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International Journal of Public Health 2024We aimed to evaluate changes to measles-containing vaccine (MCV) provision and subsequent measles disease cases in low- and lower-middle income countries (LICs, LMICs)...
We aimed to evaluate changes to measles-containing vaccine (MCV) provision and subsequent measles disease cases in low- and lower-middle income countries (LICs, LMICs) in relation to the COVID-19 pandemic. A systematic search was conducted of MEDLINE, OVID EMBASE and PubMed records. Primary quantitative and qualitative research studies published from January 2020 were included if they reported on COVID-19 impact on MCV provision and/or measles outbreak rates within LICs and LMICs. 45 studies were included. The change in MCV1 vaccination coverage in national and international regions ranged -13% to +44.4% from pre-COVID time periods. In local regions, the median MCV1 and overall EPI rate changed by -23.3% and -28.5% respectively. Median MCV2 rate was disproportionally impacted in local areas during COVID-interruption time-periods (-48.2%) with ongoing disruption in early-recovery time-periods (-17.7%). 8.9% of studies reported on vaccination status of confirmed measles cases; from these, 71%-91% had received no MCV dose. MCV vaccination coverage experienced ongoing disruption during the recovery periods after initial COVID-19 disruption. Vaccination in local area datasets notably experienced longer-term disruption compared to nationally reported figures.
Topics: Humans; COVID-19; Developing Countries; Disease Outbreaks; Measles; Measles Vaccine; SARS-CoV-2; Vaccination Coverage
PubMed: 38725903
DOI: 10.3389/ijph.2024.1606997 -
BMC Public Health Nov 2023Due to low vaccination uptake and measles outbreaks across Europe, public health authorities have paid increasing attention to anthroposophic communities. Public media...
BACKGROUND
Due to low vaccination uptake and measles outbreaks across Europe, public health authorities have paid increasing attention to anthroposophic communities. Public media outlets have further described these communities as vaccine refusers or "anti-vaxxers". The aim of this review was to understand the scope of the problem and explore assumptions about vaccination beliefs in anthroposophic communities. For the purpose of this review, we define anthroposophic communities as people following some/certain views more or less loosely connected to the philosophies of anthroposophy. The systematic review addresses three research questions and (1) collates evidence documenting outbreaks linked to anthroposophic communities, (2) literature on vaccination coverage in anthroposophic communities, and (3) lastly describes literature that summarizes theories and factors influencing vaccine decision-making in anthroposophic communities.
METHODS
This is a systematic review using the following databases: Medline, Web of Science, Psycinfo, and CINAHL. Double-blinded article screening was conducted by two researchers. Data was summarized to address the research questions. For the qualitative research question the data was analysed using thematic analysis with the assistance of Nvivo12.0.
RESULTS
There were 12 articles documenting 18 measles outbreaks linked to anthroposophic communities between the years 2000 and 2012. Seven articles describe lower vaccination uptake in anthroposophic communities than in other communities, although one article describes that vaccination coverage in low-income communities with a migrant background was lower than in the anthroposophic community they studied. We found eight articles examining factors and theories influencing vaccine decision making in anthroposophic communities. The qualitative analysis revealed four common themes. Firstly, there was a very broad spectrum of vaccine beliefs among the anthroposophic communities. Secondly, there was a consistent narrative about problems or concerns with vaccines, including toxicity and lack of trust in the system. Thirdly, there was a strong notion of the importance of making individual and well-informed choices as opposed to simply following the masses. Lastly, making vaccine choices different from public health guidelines was highly stigmatized by those outside of the anthroposophic community but also those within the community.
CONCLUSION
Continuing to further knowledge of vaccine beliefs in anthroposophic communities is particularly important in view of increasing measles rates and potential sudden reliance on vaccines for emerging diseases. However, popular assumptions about vaccine beliefs in anthroposophic communities are challenged by the data presented in this systematic review.
