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Infection, Genetics and Evolution :... Dec 2014Rotavirus infections continue to be the leading cause of severe diarrhea in young Korean children. Rotavirus data acquired from uninterrupted surveillance studies... (Meta-Analysis)
Meta-Analysis Review
Rotavirus infections continue to be the leading cause of severe diarrhea in young Korean children. Rotavirus data acquired from uninterrupted surveillance studies between 1989 and 2009 in South Korea were analyzed to better understand the genetic diversity and evolution. The relationship between rotaviruses and the currently licensed rotavirus vaccine viruses was also examined. The most prevalent rotavirus strains, with genotype G1P[8], followed by G3P[8], G4P[6], and G2P[4], accounted for approximately 76.7% of the total identified strains, and more recently, rotavirus G9P[8] has significance increased to be the fifth most common genotype. Phylogenetic analyses underscored the heterogeneity between viral populations within each genotype, with different lineages and sub-lineages. Although the currently licensed rotavirus vaccines are effective, safe, and economical, additional data from rotavirus monitoring is necessary to evaluate the efficacy of these vaccines for their sustained use in South Korea. The present study provides comprehensive and up-to-date information regarding the epidemiology, genetic diversity, and evolution of the circulating rotaviruses in South Korea.
Topics: Amino Acid Sequence; Antigens, Viral; Capsid Proteins; Genetic Variation; Genome, Viral; Genotype; Humans; Molecular Sequence Data; Phylogeny; Population Surveillance; RNA, Viral; Recombination, Genetic; Republic of Korea; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Sequence Alignment; Sequence Analysis, DNA; Serogroup
PubMed: 25218045
DOI: 10.1016/j.meegid.2014.08.020 -
Vaccine Mar 2022Rotavirus remains a leading cause of diarrhoeal morbidity and mortality in young children and rotavirus vaccines are critical for reducing global disease burden. This...
Rotavirus remains a leading cause of diarrhoeal morbidity and mortality in young children and rotavirus vaccines are critical for reducing global disease burden. This report addresses the performance of rotavirus vaccines in countries with high child mortality. We performed a sensitivity analysis as part of a systematic review on rotavirus vaccines to inform development of World Health Organization vaccine recommendations. The efficacy of four prequalified vaccines against severe rotavirus gastroenteritis was similar across high mortality settings in Asia and Africa. Within the first year following vaccination, vaccine efficacy for the four vaccines ranged from 48% to 57% while in the second year, efficacy ranged from 29% to 54%. The four vaccines showed no increase in intussusception risk in these settings. All four vaccines appear to prevent significant numbers of severe rotavirus gastroenteritis episodes with no measurable increase in intussusception risk in high mortality settings in Africa and Asia.
Topics: Africa; Child; Child Mortality; Child, Preschool; Humans; Infant; Rotavirus; Rotavirus Infections; Rotavirus Vaccines
PubMed: 35184924
DOI: 10.1016/j.vaccine.2022.02.003 -
Human Vaccines & Immunotherapeutics 2019There are knowledge gaps regarding evidence-based research on the burden of vaccine-preventable diseases among human immunodeficiency virus (HIV)-infected and... (Meta-Analysis)
Meta-Analysis
There are knowledge gaps regarding evidence-based research on the burden of vaccine-preventable diseases among human immunodeficiency virus (HIV)-infected and HIV-exposed children aged <18 years in sub-Saharan Africa. It is therefore essential to determine the trend and burden of vaccine-preventable diseases. We completed a systematic review and meta-analysis to identify the incidence, prevalence and case-fatality rates (CFR) attributed to various vaccine-preventable diseases among HIV-infected and HIV-exposed children in sub-Saharan Africa. The trends in the prevalence of vaccine-preventable diseases among HIV-infected and HIV-exposed children were also determined. Nine studies on tuberculosis (TB) were pooled to give an overall incidence rate estimate of 60 (95% confidence interval [CI] 30-70) per 1,000 child-years. The incidence of pneumococcal infections varied between 109-1509 per 100,000 while pertussis was between 2.9 and 3.7 per 1000 child-year. Twenty-two TB prevalence studies reported an estimated prevalence of 16%. Fifteen prevalence studies on hepatitis B infection were pooled together with an estimated prevalence of 5%. The pooled prevalence for pneumococcal infections was 2% while rotavirus diarrhoea reported a prevalence of 13%. Twenty-nine studies on TB were pooled to give an overall CFR estimate of 17% while pneumococcal infections in HIV-infected and exposed children were pooled together with a resultant rate of 15%. Some of the vaccine-preventable diseases still have high incidences, prevalence and CFR among HIV-infected and HIV-exposed children. There is also a dearth of research data on the burden of several vaccine-preventable diseases among HIV-infected and exposed children and a need for more studies in this area.
