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Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and middle-income countries is needed. NDV-HXP-S is an inactivated egg-based Newcastle disease virus (NDV) vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Wuhan-Hu-1. The spike protein was stabilized and incorporated into NDV virions by removing the polybasic furin cleavage site, introducing the transmembrane domain and cytoplasmic tail of the fusion protein of NDV, and introducing six prolines for stabilization in the prefusion state. Vaccine production and clinical development was initiated in Vietnam, Thailand, and Brazil. Here the interim results from the first stage of the randomized, dose-escalation, observer-blind, placebo-controlled, phase 1/2 trial conducted at the Hanoi Medical University (Vietnam) are presented. Healthy adults aged 18-59 years, non-pregnant, and with self-reported negative history for SARS-CoV-2 infection were eligible. Participants were randomized to receive one of five treatments by intramuscular injection twice, 28 days apart: 1 μg +/-CpG1018 (a toll-like receptor 9 agonist), 3 μg alone, 10 μg alone, or placebo. Participants and personnel assessing outcomes were masked to treatment. The primary outcomes were solicited adverse events (AEs) during 7 days and subject-reported AEs during 28 days after each vaccination. Investigators further reviewed subject-reported AEs. Secondary outcomes were immunogenicity measures (anti-spike immunoglobulin G [IgG] and pseudotyped virus neutralization). This interim analysis assessed safety 56 days after first vaccination (day 57) in treatment-exposed individuals and immunogenicity through 14 days after second vaccination (day 43) per protocol. Between March 15 and April 23, 2021, 224 individuals were screened and 120 were enrolled (25 per group for active vaccination and 20 for placebo). All subjects received two doses. The most common solicited AEs among those receiving active vaccine or placebo were all predominantly mild and included injection site pain or tenderness (ClinicalTrials.govNCT04830800.

Giardia spp. is detected frequently in humans and animals. Although many studies have been conducted on the epidemiology of giardiasis, there is a scarcity of information on the genetic diversity and the dynamics of transmission of Giardia spp. in Vietnam. The zoonotic potential of Giardia spp. remains elusive. The objective of this study was to determine the genetic diversity of Giardia spp. in both humans and livestock to assess the existence of a route of infection between livestock and humans. Our goal was to assess the role animals play in the epidemiology of human infection in northern Vietnam. In Hien Khanh commune in northern Vietnam, 311 households with 1508 residents were randomly selected for a diarrheal cohort study. Of these, 2120 human diarrheal samples were collected from 1508 residents in 2014 and 2017. Of these, non-diarrheal samples were cross-sectionally collected from 471 residents. At the same site, livestock samples from buffalo, dairy and beef cattle, pigs, and dogs were collected. All stool samples were examined for Giardia spp. by Direct Immunofluorescence Assay (DFA) using fluorescent microscope. DNA extraction, PCR analysis of the 3 genes (bg, gdh, tpi), and sequencing analysis were continuously carried out. A total of 23 animal stool samples, 8 human non-diarrheal samples, and 36 human diarrheal samples were Giardia spp. were positive by PCR using the bg and gdh genes. Giardia spp. assemblage AII and E were detected in both animal samples and human samples in this study site. The detection of assemblage E in human stool samples suggests the first human case report in Vietnam. We assume that the unexpected human infection of all Giardia assemblages including A, B, and E may be due to an environment contaminated with animal and human feces in this village.

Giardia spp. is detected frequently in humans and animals. Although many studies have been conducted on the epidemiology of giardiasis, there is a scarcity of information on the genetic diversity and the dynamics of transmission of Giardia spp. in Vietnam. The zoonotic potential of Giardia spp. remains elusive. The objective of this study was to determine the genetic diversity of Giardia spp. in both humans and livestock to assess the existence of a route of infection between livestock and humans. Our goal was to assess the role animals play in the epidemiology of human infection in northern Vietnam. In Hien Khanh commune in northern Vietnam, 311 households with 1508 residents were randomly selected for a diarrheal cohort study. Of these, 2120 human diarrheal samples were collected from 1508 residents in 2014 and 2017. Of these, non-diarrheal samples were cross-sectionally collected from 471 residents. At the same site, livestock samples from buffalo, dairy and beef cattle, pigs, and dogs were collected. All stool samples were examined for Giardia spp. by Direct Immunofluorescence Assay (DFA) using fluorescent microscope. DNA extraction, PCR analysis of the 3 genes (bg, gdh, tpi), and sequencing analysis were continuously carried out. A total of 23 animal stool samples, 8 human non-diarrheal samples, and 36 human diarrheal samples were Giardia spp. were positive by PCR using the bg and gdh genes. Giardia spp. assemblage AII and E were detected in both animal samples and human samples in this study site. The detection of assemblage E in human stool samples suggests the first human case report in Vietnam. We assume that the unexpected human infection of all Giardia assemblages including A, B, and E may be due to an environment contaminated with animal and human feces in this village., Graphical abstract Unlabelled Image, Highlights • Giardia spp. assemblage A and E have been detected in buffalo, cattle and pigs, as well as in humans, while assemblage B appeared only in humans. • This was the first report of assemblage E in humans in Vietnam. • Zoonotic transmission of assemblage AII and E could not be excluded in our study site. • In addition to the ‘animal-to-human’ route, there potentially might be transmission routes from ‘humans-to-humans’ and/or ‘humans-to-animals’ in this study site. • The novel genotype belonging to assemblage AIII has been isolated only in buffalo.

