher in females compared to males. The age groups exhibited distinct AEFI rates, with children aged 5-17 years and adults aged 18-60 years facing a higher risk. Additionally, individuals with comorbidities are more likely to experience AEFI. The brand of the vaccine and the number of doses administered also influenced AEFI rates. This comprehensive analysis provides valuable insights into AEFI reports, vaccine brands, and associated risk factors, and offers crucial information for vaccine safety monitoring and management. Conclusion: This COVID-19 vaccine adverse events study revealed that higher odds of adverse events were associated with being female, younger, having comorbidities, brand of vaccines, or getting over two doses. These findings provide valuable real-world safety information regarding different COVID-19 vaccines, aiding healthcare professionals and policymakers in effectively monitoring and managing vaccine-related AEFI. [ABSTRACT FROM AUTHOR]

ABSTRACTThis scoping review examines the role of digital solutions in active, participant-centered surveillance of adverse events following initial release of COVID-19 vaccines. The goals of this paper were to examine the existing literature surrounding digital solutions and technology used for active, participant centered, AEFI surveillance of novel COVID-19 vaccines approved by WHO. This paper also aimed to identify gaps in literature surrounding digital, active, participant centered AEFI surveillance systems and to identify and describe the core components of active, participant centered, digital surveillance systems being used for post-market AEFI surveillance of WHO approved COVID-19 vaccines, with a focus on the digital solutions and technology being used, the type of AEFI detected, and the populations under surveillance. The findings highlight the need for customized surveillance systems based on local contexts and the lessons learned to improve future vaccine monitoring and pandemic preparedness.

Hepatitis B vaccination is the most effective means of interrupting HBV transmission. Although the hepatitis B vaccine is very effective and safe, adverse events following immunization do occur and need to be reported so that problems can be identified and appropriate corrective action can be taken. Most of the research on AEFI focuses on the safety observation of newly used vaccines, and there are few long-term studies on AEFI of the hepatitis B vaccine. This study retrospectively analyzes the reporting rate, clinical symptoms, and onset time of AEFI of the hepatitis B vaccine in Quzhou from 2011 to 2023, and compares the differences in AEFI reporting rates between different types of hepatitis B vaccines, different vaccination ages, and different doses. The surveillance results show that from 2011 to 2023, the AEFI reporting rate of hepatitis B Vaccines in Quzhou was 17.55/100,000 doses. 98.73% of reported AEFI were non-serious. The types of AEFI reported were vaccine product-related reactions, immunization anxiety-related reactions, and coincidental events. 94.12% of vaccine product-related reactions occurred within 3 days, and the main symptoms were fever, local reactions at the injection site, and rash. The AEFI reporting rate of the CHO vaccine was higher than that of the yeast vaccines, and the probability of AEFI in children under 1 year of age receiving the hepatitis B vaccine was higher in the latter dose than in the previous dose. The 13-year-long AEFI surveillance provides reliable evidence of the safety of the hepatitis B vaccine.

Rotavin-M1 (POLYVAC) was licensed in Vietnam in 2012. The association of Rotavin-M1 with intussusception, a rare adverse event associated with rotavirus vaccines, and with adverse events following immunization (AEFI) have not been evaluated and monitored under conditions of routine use. From February 2017 to May 2021, we conducted a pilot introduction of Rotavin-M1 into the routine vaccination program in two provinces. Surveillance for intussusception was conducted at six sentinel hospitals. AEFI reports at 30 min and 7 days after vaccination were recorded. Among 443 children <12 months of age admitted for intussusception, most (92.3%) were children ≥ 6 months. Of the 388 children who were age-eligible to receive Rotavin-M1, 116 (29.9%) had received ≥1 dose. No intussusception cases occurred in the 1–21 days after dose 1 and one case occurred on day 21 after dose 2. Among the 45,367 children who received ≥1 dose of Rotavin-M1, 9.5% of children reported at least one AEFI after dose 1 and 7.3% after dose 2. Significantly higher AEFI rates occurred among children given Rotavin-M1 with pentavalent vaccines (Quinvaxem®, ComBE Five®) compared to Rotavin-M1 without pentavalent vaccines. There was no association between intussusception and Rotavin-M1. The vaccine was generally safe when administered alone and when co-administered with other vaccines. [ABSTRACT FROM AUTHOR]

Background To help distinguish vaccine-related adverse events following immunization (AEFI) from coincidental occurrences, active vaccine pharmacovigilance (VP) prospective surveillance programs are needed. From February to May 2021, we assessed the system and facility readiness for implementing active AEFI VP surveillance in Addis Ababa, Ethiopia. Methods Selected hospitals were assessed using a readiness assessment tool with scoring measures. The site assessment was conducted via in-person interviews within the specific departments in each hospital. We evaluated the system readiness with a desk review of AEFI guidelines, Expanded Program for Immunization Guidelines and Ethiopian Food and Drug Administration and Ethiopian Public Health Institute websites. Results Of the hospitals in Addis Ababa, 23.1% met the criteria for our site assessment. During the system readiness assessment, we found that essential components were in place. However, rules, regulations and proclamations pertaining to AEFI surveillance were absent. Based on the tool, the three hospitals (A, B and C) scored 60.6% (94/155), 48.3% (75/155) and 40% (62/155), respectively. Conclusions Only one of three hospitals assessed in our evaluation scored >50% for readiness to implement active AEFI surveillance. We also identified the following areas for improvement to ensure successful implementation: training, making guidelines and reporting forms available and ensuring a system that accommodates paper-based and electronic-based recording systems. [ABSTRACT FROM AUTHOR]

