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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 -
Viruses Feb 2022Cellular immunity against rotavirus in children is incompletely understood. This review describes the current understanding of T-cell immunity to rotavirus in children.... (Review)
Review
Cellular immunity against rotavirus in children is incompletely understood. This review describes the current understanding of T-cell immunity to rotavirus in children. A systematic literature search was conducted in Embase, MEDLINE, Web of Science, and Global Health databases using a combination of "t-cell", "rotavirus" and "child" keywords to extract data from relevant articles published from January 1973 to March 2020. Only seventeen articles were identified. Rotavirus-specific T-cell immunity in children develops and broadens reactivity with increasing age. Whilst occurring in close association with antibody responses, T-cell responses are more transient but can occur in absence of detectable antibody responses. Rotavirus-induced T-cell immunity is largely of the gut homing phenotype and predominantly involves Th1 and cytotoxic subsets that may be influenced by IL-10 Tregs. However, rotavirus-specific T-cell responses in children are generally of low frequencies in peripheral blood and are limited in comparison to other infecting pathogens and in adults. The available research reviewed here characterizes the T-cell immune response in children. There is a need for further research investigating the protective associations of rotavirus-specific T-cell responses against infection or vaccination and the standardization of rotavirus-specific T-cells assays in children.
Topics: Humans; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; T-Lymphocytes; Vaccination
PubMed: 35336866
DOI: 10.3390/v14030459 -
Vaccine Apr 2015Prior to the introduction of rotavirus vaccines in 2006, rotavirus was the leading cause of severe gastroenteritis among European children <5 years of age. We conducted... (Review)
Review
Prior to the introduction of rotavirus vaccines in 2006, rotavirus was the leading cause of severe gastroenteritis among European children <5 years of age. We conducted a systematic review of the published literature to examine the effectiveness and impact of rotavirus vaccines in Europe following the first eight years of routine use. Four publication databases were searched, yielding 276 unique citations from February 1st, 2006 to July 31st, 2014. Twenty four studies on effectiveness (n=9) and impact (n=15) met the inclusion criteria. Across Europe, vaccine effectiveness against rotavirus-related healthcare utilisation ranged from 68% to 98%, consistent with efficacy data from clinical trials. Reductions in rotavirus hospitalisations ranged from 65% to 84%, consistent with findings from post-marketing studies from the US and Latin America. We confirm the significant public health benefit of rotavirus vaccination in Europe and provide further evidence to support implementation of universal rotavirus vaccination in all European countries.
Topics: Child; Child, Preschool; Europe; Gastroenteritis; Hospitalization; Humans; Latin America; Male; Product Surveillance, Postmarketing; Rotavirus Infections; Rotavirus Vaccines; Time Factors; United States; Vaccination; Vaccines, Attenuated
PubMed: 25795258
DOI: 10.1016/j.vaccine.2015.03.016 -
Human Vaccines & Immunotherapeutics Nov 2020This study is aimed to review the published evidence on safety, immunogenicity, and efficacy of rotavirus vaccines when co-administered with meningococcal vaccines in...
This study is aimed to review the published evidence on safety, immunogenicity, and efficacy of rotavirus vaccines when co-administered with meningococcal vaccines in infants. A systematic literature search was performed in four databases containing peer-reviewed articles and conference abstracts. In total, twelve articles were included in the review; 11 provided information on safety and five on the immunogenicity of rotavirus vaccines following co-administration. No paper was found on efficacy. Additional routine vaccines were administered in all studies. The safety analysis was mainly focused on fever, vomiting, diarrhea, intussusception, and changes in eating habits. Overall, safety profiles and immune responses associated with rotavirus vaccination were comparable between infants co-administered with rotavirus and meningococcal vaccines and infants receiving rotavirus vaccines without meningococcal vaccines. Although data are limited, co-administration of rotavirus and meningococcal vaccines does not appear to interfere with the safety or immunogenicity of rotavirus vaccines.
Topics: Antibodies, Bacterial; Humans; Infant; Meningococcal Vaccines; Rotavirus Vaccines; Vaccination
PubMed: 32298219
DOI: 10.1080/21645515.2020.1739485 -
The Lancet. Infectious Diseases Feb 2019Oral vaccines underperform in low-income and middle-income countries compared with in high-income countries. Whether interventions can improve oral vaccine performance... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Oral vaccines underperform in low-income and middle-income countries compared with in high-income countries. Whether interventions can improve oral vaccine performance is uncertain.
