Safety and immunogenicity of an inactivated recombinant Newcastle disease virus vaccine expressing SARS-CoV-2 spike: A randomised, comparator-controlled, phase 2 trial.

Production of affordable coronavirus disease 2019 (COVID-19) vaccines in low- and lower-middle-income countries is needed. NDV-HXP-S is an inactivated egg-based recombinant Newcastle disease virus vaccine expressing the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A public sector manufacturer in Vietnam assessed the immunogenicity of NDV-HXP-S (COVIVAC) relative to an authorized vaccine.

Prevalence and Characterization of Gastroenteritis Viruses among Hospitalized Children during a Pilot Rotavirus Vaccine Introduction in Vietnam.

Rotavirus (RV), norovirus (NoV), sapovirus (SaV), and human astrovirus (HAstV) are the most common viral causes of gastroenteritis in children worldwide. From 2016 to 2021, we conducted a cross-sectional descriptive study to determine the prevalence of these viruses in hospitalized children under five years old in Nam Dinh and Thua Thien Hue provinces in Vietnam during the pilot introduction of the RV vaccine, Rotavin-M1 (POLYVAC, Hanoi, Vietnam). We randomly selected 2317/6718 (34%) acute diarrheal samples from children <5 years of age enrolled at seven sentinel hospitals from December 2016 to May 2021; this period included one year surveillance pre-vaccination from December 2016 to November 2017.

Risk Factors Associated with Diarrheal Episodes in an Agricultural Community in Nam Dinh Province, Vietnam: A Prospective Cohort Study.

In Vietnam, data on the risk factors for diarrhea at the community level remain sparse. This study aimed to provide an overview of diarrheal diseases in an agricultural community in Vietnam, targeting all age groups. Specifically, we investigated the incidence of diarrheal disease at the community level and described the potential risk factors associated with diarrheal diseases.

Safety and immunogenicity of two formulations of rotavirus vaccine in Vietnamese infants.

Background And Aims: ROTAVIN-M1® (licensed, frozen vaccine) and ROTAVIN (second-generation, liquid candidate vaccine) are two rotavirus vaccine formulations developed from a live attenuated G1P8 (KH0118) strain by Center for Research and Production of Vaccines and Biologicals (POLYVAC), Vietnam. This study compared the safety and immunogenicity of these two formulations.

Methods: A Phase 3, randomized, partially double-blinded, active-controlled study was conducted in healthy infants aged 60-91 days in Vietnam.

Immunogenicity and safety of a nine-valent human papillomavirus vaccine in Vietnamese males and females (9 to 26 years of age): an open-label, phase 3 trial.

This open-label, single-center, Phase 3 study (NCT03546842) assessed the immunogenicity and safety of the nine-valent human papillomavirus (9vHPV; HPV6/11/16/18/31/33/45/52/58) vaccine in Vietnamese males and females, with the aim to support 9vHPV vaccine licensure in Vietnam. Participants aged 9-26 years received three 9vHPV vaccine doses (Day 1, Month 2, Month 6). Serum samples were obtained on Day 1 (pre-vaccination) and at Month 7 (one month post-Dose 3) for the measurement of anti-HPV antibodies.

Molecular epidemiology of Cryptosporidium spp. in an agricultural area of northern Vietnam: A community survey.

The purpose of this study was to investigate the occurrence of Cryptosporidium infection and the potential for transmission of Cryptosporidium spp. between animals and humans in northern Vietnam. A total of 2715 samples (2120 human diarrheal samples, 471 human non-diarrheal samples, and 124 animal stool samples) were collected through our community survey in an agricultural area.

Safety of a quadrivalent influenza vaccine in Vietnamese healthy subjects aged 6 months and older.

Quadrivalent influenza vaccines (QIVs) provide protection against the two influenza A viruses (H1N1 and H3N2) and both co-circulating influenza B lineages. QIVs have been found safe, immunogenic, and efficacious in several phase III clinical trials. Here we assess the safety of QIV after vaccination in Vietnamese infants, children, and adults.

Author Correction: Exposure to paternal tobacco smoking increased child hospitalization for lower respiratory infections but not for other diseases in Vietnam.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A Phase 2/3 double blinded, randomized, placebo-controlled study in healthy adult participants in Vietnam to examine the safety and immunogenicity of an inactivated whole virion, alum adjuvanted, A(H5N1) influenza vaccine (IVACFLU-A/H5N1).

Background: A global shortfall of vaccines for avian influenza A(H5N1) would occur, especially in low- and-middle income countries, if a pandemic were to occur. To address this issue, development of a pre-pandemic influenza vaccine was initiated in 2012, leveraging a recently established influenza vaccine manufacturing capacity in Vietnam.

Methods: This was a Phase 2/3, double-blinded, randomized, placebo-controlled study to test the safety and immunogenicity of IVACFLU-A/H5N1 vaccine in healthy adults.

Effect of Vitamin D supplementation to reduce respiratory infections in children and adolescents in Vietnam: A randomized controlled trial.

Background: It is uncertain whether vitamin D can reduce respiratory infection.

Objective: To determine whether vitamin D supplementation reduces influenza and other upper viral respiratory tract infections.

Methods: A total of 1300 healthy children and adolescents between the ages of 3 and 17 years were randomized to vitamin D (14 000 U weekly) or placebo for 8 months in Vietnam.