Topics: Adolescent; Africa South of the Sahara; Child; Child, Preschool; Cost of Illness; HIV Infections; Humans; Incidence; Infant; Pneumococcal Infections; Prevalence; Tuberculosis; Vaccine-Preventable Diseases; Whooping Cough
PubMed: 30945963
DOI: 10.1080/21645515.2019.1599676 -
Vaccine Jul 2013Countries in Latin America were among the first developing countries to introduce new vaccines, particularly rotavirus (RV) and pneumococcal conjugate vaccines (PCVs),... (Observational Study)
Observational Study Review
BACKGROUND
Countries in Latin America were among the first developing countries to introduce new vaccines, particularly rotavirus (RV) and pneumococcal conjugate vaccines (PCVs), into their national immunization schedules. Experiences and lessons learned from these countries are valuable to donors, immunization partners, and policy makers in other countries wishing to make informed decisions on vaccine introduction.
OBJECTIVES
In order to enhance knowledge and promote understanding of the process of new vaccine introduction in the Latin American Region, with particular focus on RV and PCV, we conducted a systematic qualitative assessment. We evaluated the decision-making process, documented the structure in place, and reviewed key factors pertaining to new vaccine introduction. These include country morbidity and mortality data available prior to vaccine introduction, funding sources and mechanisms for vaccine introduction, challenges of implementation, and assessment of vaccine impact.
METHODS
From March 2010 to April 2011, we evaluated a subset of countries that had introduced RV and/or PCV in the past five years through interviews with key informants at the country level and through a systematic review of published data, gray literature, official technical documents, and country-specific health indicators. Countries evaluated were Bolivia, Brazil, Nicaragua, Peru, and Venezuela.
RESULTS
In all countries, the potential of new vaccines to reduce mortality, as established by Millennium Development Goal 4, was an important consideration leading to vaccine introduction. Several factors-the availability of funds, the existence of sufficient evidence for vaccine introduction, and the feasibility of sustainable financing-were identified as crucial components of the decision-making process in the countries evaluated.
CONCLUSIONS
The decision making process regarding new vaccine introduction in the countries evaluated does not follow a systematic approach. Nonetheless, existing evidence on efficacy, potential impact, and cost-effectiveness of vaccine introduction, even if not local data, was important in the decision making process for vaccine introduction.
Topics: Bolivia; Brazil; Cost of Illness; Cost-Benefit Analysis; Decision Making, Organizational; Documentation; Health Policy; Humans; Immunization Programs; Nicaragua; Pan American Health Organization; Peru; Pneumococcal Vaccines; Public Health Surveillance; Rotavirus Vaccines; Vaccines, Conjugate; Venezuela
PubMed: 23777684
DOI: 10.1016/j.vaccine.2013.05.032 -
Clinical Infectious Diseases : An... Jan 2016Norovirus and rotavirus are prominent enteric viruses responsible for severe acute gastroenteritis disease burden around the world. Both viruses recognize and bind to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Norovirus and rotavirus are prominent enteric viruses responsible for severe acute gastroenteritis disease burden around the world. Both viruses recognize and bind to histo-blood group antigens, which are expressed by the fucosyltransferase 2 (FUT2) gene. Individuals with a functional FUT2 gene are termed "secretors." FUT2 polymorphisms may influence viral binding patterns and, therefore, may influence host susceptibility to infection by these viruses.