Topics: Humans; Anthroposophy; Vaccination Hesitancy; Vaccines; Vaccination; Measles
PubMed: 37957574
DOI: 10.1186/s12889-023-17081-w -
PharmacoEconomics May 2023Economic evaluations of vaccines should accurately represent all relevant economic and health consequences of vaccination, including losses due to adverse events...
Accounting for Adverse Events Following Immunization in Economic Evaluation: Systematic Review of Economic Evaluations of Pediatric Vaccines Against Pneumococcus, Rotavirus, Human Papillomavirus, Meningococcus and Measles-Mumps-Rubella-Varicella.
OBJECTIVES
Economic evaluations of vaccines should accurately represent all relevant economic and health consequences of vaccination, including losses due to adverse events following immunization (AEFI). We investigated to what extent economic evaluations of pediatric vaccines account for AEFI, which methods are used to do so and whether inclusion of AEFI is associated with study characteristics and the vaccine's safety profile.
METHODS
A systematic literature search (MEDLINE, EMBASE, Cochrane Systematic Reviews and Trials, Database of the Centre for Reviews and Dissemination of the University of York, EconPapers, Paediatric Economic Database Evaluation, Tufts New England Cost-Effectiveness Analysis Registry, Tufts New England Global Health CEA, International Network of Agencies for Health Technology Assessment Database) was performed for economic evaluations published between 2014 and 29 April 2021 (date of search) pertaining to the five groups of pediatric vaccines licensed in Europe and the United States since 1998: the human papillomavirus (HPV) vaccines, the meningococcal vaccines (MCV), the measles-mumps-rubella-varicella (MMRV) combination vaccines, the pneumococcal conjugate vaccines (PCV) and the rotavirus vaccines (RV). Rates of accounting for AEFI were calculated, stratified by study characteristics (e.g., region, publication year, journal impact factor, level of industry involvement) and triangulated with the vaccine's safety profile (Advisory Committee on Immunization Practices [ACIP] recommendations and information on safety-related product label changes). The studies accounting for AEFI were analyzed in terms of the methods used to account for both cost and effect implications of AEFI.
RESULTS
We identified 112 economic evaluations, of which 28 (25%) accounted for AEFI. This proportion was significantly higher for MMRV (80%, four out of five evaluations), MCV (61%, 11 out of 18 evaluations) and RV (60%, nine out of 15 evaluations) compared to HPV (6%, three out of 53 evaluations) and PCV (5%, one out of 21 evaluations). No other study characteristics were associated with a study's likelihood of accounting for AEFI. Vaccines for which AEFI were more frequently accounted for also had a higher frequency of label changes and a higher level of attention to AEFI in ACIP recommendations. Nine studies accounted for both the cost and health implications of AEFI, 18 studies considered only costs and one only health outcomes. While the cost impact was usually estimated based on routine billing data, the adverse health impact of AEFI was usually estimated based on assumptions.
DISCUSSION
Although (mild) AEFI were demonstrated for all five studied vaccines, only a quarter of reviewed studies accounted for these, mostly in an incomplete and inaccurate manner. We provide guidance on which methods to use to better quantify the impact of AEFI on both costs and health outcomes. Policymakers should be aware that the impact of AEFI on cost-effectiveness is likely to be underestimated in the majority of economic evaluations.
Topics: Child; Humans; Chickenpox; Cost-Benefit Analysis; Streptococcus pneumoniae; Human Papillomavirus Viruses; Rotavirus; Neisseria meningitidis; Mumps; Papillomavirus Infections; Vaccination; Immunization; Measles; Rotavirus Vaccines; Rubella
PubMed: 36809673
DOI: 10.1007/s40273-023-01252-z -
The Journal of Infectious Diseases Jul 2011Measles control may be more challenging in regions with a high prevalence of HIV infection. HIV-infected children are likely to derive particular benefit from measles... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Measles control may be more challenging in regions with a high prevalence of HIV infection. HIV-infected children are likely to derive particular benefit from measles vaccines because of an increased risk of severe illness. However, HIV infection can impair vaccine effectiveness and may increase the risk of serious adverse events after receipt of live vaccines. We conducted a systematic review to assess the safety and immunogenicity of measles vaccine in HIV-infected children.