Abstract Background Tetanus remains a severe life-threatening infectious disease and neurological disorder in many parts of the world, where immunization programs are suboptimal. Any human injury or trauma has the possibility of getting infected with Clostridium tetani which is the sole causative bacterium of tetanus. Evidence is available that TAT may cause anaphylaxis and late serum sickness, while there has been no study conducted in Ethiopia. The Ethiopian Ministry of Health standard treatment guideline recommends tetanus prophylaxis for all tetanus-prone wounds. This study aimed to evaluate the safety of TAT administration in adults exposed to tetanus-prone wounds in Ethiopia. Methods The target product of this study was the equine tetanus antitoxin developed and manufactured by the ViNS Bioproducts Limited, India (Code: 130202084, A.W.No: 15/AAW/PI/02.00, DT: 25.04.2016). The product is delivered with the dose of 1000/1500 IU intramuscularly or subcutaneously to individuals at risk of tetanus infection for prophylactic purposes. The study was carried out in 11 healthcare facilities in Addis Ababa, Ethiopia, that had a relatively high clients load for tetanus-prone wounds. Medical records of patients with tetanus-prone wounds who received the equine TAT were reviewed retrospectively for any adverse events following immunization according to the World Health Organization (WHO) definition for adverse events following immunization (AEFI). Results There were more than 20,000 patients treated for trauma in the facilities from 2015 to 2019. Upon revision of available registration books, we identified 6000 charts to be eligible for the study, of which 1213 charts that had complete and reliable data on the AEFI profile of the TAT were included in the final analysis. The median age of the study participants was 26 years (IQR = 11 years, age range: 18–91 years) and 78% (949) were male. The tetanus-prone wounds resulted mainly from stab (44%, 535) and blunt force (30%, 362), and the most common sites of wounds were hand (22%, 270) and head (21%, 253). The most and least frequently occurring types of wounds were open wounds (77%, 930) and organ system injury (0.003%, 4), respectively. The mean time of presenting at health facilities from the onset of trauma was 2.96 h. Of the total 1231 participants, one male participant who presented within 3 h after experiencing a wound on his nose at the workplace had a severe local reaction immediately after injection of the TAT. No AEFI was recorded for the other participants. Conclusions The adverse event following immunization of the equine tetanus antitoxin produced by the ViNS Bioproducts Limited was very rare. A regular review of the product’s safety performance and systematic collection and analysis of adverse event reports are important to ensure the safety of the product.

Objective: Clinical clerkship students, as adolescent health workers, have been first recipients of the COVID-19 vaccination programme. The success rate and trust of recipients in the program have been impacted by adverse events following immunization (AEFI). This study aims to determine the AEFI of the CoronaVac vaccine among clinical clerkship students at the Faculty of Medicine, State Islamic University, Jakarta. Material and Methods: This study used cross sectional methods with a total of 225 subjects completing a questionnaire. The CoronaVac vaccine was administered twice with 2 week interval. AEFI was evaluated after 30 minutes, 24 hours, and on the third day. Results and discussion: 73.3% of the participants were female, 20-25 years old. AEFIs were found in 57.8 % of all participants in the first and second doses vaccination. The most common local AEFI was pain at the site injection, accounting 27.1 % which occurred 30 minutes after second dose vaccination. The most common systemic AEFI was drowsiness, accounting for 18 % which occurred 24 hours after first dose vaccination. Other systemic AEFIs were headache, fatigue, and chills. There was significant association between AEFIs and females but no significant association with history of allergy, comorbidities, and history of previous COVID-19. AEFIs were mild, no special treatment or hospitalization were required. Conclusion: The AEFIs of the CoronaVac vaccine among students were mild and had significant association with females. The study is expected to increase the public's confidence in the COVID-19 vaccination program and to create awareness of its safety. [ABSTRACT FROM AUTHOR]

The COVID-19 Pandemic has changed the global picture in the field of public health in the past few years. This critical time has made life very uncertain for everyone. Man has been constantly striving to discover measures to stop the spread of this deadly virus; the COVID-19 vaccine is one such endeavour. The fear and anxiety towards a new vaccine is high among the general public. With every new vaccination, constant monitoring and documentation of the vital happenings is very important. Thus, the reporting of Adverse events following immunization (AEFI) needs to be strengthened and implemented more efficiently to analyse the efficacy of this vaccination drive with respect to protection from the disease without causing any harmful adverse effects.

• Twenty-two of the participants (73 %) never experienced adverse effects following immunization (AEFI). • All reported AEFI occurred in eight patients and resolved within one week. • For no patient a metabolic deterioration or seizure was reported as AEFI. We here explore adverse events following immunization (AEFI) in children with mitochondrial disease (MD) recruited from two expertise centers in Austria (SALK) and The Netherlands (RUMC). Parents completed a questionnaire on the type of immunizations received and AEFI in a post-vaccination exposure period of seven days. 95 individuals were invited to this study, of whom 30 (median age 13.4 years) participated. Together these individuals had received 376 immunizations with a median of 12 vaccinations each. In 316 of 376 (84 %) vaccinations no AEFI occurred, 22 patients (73 %) never experienced any AEFI. Eight patients experienced 76 AEFI after 60 vaccinations, these were mild (redness (n = 9) /pain at injection site (n = 21), fever (n = 44), gastrointestinal complaints (n = 2)). None had a metabolic deterioration or seizures, no patient was admitted to the hospital. Although our data is limited by the small sample size, this may aid in discussing responsible immunization decisions with parents. [ABSTRACT FROM AUTHOR]

Rotavin-M1 (POLYVAC) was licensed in Vietnam in 2012. The association of Rotavin-M1 with intussusception, a rare adverse event associated with rotavirus vaccines, and with adverse events following immunization (AEFI) have not been evaluated and monitored under conditions of routine use. From February 2017 to May 2021, we conducted a pilot introduction of Rotavin-M1 into the routine vaccination program in two provinces. Surveillance for intussusception was conducted at six sentinel hospitals. AEFI reports at 30 min and 7 days after vaccination were recorded. Among 443 children ®, ComBE Five®) compared to Rotavin-M1 without pentavalent vaccines. There was no association between intussusception and Rotavin-M1. The vaccine was generally safe when administered alone and when co-administered with other vaccines.