Purpose: Viet Nam currently relies on a manual paper-based system to track and monitor 28 major infectious diseases. This inefficient system takes 2 or more months to complete. Method: We designed and pilot tested the use of text messaging to report certain infectious disease symptoms in rural areas of northern Viet Nam. The project was divided into three 6-month phases carried out in two provinces. The current analysis focuses on the implementation of a two-way feedback system between Phases II and III, which aims at (1) evaluating whether this system improves efficiency by determining the number of correctly (vs. incorrectly) formatted text messages; (2) assessing this system's influence on accuracy by comparing text messages with their respective official paper-based documented forms; and (3) determining whether the amount of information required to report through text messages influences the efficiency and accuracy of the text messages. Results: Between Phases II and III, results revealed a significant improvement in correctly formatted texts in comparison to incorrectly formatted texts. As the number of fields required to report increased, the number of correctly formatted texts (efficiency) as well as the number of matched text messages (accuracy) decreased. Conclusion: Our research demonstrates that an automated error bidirectional feedback system can significantly improve both the efficiency and accuracy of a Short Message Service-based method for disease surveillance. Also, our data may suggest that two-way communication has better engaged health care staff to follow reporting protocols as well as to maintain accuracy from their clinic's own data.

Human rabies deaths are preventable through prompt administration of postexposure prophylaxis (PEP) with rabies immune globulin and rabies vaccine after exposure to a rabid animal (1); there are no known contraindications to receiving PEP (1,2). Despite widespread availability of PEP in Vietnam, in 2015 the Ministry of Health (MoH) received reports of pregnant and breastfeeding women with clinically diagnosed rabies. MoH investigated factors associated with these rabies cases. MoH found that, during 2015-2016, among 169 cases reported in Vietnam, two probable cases of rabies were reported in breastfeeding mothers and four in pregnant women, all of whom had been bitten by dogs. All six patients died. Three of the four pregnant women had cesarean deliveries. One of the three newborns died from complications believed to be unrelated to rabies; the fourth pregnant woman contracted rabies too early in pregnancy for the fetus to be viable. Two of the patients sought care from a medical provider or traditional healer; however, none sought PEP after being bitten. In each case, families reported the patient's fear of risk to the fetus or breastfed child as the primary barrier to receiving PEP. These findings highlight the need for public health messaging about the safety and effectiveness of PEP in preventing rabies among all persons with exposures, including pregnant and breastfeeding women.

INTRODUCTION:Along with the exponential growth of technology, the use of mobile devices in health, or mHealth, has been quickly becoming a viable practice to strengthen health systems, especially in low-resource settings. Nevertheless, the majority of mHealth interventions are pilot efforts which mostly lack robust design and evidence about the use of mHealth in public health. This study assessed the use of a bi-directional Short Message Service (SMS) in disease surveillance in Vietnam and aimed to bring evidence in improving engagement of health staff as well as the quality of reporting.METHODS:Eighty health staff from fourty communes of Hoa Binh and Hung Yen provinces were trained and participated in two 6-month pilots: one with one-way, and one with a bi-directional SMS system for assisting in error screening, and reminder and feedback provision to report two diseases: influenza and diarrhea using cell phones. After each examination and checking-in onto the paper logbook, participants reported the case by texting an SMS to a designated number and made notes of successfully reported cases. A central data repository server was set up to collect SMS reports, and aggregate reported patient data. Engagement of health staff and quality of the reporting work were assessed by the evaluation of the qualitative questionnaires, and the comparison of the texted SMS reports to the patient logbooks.RESULTS:With the use of a two-way versus one-way SMS system, participants were 4.6 times more likely (95 percent Confidence Interval, CI 3.93-5.44, p< .001) to send correctly formatted text reports, and 3.4 times more likely (95 percent CI 2.72-4.33, p< .001) to have precise information in their texted messages. Results also revealed that while their position, age, or gender of participants did not statistically influence the results, ethnicity and management roles did.CONCLUSIONS:The study showed that the use of a bi-directional SMS-based reporting system both significantly improved participants engagement in the reporting protocol, and greatly enhanced their reporting quality. The study demonstrated that robust evidence of a practical utilization of SMS in a disease reporting system to replace the traditional paper-based one has great potential for a scale-up and national-wide implementation.