METHODS
We performed a systematic review of the published literature on this topic. Data were abstracted and compiled for descriptive analyses and metaanalyses. We estimated pooled odds ratios (ORs) for infection using random-effects models.
RESULTS
We found that secretors were 9.9 times (95% confidence interval [CI], 3.9-24.8) as likely to be infected with genogroup II.4 noroviruses and 2.2 times as likely to be infected with genogroup II non-4 noroviruses (95% CI, 1.2-4.2) compared with nonsecretors. Secretors were also 26.6 times more susceptible to infections from P[8]-type rotaviruses compared with nonsecretors (95% CI, 8.3-85.0).
CONCLUSIONS
Our analyses indicate that host genetic susceptibility to norovirus and rotavirus infection may be strain specific. As strain distribution and the proportion of genetic phenotypes vary in different countries, future studies should focus on differences in susceptibility among various ethnicities. Knowledge of innate susceptibility to rotavirus and norovirus can lead to improved understanding of both vaccine performance and individual risk of disease.
Topics: Caliciviridae Infections; Fucosyltransferases; Genetic Predisposition to Disease; Humans; Norovirus; Rotavirus; Rotavirus Infections; Galactoside 2-alpha-L-fucosyltransferase
PubMed: 26508510
DOI: 10.1093/cid/civ873 -
Infectious Diseases of Poverty Dec 2023Non-National Immunization Program (NIP) vaccines have played an important role in controlling vaccine-preventable diseases (VPDs) in China. However, these vaccines are... (Review)
Review
BACKGROUND
Non-National Immunization Program (NIP) vaccines have played an important role in controlling vaccine-preventable diseases (VPDs) in China. However, these vaccines are paid out of pocket and there is room to increase their coverage. We focused on four selected non-NIP vaccines in this study, namely Haemophilus influenzae type b (Hib) vaccine, human papillomavirus (HPV) vaccine, pneumococcal conjugate vaccine (PCV), and rotavirus vaccine. We aimed to conduct a scoping review of their vaccination rates and the major barriers faced by health systems, providers, and caregivers to increase coverage.
METHODS
We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR). We searched five English databases (PubMed, Web of Science, EMBASE, Scopus, and WHO IRIS) and four Chinese databases using the search strategy developed by the study team. Two independent reviewers screened, selected studies, and examined their quality. We summarized the non-NIP vaccine coverage data by vaccine and applied the 5A framework (Access, Affordability, Acceptance, Awareness, Activation) to chart and analyze barriers to increasing coverage.
RESULTS
A total of 28 articles were included in the analysis (nine pertaining to vaccine coverage, and another 19 reporting challenges of increasing uptake). Among the four selected vaccines, coverage for the Hib vaccine was the highest (54.9-55.9% for 1 dose or more from two meta-analyses) in 2016, while the coverage of the other three vaccines was lower than 30%. Eight of the nine included articles mentioned the regional disparity of coverage, which was lower in under-developing regions. For example, the three-dose Hib vaccination rate in eastern provinces was 38.1%, whereas the rate in central and western provinces was 34.3% and 26.2%, respectively in 2017. Within the 5A framework, acceptance, awareness, and affordability stood out as the most prominent themes. Among the 12 identified sub-themes, high prices, low vaccine awareness, concerns about vaccine safety and efficacy were the most cited barriers to increasing the uptake.