ObjectiveTo determine the incidence and characteristics of adverse events following immunization （AEFI） in 2016‒2020 in Dazu District of Chongqing， and evaluate the AEFI surveillance information system and provide scientific evidence for vaccine safety.MethodsDescriptive epidemiological analysis was performed on the cases collected by the AEFI surveillance system. Incidence and coverage of AEFI were then presented.ResultsA total of 319 AEFI cases were reported in 2016‒2020. Reported incidence of AEFI was determined to be 24.64/105 doses. The proportion of timely reporting AEFI within 48 hours was 94.04% and that of timely investigation within 48 hours was 98.41%. The proportion of completing the AEFI survey was 100.00% and that of AEFI classification was 99.69%. The male to female ratio was 1.28∶1. Majority of the AEFI cases were less than 1 year old （64.26%， 205/319）， from April to September （68.97%， 220/319）， and reported at 0‒1 day post-immunization （89.34%， 285/319）. Moreover， the reported incidence differed significantly between time periods （χ2=32.481， P

The objective of this study is to assess the frequency and severity of adverse events following immunization (AEFI) in Indian children aged 5–17 years who received the Pfizer-BioNTech mRNA COVID-19 vaccine, as well as to investigate for predictors of AEFI. To examine AEFI following the first and second doses of Pfizer's vaccine, semi-structured questionnaires were distributed as Google forms at Indian schools in Saudi Arabia. The 385 responses included 48.1% male and 51.9% female children, with 136 responses of children aged 5–11 years (group A) and 249 responses from children aged 12–17 years (group B). Overall, 84.4% of children had two shots. The frequency of AEFI was reported to be higher after the first dose than after the second (OR = 2.12, 95% CI = 1.57–2.86). The reported AEFIs included myalgia, rhinitis, local reaction with fever, a temperature of 102 °F or higher, and mild to moderate injection site reactions. While group B frequently reported multiple AEFIs, group A typically reported just one. Local reaction with low grade fever was more frequently reported in group B after the first dose (24.1%) and second dose (15.4%), while local reaction without low grade fever was most frequently observed in group A after the first (36.8%) and second dose (30%). Only prior COVID-19 infection (OR = 2.98, 95% CI = 1.44–6.2) was associated with AEFI after the second dose in the study sample, whereas male gender (OR = 1.71, 95% CI = 1.13–2.6) and prior COVID-19 infection (OR = 2.95, 95% CI = 1.38–6.3) were predictors of AEFI after the first dose. Non-serious myocarditis was reported by only one child. According to the analysis conducted, the Pfizer's mRNA COVID-19 vaccination was found to be safe in Indian children. [ABSTRACT FROM AUTHOR]

Objective: A comparative analysis was performed to investigate the potential risk factors of Adverse Events Following Immunization (AEFI) after receiving different booster vaccines. Methods: From 18 January 2021 to 21 January 2022, the Health Care Workers (HCWs) of Guizhou Provincial Staff Hospital (Guizhou Province, China) who received a third Booster vaccine, that was either homologous (i.e., (i) a total of three doses of Vero cell vaccine or (ii) three doses of CHO cell vaccine) or (iii) heterologous with two first doses of Vero cell vaccine, being either CHO cell vaccine or adenovirus type-5 (Ad5) vectored COVID-19 vaccine, were asked to complete a self-report questionnaire form to provide information on any AEFI that may have occurred in the first 3 days after vaccination with the booster. The frequency of AEFI corresponding to the three different booster vaccines was compared, and the risk factors for predicting AEFI were determined by multivariate logistic regression analysis. Results: Of the 904 HCWs who completed the survey, 792 met the inclusion criteria. The rates of AEFI were 9.8% (62/635) in the homologous Vero cell booster group, 17.3% (13/75) in the homologous CHO cell booster group, and 20.7% (17/82) in the heterologous mixed vaccines booster group, and the rates were significantly different (c2 = 11.5, p = 0.004) between the three groups of vaccines. Multivariate logistic regression analysis showed that: (1) compared to the homologous Vero cell booster group, the risk of AEFI was about 2.1 times higher (OR = 2.095, 95% CI: 1.056-4.157, p = 0.034) in the CHO cell booster group and 2.5 times higher (OR = 2.476, 95% CI: 1.352-4.533, p = 0.003) in the mixed vaccines group; (2) the odds for women experiencing AEFI were about 2.8 times higher (OR = 2.792, 95% CI: 1.407-5.543, p = 0.003) than men; and (3) compared to the non-frontline HCWs, the risk of AEFI was about 2.6 times higher (OR = 2.648, 95% CI: 1.473-4.760, p = 0.001) in the doctors. Conclusion: The AEFI in all three booster groups are acceptable, and serious adverse events are rare. The risk of AEFI was higher in doctors, which may be related to the high stress during the COVID-19 epidemic. Support from government and non-governmental agencies is important for ensuring the physical and mental health of HCWs. [ABSTRACT FROM AUTHOR]

