Mumps, And Rubella Vaccine Coverage Research Articles

Routine vaccination coverage at ages 2 and 7, before, during, and after the COVID-19 pandemic: Results from the STARVAX surveillance system.

A decline in routine vaccination coverage in children has been observed after the onset of the COVID-19 pandemic, but it is unclear whether these declines were sustained over time. This analysis assessed changes in vaccination coverage at ages 2 and 7years for routinely administered vaccinations before, during, and after the COVID-19 pandemic. Vaccination coverage was measured using yearly data from the Standardized Reporting on Vaccination (STARVAX) surveillance system between December 31, 2019, and December 31, 2023. Four provinces (Alberta, Saskatchewan, Manitoba, and New Brunswick) and one territory (Yukon) produced reports from their immunization registries and provided the Public Health Agency of Canada with the numbers of vaccinated 2-year-old and 7-year-old children. Population estimates from Statistics Canada and the Yukon Bureau of Statistics were used as the denominators. There was a decline in vaccination coverage in 2023 compared to 2019. In 2-year-olds, coverage for one dose of the measles, mumps, and rubella (MMR) vaccine and four doses of the diphtheria, tetanus, and acellular pertussis (DTaP) vaccine decreased from 89.5% to 82.5% and from 79.9% to 72.1%, respectively. Among 7-year-olds, DTaP (up-to-date) and MMR (two doses) vaccination coverage decreased from 77.1% to 68.8% and 86.3% to 75.6%, respectively. These declines are of concern and suggest that health care professionals should provide parents with accurate information regarding vaccines and encourage them to have their children vaccinated and keep vaccinations up to date.

39 Impact of the COVID-19 pandemic on routine immunization coverage in Canada: Results from a novel national surveillance system

Abstract Background The COVID-19 pandemic has posed unprecedented challenges to routine immunization programs globally. There is a growing body of evidence highlighting the impact of the pandemic on other routinely administered public health services. Understanding vaccination trends for routinely administered vaccinations during the pandemic is crucial for addressing potential gaps in protection and devising targeted strategies to enhance routine immunization programs. Objectives This study investigates the impact of the pandemic on routine immunization coverage in Canada, focusing on DTaP (Diphtheria, Tetanus, and Pertussis) with at least 4 doses and MMR (Measles, Mumps, and Rubella) with at least 1 dose, among children at age 2. Design/Methods Data were collected from the Routine Childhood Vaccination Coverage Surveillance system (RCVCSS) a novel national surveillance based on standardized detailed reports prepared by participating provinces and territories using data from their immunization registries. This analysis covers the years 2019 to 2022, capturing pre-pandemic, pandemic, and post-pandemic phases with data from 4 reporting provinces and territories (Alberta, Saskatchewan, New Brunswick and Yukon). The primary objective was to assess any changes in vaccination coverage at age 2 for routinely administered immunizations from 2019 to 2022, i.e., before, during and after the COVID-19 pandemic. Results Analysis reveals a decline in routine immunization coverage from 2019 to 2022. DTaP vaccination coverage at age 2 decreased from 82.0% in 2019 to 71.8% in 2022. Likewise, MMR vaccination coverage at two years showed a decline from 90.8% in 2019 to 81.7% in 2022. Similar downward trends in coverage were observed for other sets of antigens vaccinated against at age 2 including Varicella, Rotavirus, Polio, Pneumococcal and Hepatitis B. No major differences were observed when looking at vaccination coverage over time by sex. There were regional variations, with certain jurisdictions experiencing more pronounced declines than others and an increase in coverage in 2022 the post pandemic year. Conclusion There was a sustained decline in DTaP and MMR vaccination coverage at age 2 from 2019 to 2022. Further research is imperative to ascertain whether there has been a catch-up in vaccination coverage and to identify the root causes of the observed declines, so these can be addressed, and targeted interventions can be undertaken to allow coverage level to recover to their pre-pandemic levels.

Municipality-level measles, mumps, and rubella (MMR) vaccine coverage and deprivation in Brazil: A nationwide ecological study, 2006 to 2020.

To better understand the declining rates of routine childhood vaccination in Brazil, we investigated the association between measles, mumps, and rubella (MMR) first dose vaccine coverage and deprivation at the municipality level. Using routinely collected data from 5565 Brazilian municipalities from 2006 to 2020, we investigated the association between municipality-level MMR vaccine first dose coverage (i.e., as a continuous variable and as a percentage of municipalities attaining the 95% target coverage) in relation to quintiles of municipality-level deprivation, measured by the Brazilian Deprivation Index (Índice Brasileiro de Privação, IBP), and geographic regions. From 2006 to 2020, the mean municipality-level MMR vaccine coverage declined across all deprivation quintiles and regions of Brazil, by an average of 1.2% per year. The most deprived quintile of municipalities had higher coverage on average, but also the steepest declines in coverage (i.e., an annual decline of 1.64% versus 0.61% in the least deprived quintile) in the period of 2006-2020, and the largest drop in coverage at the beginning of the COVID-19 pandemic (2019-2020). Across all deprivation quintiles and regions (except for the Southeast region), less than 50% of municipalities in Brazil met the 95% MMR coverage target in 2020.The decrease in MMR first dose vaccine coverage in Brazil is widespread, but steeper declines have been observed in the most deprived municipalities. To promote vaccine equity and prevent future outbreaks, further research is urgently needed to understand the causal mechanisms underlying the observed associations between municipality-level MMR vaccine coverage and deprivation.

State Policy Removing the Personal Belief Exemption for Measles, Mumps, and Rubella (MMR) School Immunization Requirement, Washington State, 2014-2022.