METHODS
We did a systematic review and meta-analysis of interventions designed to increase oral vaccine efficacy or immunogenicity. We searched Ovid-MEDLINE and Embase for trials published until Oct 23, 2017. Inclusion criteria for meta-analysis were two or more studies per intervention category and available seroconversion data. We did random-effects meta-analyses to produce summary relative risk (RR) estimates. This study is registered with PROSPERO (CRD42017060608).
FINDINGS
Of 2843 studies identified, 87 were eligible for qualitative synthesis and 66 for meta-analysis. 22 different interventions were assessed for oral poliovirus vaccine (OPV), oral rotavirus vaccine (RVV), oral cholera vaccine (OCV), and oral typhoid vaccines. There was generally high heterogeneity. Seroconversion to RVV was significantly increased by delaying the first RVV dose by 4 weeks (RR 1·37, 95% CI 1·16-1·62) and OPV seroconversion was increased with monovalent or bivalent OPV compared with trivalent OPV (RR 1·51, 95% CI 1·20-1·91). There was some evidence that separating RVV and OPV increased RVV seroconversion (RR 1·21, 95% CI 1·00-1·47) and that higher vaccine inoculum improved OCV seroconversion (RR 1·12, 95% CI 1·00-1·26). There was no evidence of effect for anthelmintics, antibiotics, probiotics, zinc, vitamin A, withholding breastfeeding, extra doses, or vaccine buffering.
INTERPRETATION
Most strategies did not improve oral vaccine performance. Delaying RVV and reducing OPV valence should be considered within immunisation programmes to reduce global enteric disease. New strategies to address the gap in oral vaccine efficacy are urgently required.
FUNDING
Wellcome Trust, Bill & Melinda Gates Foundation, UK Medical Research Council, and WHO Polio Research Committee.
Topics: Administration, Oral; Adolescent; Adult; Child; Child, Preschool; Cholera; Cholera Vaccines; Female; Humans; Immunogenicity, Vaccine; Infant; Infant, Newborn; Male; Poliomyelitis; Poliovirus; Poliovirus Vaccine, Oral; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Salmonella typhi; Seroconversion; Treatment Outcome; Typhoid Fever; Typhoid-Paratyphoid Vaccines; Vaccination; Vibrio cholerae; Young Adult
PubMed: 30712836
DOI: 10.1016/S1473-3099(18)30602-9 -
Vaccine Nov 2022Previous studies found conflicting results about the effect of rotavirus (RV) vaccination on seizure hospitalizations in children younger than 5 years old. (Review)
Review
BACKGROUND
Previous studies found conflicting results about the effect of rotavirus (RV) vaccination on seizure hospitalizations in children younger than 5 years old.
OBJECTIVES
To evaluate the evidence of the impact of RV vaccination on the prevention of seizure hospitalizations in children.
METHODS
A systematic review was conducted in the electronic database MEDLINE of all observational studies in children younger than 5 years old published since 2006. Two reviewers performed title/abstract, full-text review, and data extraction.
RESULTS
Thirteen studies met eligibility criteria. Nine studies reported a significant reduction in seizure hospitalizations upon RV vaccine introduction, three studies reported an absence of significant impact, and one study reported a significant rise in seizure hospitalization after the introduction of RV vaccines.
LIMITATIONS
The great variability between study designs, case definitions and potential biases prevent quantifying the impact of RV vaccination against seizure hospitalizations.
CONCLUSIONS
RV vaccination might prevent seizure hospitalizations in children; however, robust, and well-designed studies are needed to better determine the strength of this association.
Topics: Child; Humans; Infant; Child, Preschool; Rotavirus Infections; Rotavirus; Rotavirus Vaccines; Hospitalization; Vaccination; Seizures
PubMed: 36280558
DOI: 10.1016/j.vaccine.2022.09.096 -
The Cochrane Database of Systematic... 2004Rotaviruses cause viral gastroenteritis and result in more deaths from diarrhoea in children under 5 years of age than any other single agent, particularly in low- and... (Review)
Review
BACKGROUND
Rotaviruses cause viral gastroenteritis and result in more deaths from diarrhoea in children under 5 years of age than any other single agent, particularly in low- and middle-income countries.