Abstract Background Vaccine hesitancy has been a growing challenge for public health in recent decades. Among factors contributing to vaccine hesitancy, concerns regarding vaccine safety and Adverse Events (AEs) play the leading role. Moreover, cognitive biases are critical in connecting such concerns to vaccine hesitancy behaviors, but their role has not been comprehensively studied. In this study, our first objective is to address concerns regarding vaccine AEs to increase vaccine acceptance. Our second objective is to identify the potential cognitive biases connecting vaccine hesitancy concerns to vaccine-hesitant behaviors and identify the mechanism they get triggered in the vaccine decision-making process. Methods First, to mitigate concerns regarding AEs, we quantitatively analyzed the U.S. Vaccine Adverse Event Reporting System (VAERS) from 2011 to 2018 and provided evidence regarding the non-severity of the AEs that can be used as a communicable summary to increase vaccine acceptance. Second, we focused on the vaccination decision-making process. We reviewed cognitive biases and vaccine hesitancy literature to identify the most potential cognitive biases that affect vaccine hesitancy and categorized them adopting the Precaution Adoption Process Model (PAPM). Results Our results show that the top frequent AEs are expected mild reactions like injection site erythema (4.29%), pyrexia (3.66%), and injection site swelling (3.21%). 94.5% of the reports are not serious and the average population-based serious reporting rate over the 8 years was 25.3 reports per 1 million population. We also identified 15 potential cognitive biases that might affect people’s vaccination decision-making and nudge them toward vaccine hesitancy. We categorized these biases based on the factors that trigger them and discussed how they contribute to vaccine hesitancy. Conclusions This paper provided an evidence-based communicable summary of VAERS. As the most trusted sources of vaccine information, health practitioners can use this summary to provide evidence-based vaccine information to vaccine decision-makers (patients/parents) and mitigate concerns over vaccine safety and AEs. In addition, we identified 15 potential cognitive biases that might affect the vaccination decision-making process and nudge people toward vaccine hesitancy. Any plan, intervention, and message to increase vaccination uptake should be modified to decrease the effect of these potential cognitive biases.

Adverse events following immunization (AEFIs), especially if serious, may impact vaccine recipients' quality of life and financial well-being and fuel vaccine hesitancy. Nigeria rolled out COVID-19 vaccination in 2021 with little known about the impact of AEFIs on an individual's quality of life. No study in Africa has explored the health and financial impact of AEFIs. We explored patient-reported outcomes (PROs) of adverse events after COVID-19 vaccination and documented the lived experiences of those with serious AEFIs to understand the effect on their health, financial well-being, and attitude to future vaccinations. We conducted a convergent mixed-methods study using the RAND 36-item health survey and in-depth interviews to collect PROs on vaccine recipients in Nigeria. Eight health scale scores and two summary composite scores were used to measure the health-related quality of life outcomes from the survey and inductive analysis was used to identify themes from the interview scripts. The results of both studies were integrated in a joint display to highlight areas of concordance. In total, 785 survey responses were analyzed (53% females, 68% aged 18–30 years). Responders reporting an AEFI were 58%, of whom 62% received the first dose only. Younger age and first vaccine dose (p <.001 respectively) were associated with experiencing an AEFI. Not reporting an AEFI was associated with better quality of life, measured as higher scores on all eight SF-36 Health scales and the physical and mental component summary scores. All six interviewees with serious AEFIs experienced physical, mental, and financial distress. Some expressed a strong negative attitude toward future COVID-19 vaccinations but not toward vaccines for routine immunization. AEFIs negatively impact the health and financial well-being of affected individuals and their attitude to future vaccinations, especially if serious. Understanding the impact of AEFIs on people is important and should inform future policies and interventions. The results of our study can inform policy and planning for future mass vaccination campaigns in LMICs. • Adverse events negatively affected vaccine recipients' health related quality of life. • Serious AEFIs impact recipients' health and financial well-being. • Individual experiences with the system established to support those with AEFI varied. • Outcomes that are important to individuals should inform policy planning and implementation. [ABSTRACT FROM AUTHOR]

Introduction: Domestic Sabin-strain inactivated poliovirus vaccine (sIPV) was approved for use in China in 2015 and introduced into the national immunization schedule in a sequential schedule with oral poliovirus vaccine (OPV) in May 2016. However, a comprehensive analysis describing the characteristics, occurrences, and incidences of adverse events following immunization (AEFI) with sIPV in China is lacking., Methods: Data on sIPV doses administered and AEFI reported from 2015 to 2022 were obtained from the Chinese National Immunization Information System (CNIIS). Descriptive epidemiological methods and statistics were used to analyze and describe the characteristics, occurrences, and incidences of AEFI following sIPV in China from 2015 to 2022., Results: From 2015 to 2022, over 110,000,000 sIPV doses were administered, and 46,748 sIPV AEFIs were reported, resulting in an AEFI reporting rate of 42.44/100,000. Most AEFIs (46,333, 99.11%) were non-serious. Causality assessment determined 46,061 (98.53%) AEFIs were vaccine product-related reactions, including 44,001 (94.12%) common and 2,060 (4.41%) rare vaccine reactions. Among common vaccine reactions, reporting rates for fever >38.5 °C, local redness and swelling ≥2.6 cm, and local induration ≥2.6 cm were 12.02/100,000, 5.13/100,000, and 1.67/100,000, respectively. Among rare vaccine reactions, reporting rates for anaphylactic rash, thrombocytopenic purpura, and febrile convulsion were 1.56/100,000, 0.09/100,000, and 0.03/100,000, respectively., Conclusions: Most reported sIPV AEFIs were non-serious, and the reporting rate of rare vaccine reactions has been very low since sIPV was approved for use in China. As sIPV remains in use in China, surveillance of AEFIs associated with this vaccine needs to be maintained., Competing Interests: No conflicts of interest., (Copyright © 2024 by Chinese Center for Disease Control and Prevention.)