METHODS
The authors searched 8 databases through 12 February 2009 and reference lists. Study selection and data extraction were conducted in duplicate. Meta-analysis was conducted when appropriate.
RESULTS
Thirty-nine studies published from 1987 through 2008 were included. In 19 studies with information about measles vaccine safety, more than half reported no serious adverse events. Among HIV-infected children, 59% (95% confidence intervals [CI], 46-71%) were seropositive after receiving standard-titer measles vaccine at 6 months (1 study), comparable to the proportion of seropositive HIV-infected children vaccinated at 9 (8 studies) and 12 months (10 studies). Among HIV-exposed but uninfected and HIV-unexposed children, the proportion of seropositive children increased with increasing age at vaccination. Fewer HIV-infected children were protected after vaccination at 12 months than HIV-exposed but uninfected children (relative risk, 0.61; 95% CI, .50-.73).
CONCLUSIONS
Measles vaccines appear to be safe in HIV-infected children, but the evidence is limited. When the burden of measles is high, measles vaccination at 6 months of age is likely to benefit children of HIV-infected women, regardless of the child's HIV infection status.
Topics: Child; HIV Infections; Humans; Measles; Measles Vaccine; Vaccination
PubMed: 21666158
DOI: 10.1093/infdis/jir071 -
Vaccine Jan 2020In settings where measles has been eliminated, vaccine-derived immunity may in theory wane more rapidly due to a lack of immune boosting by circulating measles virus. We...
BACKGROUND
In settings where measles has been eliminated, vaccine-derived immunity may in theory wane more rapidly due to a lack of immune boosting by circulating measles virus. We aimed to assess whether measles vaccine effectiveness (VE) waned over time, and if so, whether differentially in measles-eliminated and measles-endemic settings.
METHODS
We performed a systematic literature review of studies that reported VE and time since vaccination with measles-containing vaccine (MCV). We extracted information on case definition (clinical symptoms and/or laboratory diagnosis), method of vaccination status ascertainment (medical record or vaccine registry), as well as any biases which may have arisen from cold chain issues and a lack of an age at first dose of MCV. We then used linear regression to evaluate VE as a function of age at first dose of MCV and time since MCV.
RESULTS
After screening 14,782 citations, we identified three full-text articles from measles-eliminated settings and 33 articles from measles-endemic settings. In elimination settings, two-dose VE estimates increased as age at first dose of MCV increased and decreased as time since MCV increased; however, the small number of studies available limited interpretation. In measles-endemic settings, one-dose VE increased by 1.5% (95% CI 0.5, 2.5) for every month increase in age at first dose of MCV. We found no evidence of waning VE in endemic settings.
CONCLUSIONS
The paucity of data from measles-eliminated settings indicates that additional studies and approaches (such as studies using proxies including laboratory correlates of protection) are needed to answer the question of whether VE in measles-eliminated settings wanes. Age at first dose of MCV was the most important factor in determining VE. More VE studies need to be conducted in elimination settings, and standards should be developed for information collected and reported in such studies.
Topics: Age Factors; Humans; Immunization Schedule; Infant; Measles; Measles Vaccine; Measles virus; Randomized Controlled Trials as Topic; Treatment Outcome; Vaccination
PubMed: 31732326
DOI: 10.1016/j.vaccine.2019.10.090 -
Archives of Pediatrics & Adolescent... Jul 2003To systematically review the evidence for and against the existence of an association between autistic spectrum disorder (ASD) and the measles, mumps, and rubella (MMR)... (Review)
Review
OBJECTIVE
To systematically review the evidence for and against the existence of an association between autistic spectrum disorder (ASD) and the measles, mumps, and rubella (MMR) vaccine.