OBJECTIVES
To assess rotavirus vaccines in relation to preventing rotavirus diarrhoea, death, and adverse events.
SEARCH STRATEGY
We searched the Cochrane Infectious Diseases Group's trial register (October 2003), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2003), MEDLINE (1966 to October 2003), EMBASE (January 1980 to October 2003), LILACS (1982 to October 2003), Biological Abstracts (January 1982 to October 2003), reference lists of articles, and contacted researchers and rotavirus vaccine manufacturers.
SELECTION CRITERIA
Randomized controlled trials comparing rotavirus vaccines to placebo, no intervention, or other rotavirus vaccines in children and adults.
DATA COLLECTION AND ANALYSIS
Two reviewers independently extracted data and assessed trial methodological quality, and contacted trial authors for additional information.
MAIN RESULTS
Sixty-four trials provided information on efficacy and safety of three main types of rotavirus vaccine (bovine, human, and rhesus) for 21,070 children. Different levels of efficacy were demonstrated with different vaccines varying from 22 to 89% to prevent one episode of rotavirus diarrhoea, 11 to 44% to prevent one episode of all-cause diarrhoea, and 43 to 90% to prevent one episode of severe rotavirus diarrhoea. Rhesus vaccine demonstrated a similar efficacy against one episode of rotavirus diarrhoea (37 and 44% respectively), and one episode of all-cause diarrhoea (around 15%) for trials performed in high and middle-income countries. Results on mortality and safety of the vaccines were scarce and incomplete. We noticed important heterogeneity among the pooled studies and were unable to discard a biased estimation of effect.
REVIEWER'S CONCLUSIONS
Current evidence shows that rhesus rotavirus vaccines (particularly RRV-TV) and the human rotavirus vaccine 89-12 are efficacious in preventing diarrhoea caused by rotavirus and all-cause diarrhoea. Evidence about safety, and about mortality or prevention of severe outcomes, is scarce and inconclusive. Bovine rotavirus vaccines were also efficacious, but safety data are not available. Trials of new rotavirus vaccines will hopefully improve the evidence base. Randomized controlled trials should be performed simultaneously in high-, middle-, and low-income countries.
Topics: Adult; Cause of Death; Child; Diarrhea; Humans; Randomized Controlled Trials as Topic; Rotavirus Infections; Rotavirus Vaccines; Vaccines, Attenuated
PubMed: 14973994
DOI: 10.1002/14651858.CD002848.pub2 -
Vaccine Jul 2015Diarrhea is one of the leading causes of death in children under 5, and an estimated 39% of these deaths are attributable to rotavirus. Currently two live, oral... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Diarrhea is one of the leading causes of death in children under 5, and an estimated 39% of these deaths are attributable to rotavirus. Currently two live, oral rotavirus vaccines have been introduced on the market; however, the herd immunity effect associated with rotavirus vaccine has not yet been quantified. The purpose of this meta-analysis was to estimate the herd immunity effects associated with rotavirus vaccines.
METHODS
We performed a systematic literature review of articles published between 2008 and 2014 that measured the impact of rotavirus vaccine on severe gastroenteritis (GE) morbidity or mortality. We assessed the quality of published studies using a standard protocol and conducted meta-analyses to estimate the herd immunity effect in children less than one year of age across all years presented in the studies. We conducted these analyses separately for studies reporting a rotavirus-specific GE outcome and those reporting an all-cause GE outcome.
RESULTS
In studies reporting a rotavirus-specific GE outcome, four of five of which were conducted in the United States, the median herd effect across all study years was 22% [19-25%]. In studies reporting an all-cause GE outcome, all of which were conducted in Latin America, the median herd effect was 24.9% [11-30%].
CONCLUSIONS
There is evidence that rotavirus vaccination confers a herd immunity effect in children under one year of age in the United States and Latin American countries. Given the high variability in vaccine efficacy across regions, more studies are needed to better examine herd immunity effects in high mortality regions.