The objective of this study is to assess the frequency and severity of adverse events following immunization (AEFI) in Indian children aged 5–17 years who received the Pfizer-BioNTech mRNA COVID-19 vaccine, as well as to investigate for predictors of AEFI. To examine AEFI following the first and second doses of Pfizer’s vaccine, semi-structured questionnaires were distributed as Google forms at Indian schools in Saudi Arabia. The 385 responses included 48.1% male and 51.9% female children, with 136 responses of children aged 5–11 years (group A) and 249 responses from children aged 12–17 years (group B). Overall, 84.4% of children had two shots. The frequency of AEFI was reported to be higher after the first dose than after the second (OR = 2.12, 95% CI = 1.57–2.86). The reported AEFIs included myalgia, rhinitis, local reaction with fever, a temperature of 102 °F or higher, and mild to moderate injection site reactions. While group B frequently reported multiple AEFIs, group A typically reported just one. Local reaction with low grade fever was more frequently reported in group B after the first dose (24.1%) and second dose (15.4%), while local reaction without low grade fever was most frequently observed in group A after the first (36.8%) and second dose (30%). Only prior COVID-19 infection (OR = 2.98, 95% CI = 1.44–6.2) was associated with AEFI after the second dose in the study sample, whereas male gender (OR = 1.71, 95% CI = 1.13–2.6) and prior COVID-19 infection (OR = 2.95, 95% CI = 1.38–6.3) were predictors of AEFI after the first dose. Non-serious myocarditis was reported by only one child. According to the analysis conducted, the Pfizer’s mRNA COVID-19 vaccination was found to be safe in Indian children.

Despite the proposed ethical link between mandatory immunization and Vaccine Injury Support Programs (VISPs), relatively few jurisdictions, even those with mandatory immunization, have implemented such programs. Although it may be assumed that individuals injured by a vaccine in a non-VISP country receive less support than in countries possessing such programs, the extent of the discrepancy is not clear; nor is the nature of any discrepancy. In our 2018 survey of 28 Global NITAG (National Immunization Technical Advisory Group) Network (GNN) countries, we asked respondents about mandatory immunization and the availability of VISPs. Responses were supplemented with desktop research and review of scholarly literature for further information regarding VISP availability and details. Although only two of 14 (14%) surveyed jurisdictions with mandatory immunization had formal VISPs, responses from additional countries suggested the presence of less formal avenues of compensation for serious Adverse Events Following Immunization (AEFIs); similarly, we found five of 15 (33%) of countries without mandatory immunization had implemented formal VISPs, but another three such countries suggested similar informal methods of compensation. From our data, it is evident that at least some countries with mandatory immunization may discharge their (perceived or actual) ethical obligation to provide financial assistance to vaccine-injured individuals through more informal avenues rather than structured VISPs, although the extent and impact of this practice is by its nature difficult to assess. Further, the nature of VISPs may vary significantly from jurisdiction to jurisdiction, and simple VISP/non-VISP classification of jurisdiction may fail to capture nuance in support for AEFI victims in many jurisdictions. Future assessments of VISPs should consider the possibility of these more informal avenues of support for vaccine injuries. [ABSTRACT FROM AUTHOR]

Background: Vaccine hesitancy has been a growing challenge for public health in recent decades. Among factors contributing to vaccine hesitancy, concerns regarding vaccine safety and Adverse Events (AEs) play the leading role. Moreover, cognitive biases are critical in connecting such concerns to vaccine hesitancy behaviors, but their role has not been comprehensively studied. In this study, our first objective is to address concerns regarding vaccine AEs to increase vaccine acceptance. Our second objective is to identify the potential cognitive biases connecting vaccine hesitancy concerns to vaccine-hesitant behaviors and identify the mechanism they get triggered in the vaccine decision-making process.Methods: First, to mitigate concerns regarding AEs, we quantitatively analyzed the U.S. Vaccine Adverse Event Reporting System (VAERS) from 2011 to 2018 and provided evidence regarding the non-severity of the AEs that can be used as a communicable summary to increase vaccine acceptance. Second, we focused on the vaccination decision-making process. We reviewed cognitive biases and vaccine hesitancy literature to identify the most potential cognitive biases that affect vaccine hesitancy and categorized them adopting the Precaution Adoption Process Model (PAPM).Results: Our results show that the top frequent AEs are expected mild reactions like injection site erythema (4.29%), pyrexia (3.66%), and injection site swelling (3.21%). 94.5% of the reports are not serious and the average population-based serious reporting rate over the 8 years was 25.3 reports per 1 million population. We also identified 15 potential cognitive biases that might affect people's vaccination decision-making and nudge them toward vaccine hesitancy. We categorized these biases based on the factors that trigger them and discussed how they contribute to vaccine hesitancy.Conclusions: This paper provided an evidence-based communicable summary of VAERS. As the most trusted sources of vaccine information, health practitioners can use this summary to provide evidence-based vaccine information to vaccine decision-makers (patients/parents) and mitigate concerns over vaccine safety and AEs. In addition, we identified 15 potential cognitive biases that might affect the vaccination decision-making process and nudge people toward vaccine hesitancy. Any plan, intervention, and message to increase vaccination uptake should be modified to decrease the effect of these potential cognitive biases. [ABSTRACT FROM AUTHOR]

“Non-specific effects” of vaccines go beyond the specific protective effects against the targeted diseases. They, if real, could theoretically be beneficial, neutral or negative. This article intends to answer the following questions: Do the non-specific effects of vaccines exist? Almost certainly yes, and they can be important in low-income countries Are non-specific effects also present in high-income countries? At least to some extent, it seems quite logical Can non-specific effects be systematically identified by the current systems of side effects/unintended reactions monitoring? Most likely not Could the Institute of Medicine proposals and some ongoing attempts solve the issue? It seems unlikely Could there be better, feasible and ethically acceptable ways to achieve the aforementioned objective? A proposal is presented about this issue, with the potential both to solve the problem with the most valid methods, and to overcome the ethical problems that have so far precluded the adoption of RCTs to study possible vaccine non-specific effects, monitored by long follow-up.