CONCLUSIONS
There is an urgent need to increase coverage of non-NIP vaccines and reduce disparities in access to these vaccines across regions. Concerted efforts from the government, the public, and society are required to tackle the barriers and challenges identified in this study, both on the demand and supply side, to ensure everybody has equal access to life-saving vaccines in China. Particularly, the government should take a prudent approach to gradually incorporate non-NIP vaccines into the NIP step by step, and make a prioritizing strategy based on key factors such as disease burden, financial resources, and market readiness, with special attention to high-risk populations and underdeveloped regions.
Topics: Humans; Vaccines; Vaccination; Immunization Programs; China; Cost of Illness
PubMed: 38062480
DOI: 10.1186/s40249-023-01150-8 -
Vaccine Jan 2021Canada's National Advisory Committee on Immunization (NACI) provides guidance on the use of vaccines in Canada. To support the expansion of its mandate to include... (Review)
Review
BACKGROUND
Canada's National Advisory Committee on Immunization (NACI) provides guidance on the use of vaccines in Canada. To support the expansion of its mandate to include considerations for vaccine acceptability when making recommendations, the NACI Secretariat developed a matrix of factors that influence acceptability. To inform and validate the matrix, we systematically reviewed evidence for factors that influence vaccine acceptability, and for interventions aimed at improving acceptability.
METHODS
On 10-11 October 2018 we searched four bibliographic databases, the Theses Canada Portal, and ClinicalTrials.gov. Two reviewers agreed on the included studies. From each study, we extracted information about the participants, intervention or exposure, comparator, and relevant outcomes. Due to heterogeneity in the reported factors and acceptability indicators we synthesized the findings narratively. We appraised the certainty of evidence using GRADE. For each vaccine-preventable disease we populated a matrix of factors for which there was evidence of an influence on acceptability.
RESULTS
One hundred studies (>1 million participants) contributed data relevant to the public, 16 (6191 participants) to healthcare providers, and three (84 participants) to policymakers. There were 43 intervention studies (~2 million participants). Across vaccines, we identified low certainty evidence for 70 factors relevant to the general population, 56 to high-risk groups, and 30 to healthcare providers. The perceived safety and importance of the vaccine, vaccination history, and receiving a recommendation from a healthcare provider were common influential factors. We found low certainty evidence that reminders for childhood vaccines and policies or delivery models for rotavirus vaccines could improve uptake and coverage. Evidence for other interventions was of very low certainty.
CONCLUSIONS
The NACI vaccine acceptability matrix is useful for categorizing acceptability factors for the general public. Reminder systems may improve the uptake of childhood vaccines. Policies that make the rotavirus vaccine universally available and easily accessible may improve coverage.
FUNDING
This systematic review was completed under contract to the Public Health Agency of Canada, Contract #4600001536.
Topics: Canada; Child; Humans; Immunization; Reminder Systems; Rotavirus Vaccines; Vaccination
PubMed: 33257103
DOI: 10.1016/j.vaccine.2020.10.038 -
Clinical Infectious Diseases : An... Sep 2017Two rotavirus vaccines, Rotarix (RV1) and RotaTeq (RV5), were licensed for global use in 2006. A systematic review of 48 peer- reviewed articles with postlicensure data... (Review)
Review
Two rotavirus vaccines, Rotarix (RV1) and RotaTeq (RV5), were licensed for global use in 2006. A systematic review of 48 peer- reviewed articles with postlicensure data from 24 countries showed a median RV1 vaccine effectiveness (VE) of 84%, 75%, and 57% in countries with low, medium, and high child mortality, respectively, and RV5 VE of 90% and 45% in countries with low and high child mortality, respectively. A partial vaccine series provided considerable protection, but not to the same level as a full series. VE tended to decline in the second year of life, particularly in medium- and high-mortality settings, and tended to be greater against more severe rotavirus disease. Postlicensure data from countries across geographic regions and with different child mortality levels demonstrate that under routine use, both RV1 and RV5 are effective against rotavirus disease, supporting the World Health Organization recommendation that all countries introduce rotavirus vaccine into their national immunization program.