Topics: Gastroenteritis; Humans; Immunity, Herd; Latin America; Rotavirus Infections; Rotavirus Vaccines; United States
PubMed: 26116250
DOI: 10.1016/j.vaccine.2015.06.064 -
The Lancet. Infectious Diseases Sep 2009Two new rotavirus vaccines have recently been licensed in many countries. However, their efficacy has only been shown against certain serotypes commonly circulating in... (Meta-Analysis)
Meta-Analysis Review
Two new rotavirus vaccines have recently been licensed in many countries. However, their efficacy has only been shown against certain serotypes commonly circulating in Europe, North America, and Latin America, but thought to be globally important. To assess the potential impact of these vaccines in sub-Saharan Africa, where rotavirus mortality is high, knowledge of prevalent types is essential because an effective rotavirus vaccine is needed to protect against prevailing serotypes in the community. We did two systematic reviews and two meta-analyses of the most recent published data on the burden of rotavirus disease in children aged under 5 years and rotavirus serotypes circulating in countries in sub-Saharan Africa. Eligible studies were selected from PubMed/Medline, Cochrane Library, EmBase, LILACS, Academic Search Premier, Biological Abstracts, ISI Web of Science, and the African Index Medicus. Depending on the heterogeneity, DerSimonian-Laird random-effects or fixed-effects models were used for meta-analyses. Geographical variability in rotavirus burden within countries in sub-Saharan Africa is substantial, and most countries lack information on rotavirus epidemiology. We estimated that annual mortality for this region was 243.3 (95% CI 187.6-301.7) deaths per 100,000 under 5 years (ie, a total of 300,000 children die of rotavirus infection in this region each year). The most common G type detected was G1 (34.9%), followed by G2 (9.1%), and G3 (8.6%). The most common P types detected were P[8] (35.5%) and P[6] (27.5%). Accurate information should be collected from surveillance based on standardised methods in these countries to obtain comparable data on the burden of disease and the circulating strains to assess the potential impact of vaccine introduction.
Topics: Africa South of the Sahara; Geography; Humans; Incidence; Rotavirus; Rotavirus Infections; Rotavirus Vaccines; Serotyping
PubMed: 19695493
DOI: 10.1016/S1473-3099(09)70179-3 -
BMC Infectious Diseases May 2024Noroviruses are the second leading cause of death in children under the age of 5 years old. They are responsible for 200 million cases of diarrhoea and 50,000 deaths in... (Meta-Analysis)
Meta-Analysis
Rotavirus vaccines in Africa and Norovirus genetic diversity in children aged 0 to 5 years old: a systematic review and meta-analysis : Rotavirus vaccines in Africa and Norovirus genetic diversity.
Noroviruses are the second leading cause of death in children under the age of 5 years old. They are responsible for 200 million cases of diarrhoea and 50,000 deaths in children through the word, mainly in low-income countries. The objective of this review was to assess how the prevalence and genetic diversity of noroviruses have been affected by the introduction of rotavirus vaccines in Africa. PubMed, Web of Science and Science Direct databases were searched for articles. All included studies were conducted in Africa in children aged 0 to 5 years old with gastroenteritis. STATA version 16.0 software was used to perform the meta-analysis. The method of Dersimonian and Laird, based on the random effects model, was used for the statistical analyses in order to estimate the pooled prevalence's at a 95% confidence interval (CI). Heterogeneity was assessed by Cochran's Q test using the I2 index. The funnel plot was used to assess study publication bias. A total of 521 studies were retrieved from the databases, and 19 were included in the meta-analysis. The pooled norovirus prevalence's for pre- and post-vaccination rotavirus studies were 15% (95 CI, 15-18) and 13% (95 CI, 09-17) respectively. GII was the predominant genogroup, with prevalence of 87.64% and 91.20% respectively for the pre- and post-vaccination studies. GII.4 was the most frequently detected genotype, with rates of 66.84% and 51.24% respectively for the pre- and post-vaccination studies. This meta-analysis indicates that rotavirus vaccination has not resulted in a decrease in norovirus infections in Africa.
Topics: Humans; Rotavirus Vaccines; Infant; Africa; Child, Preschool; Caliciviridae Infections; Norovirus; Rotavirus Infections; Genetic Variation; Gastroenteritis; Infant, Newborn; Prevalence; Rotavirus; Vaccination
PubMed: 38822241
DOI: 10.1186/s12879-024-09434-6