Immediate hypersensitivity reactions (IHR) are rare but potentially serious adverse events following immunization (AEFI). Surveillance of Adverse Events following Vaccination in the Community (SAEFVIC) is an enhanced passive surveillance system that collects, analyses and reports information about AEFI in Victoria, Australia. We describe the incidence, timing and type of potential IHR following vaccination in preschool children reported over an 8-year period. A total of 2110 AEFI were reported in 1620 children, of which 23.5% (496) were classified as potential IHR. Of these, 37.1% (184) were suspected to be IgE-mediated, (including anaphylaxis, angioedema and/or urticaria) and 83.5% (414) occurred within 15 minutes of vaccination. The incidence of potential IHR was 5.4 per 100,000 doses, with that of suspected IgE-mediated IHR being 2.0 per 100,000 doses. The incidence of anaphylaxis was extremely low (0.13 per 100,000 doses) and is consistent with other published studies. Potential IHR following immunization should be reported to appropriate local pharmacovigilance systems and patients reviewed by specialists able to evaluate, investigate and manage future vaccinations.

Live viral vectors that express heterologous antigens of the target pathogen are being investigated in the development of novel vaccines against serious infectious agents like HIV and Ebola. As some live recombinant vectored vaccines may be replication-competent, a key challenge is defining the length of time for monitoring potential adverse events following immunization (AEFI) in clinical trials and epidemiologic studies. This time period must be chosen with care and based on considerations of pre-clinical and clinical trials data, biological plausibility and practical feasibility. The available options include: (1) adapting from the current relevant regulatory guidelines; (2) convening a panel of experts to review the evidence from a systematic literature search to narrow down a list of likely potential or known AEFI and establish the optimal risk window(s); and (3) conducting "near real-time" prospective monitoring for unknown clustering's of AEFI in validated large linked vaccine safety databases using Rapid Cycle Analysis for pre-specified adverse events of special interest (AESI) and Treescan to identify previously unsuspected outcomes. The risk window established by any of these options could be used along with (4) establishing a registry of clinically validated pre-specified AESI to include in case-control studies. Depending on the infrastructure, human resources and databases available in different countries, the appropriate option or combination of options can be determined by regulatory agencies and investigators. [ABSTRACT FROM AUTHOR]

ABSTRACT Vaccination has been a successful strategy in influenza prevention. However, despite the safety and efficacy of the vaccines, they can cause adverse events following immunization (AEFI). Moreover, due to the vaccination success, most of vaccine-preventable diseases (VPD) have become rare, and public attention has been shifted from VPD to the AEFI associated with vaccination. This manuscript describes the safety of Instituto Butantan (IB) seasonal trivalent influenza vaccine (TIV) from 2013 to 2017. AEFI data were received by the Department of Pharmacovigilance of IB (PV-IB), from January the 1st 2013 to December the 31st 2017, and were recorded in an electronic database (OpenClinica©). PV-IB received 1,415 Individual Case Safety Reports (ICSR) associated with the TIV; 1,253 ICSR with at least one AEFI were analyzed and 4,140 AEFI were identified. The other 162 (11.4%) cases did not present any symptom. Among the total of AEFI, 405 (9.8%) were classified as serious. AEFI with the highest incidence rates per 100,000 doses of TIV were: “local pain” (0.28), “local erythema” (0.23), “local warmth” (0.22), “local swelling” (0.20) and “fever” (0.19). PV-IB received 175 (4.2%) occurrences of SAE of special interest, of which 75 (1.8%) anaphylaxis/anaphylactic reactions, 56 (1.4%) neurological syndromes (including seven Guillain-Barré Syndrome) and 44 (1.1%) convulsion/febrile convulsion. The results of this manuscript suggested that Instituto Butantan trivalent influenza vaccine (IB-TIV) is safe, as most of the reported AEFI were classified as non-serious. AEFI described for the IB-TIV are in agreement with the ones described in the literature for similar vaccines.

Vaccination has been a successful strategy in influenza prevention. However, despite the safety and efficacy of the vaccines, they can cause adverse events following immunization (AEFI). Moreover, due to the vaccination success, most of vaccine-preventable diseases (VPD) have become rare, and public attention has been shifted from VPD to the AEFI associated with vaccination. This manuscript describes the safety of Instituto Butantan (IB) seasonal trivalent influenza vaccine (TIV) from 2013 to 2017. AEFI data were received by the Department of Pharmacovigilance of IB (PV-IB), from January the 1st 2013 to December the 31st 2017, and were recorded in an electronic database (OpenClinica©). PV-IB received 1,415 Individual Case Safety Reports (ICSR) associated with the TIV; 1,253 ICSR with at least one AEFI were analyzed and 4,140 AEFI were identified. The other 162 (11.4%) cases did not present any symptom. Among the total of AEFI, 405 (9.8%) were classified as serious. AEFI with the highest incidence rates per 100,000 doses of TIV were: "local pain" (0.28), "local erythema" (0.23), "local warmth" (0.22), "local swelling" (0.20) and "fever" (0.19). PV-IB received 175 (4.2%) occurrences of SAE of special interest, of which 75 (1.8%) anaphylaxis/anaphylactic reactions, 56 (1.4%) neurological syndromes (including seven Guillain-Barré Syndrome) and 44 (1.1%) convulsion/febrile convulsion. The results of this manuscript suggested that Instituto Butantan trivalent influenza vaccine (IB-TIV) is safe, as most of the reported AEFI were classified as non-serious. AEFI described for the IB-TIV are in agreement with the ones described in the literature for similar vaccines. [ABSTRACT FROM AUTHOR]