STUDY DESIGN
We conducted a systematic review of the medical literature to identify all controlled epidemiological articles examining for an association between ASD and the MMR vaccine. We extracted data from the articles on the characteristics and objectives of the study as well as evidence of an association.
RESULTS
Twelve articles met the inclusion criteria. One study found no difference in the rates of ASD and the MMR vaccine in children who were vaccinated and those who were not. Six studies examined for evidence of an increase in ASD associated with an increase in the MMR vaccine coverage, none of which showed evidence of an association. Four studies examined if a variant form of ASD was associated with the MMR vaccine, none of which showed evidence of an association. Eight studies attempted to determine if there was a temporal association between developing ASD and receiving the MMR vaccine. Of these, 1 study identified an increase in parental concern in the 6-month period following vaccination with MMR in one of its analyses. The results of all other studies showed no association between ASD and the MMR vaccine.
CONCLUSIONS
The current literature does not suggest an association between ASD and the MMR vaccine; however, limited epidemiological evidence exists to rule out a link between a rare variant form of ASD and the MMR vaccine. Given the real risks of not vaccinating and that the risks and existence of variant ASD remain theoretical, current policies should continue to advocate the use of the MMR vaccine.
Topics: Autistic Disorder; Child; Humans; Measles-Mumps-Rubella Vaccine; Research Design
PubMed: 12860782
DOI: 10.1001/archpedi.157.7.628 -
BMJ (Clinical Research Ed.) Oct 2016To evaluate the effects on non-specific and all cause mortality, in children under 5, of Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP), and... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To evaluate the effects on non-specific and all cause mortality, in children under 5, of Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP), and standard titre measles containing vaccines (MCV); to examine internal validity of the studies; and to examine any modifying effects of sex, age, vaccine sequence, and co-administration of vitamin A.
DESIGN
Systematic review, including assessment of risk of bias, and meta-analyses of similar studies.
STUDY ELIGIBILITY CRITERIA
Clinical trials, cohort studies, and case-control studies of the effects on mortality of BCG, whole cell DTP, and standard titre MCV in children under 5.
DATA SOURCES
Searches of Medline, Embase, Global Index Medicus, and the WHO International Clinical Trials Registry Platform, supplemented by contact with experts in the field. To avoid overlap in children studied across the included articles, findings from non-overlapping birth cohorts were identified.
RESULTS
Results from 34 birth cohorts were identified. Most evidence was from observational studies, with some from short term clinical trials. Most studies reported on all cause (rather than non-specific) mortality. Receipt of BCG vaccine was associated with a reduction in all cause mortality: the average relative risks were 0.70 (95% confidence interval 0.49 to 1.01) from five clinical trials and 0.47 (0.32 to 0.69) from nine observational studies at high risk of bias. Receipt of DTP (almost always with oral polio vaccine) was associated with a possible increase in all cause mortality on average (relative risk 1.38, 0.92 to 2.08) from 10 studies at high risk of bias; this effect seemed stronger in girls than in boys. Receipt of standard titre MCV was associated with a reduction in all cause mortality (relative risks 0.74 (0.51 to 1.07) from four clinical trials and 0.51 (0.42 to 0.63) from 18 observational studies at high risk of bias); this effect seemed stronger in girls than in boys. Seven observational studies, assessed as being at high risk of bias, have compared sequences of vaccines; results of a subset of these suggest that administering DTP with or after MCV may be associated with higher mortality than administering it before MCV.
CONCLUSIONS
Evidence suggests that receipt of BCG and MCV reduce overall mortality by more than would be expected through their effects on the diseases they prevent, and receipt of DTP may be associated with an increase in all cause mortality. Although efforts should be made to ensure that all children are immunised on schedule with BCG, DTP, and MCV, randomised trials are needed to compare the effects of different sequences.