Seasonality of respiratory viruses causing hospitalizations for acute respiratory infections in children in Nha Trang, Vietnam.

Background: Acute respiratory infections (ARIs) are the most common causes of death in children under 5 years of age. While the etiology of most pneumonia and ARI episodes is undiagnosed, a broad range of ARI-causing viruses circulate widely in South East Asia. However, the patterns and drivers of the seasonal transmission dynamics are largely unknown.

Geographical and temporal patterns of rabies post exposure prophylaxis (PEP) incidence in humans in the Mekong River Delta and Southeast Central Coast regions in Vietnam from 2005 to 2015.

Background: In Vietnam, rabies has been a notifiable disease for more than 40 years. Over the last five years, on average, more than 350,000 people per year have been bitten by dogs and cats while more than 80 human deaths have been reported yearly. No studies have been conducted to evaluate the geographical and temporal patterns of rabies in humans in Vietnam.

Valine/isoleucine variants drive selective pressure in the VP1 sequence of EV-A71 enteroviruses.

Background: In 2011-2012, Northern Vietnam experienced its first large scale hand foot and mouth disease (HFMD) epidemic. In 2011, a major HFMD epidemic was also reported in South Vietnam with fatal cases. This 2011-2012 outbreak was the first one to occur in North Vietnam providing grounds to study the etiology, origin and dynamic of the disease.

Exposure to paternal tobacco smoking increased child hospitalization for lower respiratory infections but not for other diseases in Vietnam.

Exposure to environmental tobacco smoke (ETS) is an important modifiable risk factor for child hospitalization, although its contribution is not well documented in countries where ETS due to maternal tobacco smoking is negligible. We conducted a birth cohort study of 1999 neonates between May 2009 and May 2010 in Nha Trang, Vietnam, to evaluate paternal tobacco smoking as a risk factor for infectious and non-infectious diseases. Hospitalizations during a 24-month observation period were identified using hospital records.

Randomized safety and immunogenicity trial of a seasonal trivalent inactivated split virion influenza vaccine (IVACFLU-S) in healthy young Vietnamese adults.

Background: Under the auspices of the World Health Organization (WHO) Global Action Plan, PATH supported evaluation of a trivalent, seasonal inactivated influenza vaccine candidate produced by the Institute of Vaccines and Medical Biologicals (IVAC), a Vietnamese manufacturer.

Methods: In 2015, 60 healthy adult subjects 18-45years of age were enrolled in a Phase 1, single center, double blind, randomized, placebo-controlled study conducted at a district health center in Thai Binh Province, Vietnam. The study evaluated the overall safety and immunogenicity of a seasonal, trivalent inactivated split virion influenza vaccine.

Population-Based Incidence Rates of First-Ever Stroke in Central Vietnam.

Introduction: Stroke incidence data with methodologically acceptable design in Southeast Asia countries is limited. This study aimed to determine incidence of age-, sex- and subtype-specific first-ever stroke (FES) in Vietnam.

Methods: We conducted a hospital-based retrospective study, targeting all stroke cases hospitalized at a solo-provider hospital in our study site of Nha Trang from January 2009 to December 2011 with International Classification of Diseases, 10th revision (ICD-10) codes I60-69.

Seasonality of absolute humidity explains seasonality of influenza-like illness in Vietnam.

Background: Experimental and ecological studies have shown the role of climatic factors in driving the epidemiology of influenza. In particular, low absolute humidity (AH) has been shown to increase influenza virus transmissibility and has been identified to explain the onset of epidemics in temperate regions. Here, we aim to study the potential climatic drivers of influenza-like illness (ILI) epidemiology in Vietnam, a tropical country characterized by a high diversity of climates.

A Multi-country Study of the Household Willingness-to-Pay for Dengue Vaccines: Household Surveys in Vietnam, Thailand, and Colombia.

Background: The rise in dengue fever cases and the absence of dengue vaccines will likely cause governments to consider various types of effective means for controlling the disease. Given strong public interests in potential dengue vaccines, it is essential to understand the private economic benefits of dengue vaccines for accelerated introduction of vaccines into the public sector program and private markets of high-risk countries.

Methodology/principal Findings: A contingent valuation study for a hypothetical dengue vaccine was administered to 400 households in a multi-country setting: Vietnam, Thailand, and Colombia.

Vaccine safety monitoring systems in developing countries: an example of the Vietnam model.

Only few health intervention programs have been as successful as vaccination programs with respect to preventing morbidity and mortality in developing countries. However, the success of a vaccination program is threatened by rumors and misunderstanding about the risks of vaccines. It is short-sighted to plan the introduction of vaccines into developing countries unless effective vaccine safety monitoring systems are in place.

Oral cholera vaccine development and use in Vietnam.

Anna Lena Lopez and colleagues give an overview of the cholera situation in Vietnam and discuss how an oral cholera vaccine was developed and used as a component of a public health strategy against the disease.

Epidemiology, clinical manifestations, and outcomes of Streptococcus suis infection in humans.

Streptococcus suis, a bacterium that affects pigs, is a neglected pathogen that causes systemic disease in humans. We conducted a systematic review and meta-analysis to summarize global estimates of the epidemiology, clinical characteristics, and outcomes of this zoonosis. We searched main literature databases for all studies through December 2012 using the search term "streptococcus suis.