Timely and effective evaluation of vaccine safety signals for newly developed vaccines introduced in low and middle- income countries (LMICs) is essential. The study tested the development of a global network of hospital-based sentinel sites for vaccine safety signal verification and hypothesis testing. Twenty-six sentinel sites in sixteen countries across all WHO regions participated, and 65% of the sites were from LMIC. We describe the process for the establishment and operationalization of such a network and the lessons learned in conducting a multi-country collaborative initiative. 24 out of the 26 sites successfully contributed data for the global analysis using standardised tools and procedures. Our study successfully confirmed the well-known risk estimates for the outcomes of interest. The main challenges faced by investigators were lack of adequate information in the medical records for case ascertainment and classification, and access to immunization data. The results suggest that sentinel hospitals intending to participate in vaccine safety studies strengthen their systems for discharge diagnosis coding, medical records and linkage to vaccination data. Our study confirms that a multi-country hospital-based network initiative for vaccine safety monitoring is feasible and demonstrates the validity and utility of large collaborative international studies to monitor the safety of new vaccines introduced in LMICs. [ABSTRACT FROM AUTHOR]

New vaccines designed to prevent diseases endemic in low and middle-income countries are being introduced without prior utilization in countries with robust vaccine pharmacovigilance systems. Our aim was to build capacity for active surveillance of vaccine adverse events in the Americas. We describe the implementation of a proof-of-concept study for the feasibility of an international collaborative hospital-based active surveillance system for vaccine safety. The study was developed and implemented in 15 sentinel sites located in seven countries of the region of the Americas, under the umbrella of the World Health Organization (WHO) Global Vaccine Safety Initiative. The study evaluated the associations between measles-mumps-rubella vaccines and two well-recognized adverse events: Immune thrombocytopenic purpura (ITP) and aseptic meningitis. The regional network contributed 63 confirmed ITP and 16 confirmed aseptic meningitis eligible cases to the global study, representing, respectively, 33% and 19% of the total cases. To ensure long-term sustainability and usefulness to investigate adverse events following new vaccine introductions in low and middle-income countries, the network needs to be strengthened with additional sites and integrated into national health systems. [ABSTRACT FROM AUTHOR]

INTRODUCTION: An estimated one hundred million African meningitis belt residents have received MenAfriVac, meningococcal serogroup A conjugate vaccine. Since October 2012 the vaccine has been licensed for use in a controlled temperature chain (CTC) approach, at temperatures of up to 40,C for up to four days. The Benin Ministry of Health conducted a pilot evaluation in one of its 34 health districts to assess whether the CTC approach was associated with increased adverse events following immunisation (AEFIs). METHODS: We compared the occurrence of AEFIs during the 5 days following immunisation for 4 villages in the district using the CTC approach to 4 villages in another district using the traditional approach (vaccine kept at +2 to +8,C). Severe events resulting in hospitalisation or death of non-interviewed household members also were recorded. RESULTS: We included 1000 persons in the CTC and 999 in the non-CTC group. Only mild and transient AEFIs were noted in both groups, such as pain at injection site or fever. Compared to the non-CTC group, the CTC group had similar or lower rates of AEFIs and the occurrence of AEFIs in both groups was similar to that indicated in the vaccine package insert. No case of hospitalisation or death occurred among interviewed and non-interviewed household members. CONCLUSION: The CTC approach, as implemented in Benin, was not associated with an increased rate of adverse events in the five days following immunisation, either when compared to a concurrent non-CTC population or to previous studies.

Surveillance for adverse events following immunization (AEFI) is an important component of any national immunization program. In the People's Republic of China (China), a populous, middle-income country, development of an AEFI surveillance system began in 2005. In 2008, the AEFI surveillance system was implemented as a nationwide, online system and called the Chinese National AEFI Information System (CNAEFIS). Since then, CNAEFIS has provided useful, national-level data on vaccine safety. National AEFI surveillance guidelines were issued jointly by the Ministry of Health and the China Food and Drug Administration in 2010. This article reviews the development, status, and key aspects of the Chinese AEFI surveillance system, and describes challenges and future plans for vaccine safety assessment in China. [ABSTRACT FROM AUTHOR]

Highlights: [•] Brighton Collaboration has created case definitions for adverse event following immunization. [•] We converted the case definition for anaphylaxis into a more user-friendly algorithm. [•] The algorithm was more efficient than the case definition for evaluating an anaphylaxis case. [ABSTRACT FROM AUTHOR]

Introduction: An estimated one hundred million African meningitis belt residents have received MenAfriVac®meningococcal serogroup A conjugate vaccine. Since October 2012 the vaccine has been licensed for use in a controlled temperature chain (CTC) approach, at temperatures of up to 40°C for up to four days. The Benin Ministry of Health conducted a pilot evaluation in one of its 34 health districts to assess whether the CTC approach was associated with increased adverse events following immunisation (AEFIs). Methods: We compared the occurrence of AEFIs during the 5 days following immunisation for 4 villages in the district using the CTC approach to 4 villages in another district using the traditional approach (vaccine kept at +2 to +8°C). Severe events resulting in hospitalisation or death of non-interviewed household members also were recorded. Results: We included 1000 persons in the CTC and 999 in the non-CTC group. Only mild and transient AEFIs were noted in both groups, such as pain at injection site or fever. Compared to the non-CTC group, the CTC group had similar or lower rates of AEFIs and the occurrence of AEFIs in both groups was similar to that indicated in the vaccine package insert. No case of hospitalisation or death occurred among interviewed and noninterviewed household members. Conclusion: The CTC approach, as implemented in Benin, was not associated with an increased rate of adverse events in the five days following immunisation, either when compared to a concurrent non-CTC population or to previous studies. [ABSTRACT FROM AUTHOR]