Topics: BCG Vaccine; Child; Child, Preschool; Diphtheria; Diphtheria-Tetanus-Pertussis Vaccine; Evidence-Based Medicine; Female; Humans; Immunization Schedule; Infant; Male; Measles; Measles Vaccine; Mortality; Tetanus; Tuberculosis; United Kingdom; Vaccination; Whooping Cough
PubMed: 27737834
DOI: 10.1136/bmj.i5170 -
Vaccine Mar 2014Although immune response to vaccines can be influenced by several parameters, human genetic variations are thought to strongly influence the variability in vaccine... (Meta-Analysis)
Meta-Analysis Review
Although immune response to vaccines can be influenced by several parameters, human genetic variations are thought to strongly influence the variability in vaccine responsiveness. Systematic reviews and meta-analyses are needed to clarify the genetic contribution to this variability, which may affect the efficacy of existing vaccines. We performed a systematic literature search to identify all studies describing the associations of allelic variants or single nucleotide polymorphisms in immune response genes with vaccine responses until July 2013. The studies fulfilling inclusion criteria were meta-analyzed. Thirteen studies (11,686 subjects) evaluated the associations of human leukocyte antigen (HLA) and other immunity gene variations with the responses to single vaccines, including MMR-II (measles and rubella virus), HepB (hepatitis virus), influenza virus, and MenC (serogroup C meningococcus) vaccines. Seven HLA genetic variants were included in the meta-analyses. The pooled ORs showed that DRB1*07 (2.46 [95% CI=1.60-3.77]; P for heterogeneity=0.117; I(2)=49.1%), DQA1*02:01 (2.21 [95% CI=1.22-4.00]; P for heterogeneity=0.995; I(2)=0.0%), DQB1*02:01 (2.03 [95% CI=1.35-3.07]; P for heterogeneity=0.449; I(2)=0.0%), and DQB1*03:03 (3.31 [95% CI=1.12-9.78]; P for heterogeneity=0.188; I(2)=42.4%) were associated with a significant decrease of antibody responses to MMR-II, HepB, and influenza vaccines. The pooled ORs showed that DRB1*13 (0.52 [95% CI=0.32-0.84]; P for heterogeneity=0.001; I(2)=85.1%) and DRB1*13:01 (0.19 [95% CI=0.06-0.58]; P for heterogeneity=0.367; I(2)=0.0%) were associated with a significant increase of antibody responses to the above vaccines. While our findings reinforce the concept that individuals with a particular HLA allelic composition are more likely to respond efficiently to vaccines, future studies should be encouraged to further elucidate the link between genetic variation and variability of the human immune response to vaccines.
Topics: Antibody Formation; HLA-DQ Antigens; HLA-DRB1 Chains; Humans; Polymorphism, Single Nucleotide; Vaccines
PubMed: 24513009
DOI: 10.1016/j.vaccine.2014.01.057 -
The Lancet. Infectious Diseases Nov 2019Vaccinating infants with a first dose of measles-containing vaccine (MCV1) before 9 months of age in high-risk settings has the potential to reduce measles-related... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vaccinating infants with a first dose of measles-containing vaccine (MCV1) before 9 months of age in high-risk settings has the potential to reduce measles-related morbidity and mortality. However, there is concern that early vaccination might blunt the immune response to subsequent measles vaccine doses. We systematically reviewed the available evidence on the effect of MCV1 administration to infants younger than 9 months on their immune responses to subsequent MCV doses.
METHODS
For this systematic review and meta-analysis, we searched for randomised and quasi-randomised controlled trials, outbreak investigations, and cohort and case-control studies without restriction on publication dates, in which MCV1 was administered to infants younger than 9 months. We did the literature search on June 2, 2015, and updated it on Jan 14, 2019. We included studies reporting data on strength or duration of humoral and cellular immune responses, and on vaccine efficacy or vaccine effectiveness after two-dose or three-dose MCV schedules. Our outcome measures were proportion of seropositive infants, geometric mean titre, vaccine efficacy, vaccine effectiveness, antibody avidity index, and T-cell stimulation index. We used random-effects meta-analysis to derive pooled estimates of the outcomes, where appropriate. We assessed the methodological quality of included studies using Grading of Recommendation Assessment, Development and Evaluation (GRADE) guidelines.