The interplay between nasopharyngeal bacterial carriage, viral coinfection, and lower respiratory tract infections (LRTIs) is poorly understood. We explored this association in Vietnamese children aged less than 5 years.A hospital-based case-control study of pediatric LRTIs was conducted in Nha Trang, Vietnam. A total of 550 hospitalized children (274 radiologically confirmed pneumonia [RCP] and 276 other LRTIs) were enrolled and 350 healthy controls were randomly selected from the community. Polymerase chain reaction-based methods were used to measure bacterial loads of Streptococcus pneumoniae (SP), Haemophilus influenzae, and Moraxella catarrhalis and to detect 13 respiratory viruses and bacterial serotypes in nasopharyngeal samples of study participants.The median nasopharyngeal bacterial load of SP was substantially higher in children with RCP compared with healthy controls or children with other LRTIs (P0.001). SP load was 15-fold higher in pneumonia children with viral coinfection compared with those children without viral coinfection (1.4 x 10⁷/mL vs. 9.1 x 10⁵/mL; P 0.0001). SP load was over 200-fold higher in serotypeable SP compared with nontypeable SP (2.5 x 10⁶/mL vs. 1 x 10⁴/mL; P0.0001). These associations were independent of potential confounders in multiple regression models. No clear association was found between nasopharyngeal load of Haemophilus influenzae or Moraxella catarrhalis and viral coinfection in either RCP or other LRTIs groups.An increased load of SP in the nasopharynx was associated with RCP, viral coinfection, and presence of pneumococcal capsule.

Hospitalized Vietnamese children with acute respiratory infection were investigated for 13 viral pathogens using multiplex-polymerase chain reaction. We enrolled 958 children of whom 659 (69%) had documented viral infection: rhinovirus (28%), respiratory syncytial virus (23%), influenza virus (15%), adenovirus (5%), human metapneumo virus (4.5%), parainfluenza virus (5%), and bocavirus (2%). These Vietnamese children had a range of respiratory viruses which underscores the need for enhanced acute respiratory infection surveillance in tropical developing countries., The Pediatric infectious disease journal, 29(1), pp.75-77; 2010

Comprehensive population-based data on the role of respiratory viruses in the development of lower respiratory tract infections (LRTIs) remain unclear. We investigated the incidence and effect of single and multiple infections with respiratory viruses on the risk of LRTIs in Vietnam. Population-based prospective surveillance and a case-control study of hospitalised paediatric patients with acute respiratory infection (ARI) were conducted from April 2007 through to March 2010. Healthy controls were randomly recruited from the same community. Nasopharyngeal samples were collected and tested for 13 respiratory viruses using multiplex PCRs. 1992 hospitalised ARI episodes, including 397 (19.9%) with LRTIs, were enrolled. Incidence of hospitalised LRTIs among children aged

Health information systems to monitor vaccine safety are used in industrialized countries to detect adverse medical events related to vaccinations or to prove the safety of vaccines. There are no such information systems in the developing world, but they are urgently needed. A large linked database for the monitoring of vaccine-related adverse events has been established in Khanh Hoa province, Viet Nam. Data collected during the first 2 years of surveillance, a period which included a mass measles vaccination campaign, were used to evaluate the system. For this purpose the discharge diagnoses of individuals admitted to polyclinics and hospitals were coded according to the International Classification of Diseases (ICD)-10 guidelines and linked in a dynamic population database with vaccination histories. A case-series analysis was applied to the cohort of children vaccinated during the mass measles vaccination campaign. The study recorded 107,022 immunizations in a catchment area with a population of 357,458 and confirmed vaccine coverage of 87% or higher for completed routine childhood vaccinations. The measles vaccination campaign immunized at least 86% of the targeted children aged 9 months to 10 years. No medical event was detected significantly more frequently during the 14 days after measles vaccination than before it. The experience in Viet Nam confirmed the safety of a measles vaccination campaign and shows that it is feasible to establish health information systems such as a large linked database which can provide reliable data in a developing country for a modest increase in use of resources.

Rotavirus A (RVA) strains, a leading cause of severe gastroenteritis in children worldwide, commonly possess the Wa or DS-1 genotype constellations. During a hospital-based study conducted in Hanoi, Vietnam, in the 2012-2013 rotavirus season, G1P[8] strains with a virtually identical short RNA migration pattern were detected in 20 (14%) of 141 rotavirus-positive samples. Two representatives of these strains were shown by whole-genome sequencing to be double-gene reassortants possessing the genotype constellation of G1-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2. Sequencing and a database search revealed that these Vietnamese G1P[8] double-gene reassortant strains shared an immediate ancestor with a locally circulating G2P[4] strain in all of the inner-capsid and non-structural protein genes, whereas they were more closely related in the VP7 and VP4 genes to a Chinese G1P[8] strain and a Chinese G3P[8] strain, respectively, than to locally circulating G1P[8] strains. Despite the marked similarity between Japanese and Thai G1P[8] double-gene reassortant strains, phylogenetic analysis suggested that the Vietnamese and Japanese/Thai G1P[8] double-gene reassortant strains originated from independent reassortment events. Clinically, children infected with Vietnamese G1P[8] double-gene reassortant strains experienced severe diarrhoea, but it was not more severe than that in children infected with ordinary G1P[8] strains. In conclusion, Vietnamese G1P[8] double-gene reassortant strains originated from a locally circulating G2P[4] strain and caused severe diarrhoea, but there was no evidence of increased virulence. Electronic supplementary material The online version of this article (doi:10.1007/s00705-016-3155-6) contains supplementary material, which is available to authorized users.