Highlights: [•] Reviewed, re-analyzed literature pertaining to YEL-AVD among the elderly. [•] Lack of strong evidence for contraindication of yellow fever vaccine. [•] Recommend caution when physicians administer the yellow fever vaccine. [•] Ensure yellow fever vaccine is only given when benefits outweigh risks. [Copyright &y& Elsevier]

Highlights: [•] Global collaboration is feasible and enables comparison of vaccine formulations. [•] Exposure to pandemic H1N1 vaccines was associated with a slight increased risk of GBS. [•] Adjuvanted vaccines were not associated with higher GBS risk as compared to non-adjuvanted vaccines. [•] Results from pooled (mega-analytic) and meta-analytic approaches were consistent. [•] Low relative incidence of GBS supports recommendations for use of influenza vaccines. [ABSTRACT FROM AUTHOR]

Immunization plays an important role in achieving global health goals. Thus, vaccination is one of the essential means of preventing infectious and viral diseases. The onset of adverse events following immunization (AEFI) is common and most of the time it is a mild effect. However, stimulating the immune system during critical periods of brain development can lead to neurological effects. Among the neurological effects, we were interested in this work by seizures appearing following vaccination., (Copyright © 2022 Société française de pharmacologie et de thérapeutique. Published by Elsevier Masson SAS. All rights reserved.)

Abstract: Introduction: MenAfriVac is a new conjugate vaccine against Neisseria meningitidis serogroup A, the major cause of meningitis outbreaks in sub-Saharan Africa. In Niger, the MenAfriVac introduction campaign was conducted in the District of Filingue, during September 2010, targeting 392,211 individuals aged 1–29 years. We set up an enhanced spontaneous surveillance system to monitor adverse events following immunization (AEFI) during the campaign period and 42 days thereafter. Methods: All the 33 health centres of the district have been designated as surveillance units, which reported AEFIs on a daily basis to the health district headquarters. Health care workers were instructed to screen patients presenting with predefined conditions of interest and patients spontaneously presenting at units or at vaccination posts with complaints after vaccination. Cases were classified as serious (resulting in death, hospitalization or long-term disability) or minor. A National Expert Committee was established to determine if serious cases were causally associated with the vaccine. Results: In total, 356,532 vaccine doses were administered. During 61 days of monitoring, 82 suspected AEFIs were reported: 16 severe and 66 minor. The cumulative incidence was of 23.0 per 100,000 doses. Among severe cases, 14 were classified as coincidences, one urticaria complicated by respiratory distress was classified as a probable vaccine reaction, and one death was unclassifiable because post-mortem information was unavailable. The number of units that reported at least one case was 19/33 (57.6%). Conclusions: Although these results are limited by underreporting of cases, we did not identify safety concerns with MenAfriVac. The lessons learned from this experience should be used to reinforce the national pharmacovigilance system in Niger to make it complaint with international standards. In order to do so, we recommend using a lighter system for routine; and conducting regular training and supervisory activities to increase its acceptance among local health workers. [Copyright &y& Elsevier]

Abstract: A survey conducted among 26 European Countries within the Vaccine European New Integrated Collaboration Effort (VENICE) project assessed the status of organization in prevention and management of adverse events following immunization (AEFI) and level of interconnection, with the aim at individuating points of strength and weakness. The emerging picture is for a strong political commitment to control AEFIs in Member States (MS), but with consistent heterogeneity in procedures, regulations and capacity of systems to collect, analyze and use data, although with great potentialities. Suggestions are posed by authors to promote actions for unifying strategies and policies among MS. [Copyright &y& Elsevier]

The current challenge worldwide is the administration of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. Considering that the COVID-19 vaccination represents the best possibility to resolve this pandemic, this systematic review aims to clarify the major aspects of fatal adverse effects related to COVID-19 vaccines, with the goal of advancing our knowledge, supporting decisions, or suggesting changes in policies at local, regional, and global levels. Moreover, this review aims to provide key recommendations to improve awareness of vaccine safety. All studies published up to 2 December 2021 were searched using the following keywords: "COVID-19 Vaccine", "SARS-CoV-2 Vaccine", "COVID-19 Vaccination", "SARS-CoV-2 Vaccination", and "Autopsy" or "Post-mortem". We included 17 papers published with fatal cases with post-mortem investigations. A total of 38 cases were analyzed: 22 cases were related to ChAdOx1 nCoV-19 administration, 10 cases to BNT162b2, 4 cases to mRNA-1273, and 2 cases to Ad26.COV2.S. Based on these data, autopsy is very useful to define the main characteristics of the so-called vaccine-induced immune thrombotic thrombocytopenia (VITT) after ChAdOx1 nCoV-19 vaccination: recurrent findings were intracranial hemorrhage and diffused microthrombi located in multiple areas. Moreover, it is fundamental to provide evidence about myocarditis related to the BNT162B2 vaccine. Finally, based on the discussed data, we suggest several key recommendations to improve awareness of vaccine safety. [ABSTRACT FROM AUTHOR]