FINDINGS
Our search retrieved 1156 records and 85 were excluded due to duplication. 1071 records were screened for eligibility, of which 351 were eligible for full-text screening and 21 were eligible for inclusion in the review. From 13 studies, the pooled proportion of infants seropositive after two MCV doses, with MCV1 administered before 9 months of age, was 98% (95% CI 96-99; I=79·8%, p<0·0001), which was not significantly different from seropositivity after a two-dose MCV schedule starting later (p=0·087). Only one of four studies found geometric mean titres after MCV2 administration to be significantly lower when MCV1 was administered before 9 months of age than at 9 months of age or later. There was insufficient evidence to determine an effect of age at MCV1 administration on antibody avidity. The pooled vaccine effectiveness estimate derived from two studies of a two-dose MCV schedule with MCV1 vaccination before 9 months of age was 95% (95% CI 89-100; I=12·6%, p=0·29). Seven studies reporting on measles virus-specific cellular immune responses found that T-cell responses and T-cell memory were sustained, irrespective of the age of MCV1 administration. Overall, the quality of evidence was moderate to very low.
INTERPRETATION
Our findings suggest that administering MCV1 to infants younger than 9 months followed by additional MCV doses results in high seropositivity, vaccine effectiveness, and T-cell responses, which are independent of the age at MCV1, supporting the vaccination of very young infants in high-risk settings. However, we also found some evidence that MCV1 administered to infants younger than 9 months resulted in lower antibody titres after one or two subsequent doses of MCV than when measles vaccination is started at age 9 months or older. The clinical and public-health relevance of this immunity blunting effect are uncertain.
FUNDING
WHO.
Topics: Age Factors; Antibodies, Viral; Female; Humans; Immunity, Cellular; Immunity, Humoral; Immunization Schedule; Infant; Male; Measles; Measles Vaccine; Measles virus; T-Lymphocytes; Treatment Outcome
PubMed: 31548081
DOI: 10.1016/S1473-3099(19)30396-2 -
Vaccine Oct 2017The risk of post-vaccination adverse events (AEs) is a primary public health concern. Among the AEs, pain is a significant source of anxiety for both children and their... (Review)
Review
PURPOSE
The risk of post-vaccination adverse events (AEs) is a primary public health concern. Among the AEs, pain is a significant source of anxiety for both children and their parents. This review describes and assesses the intensity of pain experienced by children post-vaccination with widely used Measles-Mumps-Rubella (MMR) vaccines.
METHODS
A systematic literature search was conducted in Pubmed, Embase and Cochrane to identify publications describing immediate pain at injection site (primary objective) or pain within days (secondary objective) after 2 specific MMR vaccines. Immediate pain ('acute pain' according to the Brighton Collaboration case definition) was defined as pain occurring at the time or within 5min of injection.
RESULTS
Four studies, which compared the intensity of immediate injection site pain experienced by children after MMR vaccination, were identified. Various pain assessment tools and methods were used to quantify the intensity of pain, including the median difference in Visual Analog Scale scores between vaccine groups. All four studies showed significantly less immediate pain caused by Priorix (GSK Vaccines) compared with M-M-R II (Merck & Co., Inc.).
CONCLUSIONS
To our knowledge, this review summarizes for the first time the available scientific evidence on the intensity of pain following different MMR vaccines. It highlights that MMR vaccines can differ in terms of immediate pain. Further research may be needed to better understand the underlying reason for this observation. In this context, it is very important to understand which physicochemical properties are most relevant for the immediate pain profile of a vaccine to thereby support the development of vaccines with the best possible immediate pain profile.
Topics: Humans; Measles-Mumps-Rubella Vaccine; Pain; Vaccination; Vaccines, Combined
PubMed: 28893478
DOI: 10.1016/j.vaccine.2017.08.068