Topics: Child; Child, Preschool; Developing Countries; Humans; Infant; Infant, Newborn; Rotavirus Infections; Rotavirus Vaccines; Vaccination; Vaccines, Attenuated
PubMed: 28444323
DOI: 10.1093/cid/cix369 -
Journal of Public Health Research Apr 2013Diarrhoeal illness is a leading cause of child mortality and morbidity worldwide. There are no precise or current estimates of the types and prevalence of pathogens... (Review)
Review
Diarrhoeal illness is a leading cause of child mortality and morbidity worldwide. There are no precise or current estimates of the types and prevalence of pathogens associated with diarrheal illnesses in developed and developing settings. This systematic review assessed data from 60 studies published in the English language from five developing regions and developed countries worldwide to provide regional estimates of enteric pathogens affecting children. The random-effect method was used to establish the weighted average prevalence of pathogens in adults and children for each region. Significantly more pathogens were reported by studies from developing regions compared with Organisation for Economic Co-operation and Development countries (P<0.016). The identification rates of pathogens from community based and hospital based studies were similar (58.5% and 58.1% respectively, P<0.619). The overall detection of enteric pathogens in developing countries was higher in adults (74.8%; 95% CI 63.1-83.8%) compared with children (56.7%; 95% CI 53.0-60.4%) (P<0.001). Rotavirus was the most frequently detected pathogen in all regions with the highest rate, 24.8% (95% CI 18.0-33.1%), detected in the developed countries. This systematic review is the first to provide an estimate of the prevalence of enteric pathogens associated with diarrhoeal illnesses in adults and children in developed and developing settings. While pathogen detection rate is greater in developing regions the consistently high prevalence of rotavirus in both developed and developing settings underscores the urgent need for access to rotavirus vaccines. Increased travel between developing and developed countries increases disease risk, and hence developed countries have a vested interest in supporting vaccine accessibility in developing settings.
PubMed: 25170480
DOI: 10.4081/jphr.2013.e9 -
Wellcome Open Research 2020Randomized controlled trials of licensed oral rotavirus group A (RVA) vaccines, indicated lower efficacy in developing countries compared to developed countries. We...
Randomized controlled trials of licensed oral rotavirus group A (RVA) vaccines, indicated lower efficacy in developing countries compared to developed countries. We investigated the pooled effectiveness of Rotarix in Africa in 2019, a decade since progressive introduction began in 2009. A systematic search was conducted in PubMed to identify studies that investigated the effectiveness of routine RVA vaccination in an African country between 2009 and 2019. A meta-analysis was undertaken to estimate pooled effectiveness of the full-dose versus partial-dose of Rotarix (RV1) vaccine and in different age groups. Pooled odds ratios were estimated using random effects model and the risk of bias assessed using Newcastle-Ottawa scale. The quality of the evidence was assessed using GRADE. By December 2019, 39 (72%) countries in Africa had introduced RVA vaccination, of which 34 were using RV1. Thirteen eligible studies from eight countries were included in meta-analysis for vaccine effectiveness (VE) of RVA by vaccine dosage (full or partial) and age categories. Pooled RV1 VE against RVA associated hospitalizations was 44% (95% confidence interval (CI) 28-57%) for partial dose versus 58% (95% CI 50-65%) for full dose. VE was 61% (95% CI 50-69%), 55% (95% CI 32-71%), 56% (95% CI 43-67%), and 61% (95% CI 42-73%) for children aged <12 months, 12-23 months, <24 months and 12-59 months, respectively. RV1 vaccine use has resulted in a significant reduction in severe diarrhoea in African children and its VE is close to the efficacy findings observed in clinical trials. RV1 VE point estimate was higher for children who received full dose than those who received partial dose, and its protection lasted beyond the first year of life.
PubMed: 33215049
DOI: 10.12688/wellcomeopenres.16174.2