Objectives. To assess the impact of Washington State's 2019 Engrossed House Bill (EHB) 1638-which removed measles, mumps, and rubella (MMR) personal belief exemptions-on MMR vaccine series completion and exemption rates in K-12 students. Methods. We used interrupted time-series analyses to examine changes in MMR vaccine series completion rates before and after EHB 1638 was passed and the χ2 test for differences in exemption rates. Results. EHB 1638 implementation was associated with a 5.4% relative increase in kindergarten MMR vaccine series completion rates (95% confidence interval = 3.8%, 7.1%; P ≤ .001), and results were similar with Oregon as a control state (no change observed in Oregon; P = .68). MMR exemptions overall decreased 41% (from 3.1% in 2018-2019 to 1.8% in 2019-2020; P ≤ .001), and religious exemptions increased 367% (from 0.3% to 1.4%; P ≤ .001). Conclusions. EHB 1638 was associated with an increase in MMR vaccine series completion rates and a decrease in any MMR exemption. However, effects were partially offset by an increase in religious exemption rates. Public Health Implications. Removal of personal belief exemptions for the MMR immunization requirement only may be an effective approach to increase MMR vaccine coverage rates statewide and among underimmunized communities. (Am J Public Health. 2023;113(7):795-804. https://doi.org/10.2105/AJPH.2023.307285).

MMR vaccine coverage and associated factors among overseas-born refugee children resettled in Aotearoa New Zealand: a national retrospective cohort study

Refugee children may be under-immunised against common vaccine-preventable diseases due to a myriad of factors related to their migration journey. This retrospective cohort study explored the rates and determinants of enrolment on the National Immunisation Register (NIR) and measles, mumps and rubella (MMR) coverage among refugee children up to 18 years old who resettled in Aotearoa New Zealand (NZ) from 2006 to 2013. Univariate and multivariable logistic regression were conducted to determine associations. Of the cohort (N=2796), two thirds of the children (69%) were enrolled on the NIR. Among this sub-cohort (n=1926), less than one third (30%) were age-appropriately vaccinated with MMR. MMR coverage was highest among younger children and improved over time. Logistic modelling revealed that visa category, year of arrival, and age group were significant factors that influenced NIR enrolment and MMR vaccine uptake. Those arriving via asylum seeking, family reunification and humanitarian pathways were less likely to be enrolled and vaccinated compared to refugees who entered under the national quota programme. More recent arrivals and younger children were more likely to be enrolled and vaccinated compared to children who arrived in NZ longer ago and were older. Resettled refugee children have suboptimal NIR enrolment and MMR coverage rates which varied significantly by visa category, highlighting the need for immunisation services to better engage with all refugee families. These findings suggest that broad structural factors related to policy and immunisation service delivery may influence the differentials seen. Health Research Council of New Zealand (18/586).

Measles, mumps, and rubella vaccination coverage in children younger than 5 years attending a paediatric emergency department in Manchester, UK: a cross-sectional observational study

BackgroundIn 2019, the UK lost its WHO measles-free status, due to circulating measles virus and suboptimal coverage with the measles, mumps, and rubella (MMR) vaccine. The National Health Service (NHS) schedule recommends MMR vaccines at age 12 and 40 months. In England in 2020–21, MMR coverage did not meet the 95% target for herd immunity. This work is part of a project to develop a vaccination intervention delivered in the paediatric emergency department (PED). The aim of this study was to quantify unmet MMR-related vaccination need among PED attendees. MethodsThis cross-sectional, single-centre observational study collected data on children (aged 1–5 years) attending a large district general PED in Greater Manchester, UK, from Oct 1 to Oct 31, 2021, with data collected on a single occasion. Ethics approval was for an opt-out approach. Vaccination data were extracted from individual electronic summary care records, as part of the primary care record visible within secondary care. Coverage in the study population was compared with data for the northwest of England from the Cover of Vaccination Evaluated Rapidly surveillance scheme for the period April 1, 2020 to March 31, 2021. χ2 tests were used to examine differences in proportions vaccinated. Findings1059 children aged 1–5 years attended the PED in October, 2021, and data for 977 children were included in this study. Among all children, 638 (65·3%) had at least one dose of MMR recorded in their summary care record. The most similar regional comparator was first-dose MMR by the age of 5 years, which was administered in 86 678 (95·2%) of 91 023 children in 2020–21 (p<0·0001). In our cohort, among eligible children older than 40 months (n=339), only 66 (19·5%) had received both MMR doses, compared with regional coverage (by age 5 years) in 79 535 (87·4%) of 91 023 children (p<0·0001). A power calculation showed 577 participants were needed to detect a 5% difference in second-dose MMR. InterpretationChildren younger than 5 years attending the PED had low rates of age-appropriate MMR vaccination coverage, suggesting considerable unmet need in these PED attendees. Other work within this project looks at tetanus coverage and sources of vaccination data. FundingNone.

Does education about local vaccination rates and the importance of herd immunity change US parents’ concern about measles?

It is unclear how broadly aware parents are of the concept of herd immunity and whether parents consider community benefits of vaccination when making decisions about their child’s vaccinations. We aimed to determine whether educating parents about community-level benefits of measles, mumps, and rubella (MMR) vaccination and local vaccination rates would impact concern about their child’s risk of measles and risk of a measles outbreak.We conducted an electronic survey among Minnesota parents of children aged 6–18 years in August 2016. We assessed baseline knowledge of herd immunity, asked participants to estimate MMR vaccination coverage in their county, and asked participants to estimate the minimum coverage needed to prevent measles outbreaks. We then delivered a short, educational intervention via the survey to inform participants about the benefits of herd immunity, the actual MMR vaccination coverage in their county, and that at least 95% MMR vaccination coverage is needed to prevent measles outbreaks. Pre- and post-intervention, participants were asked to report how concerned they were that their child might get measles. We used logistic regression models to assess factors associated with awareness of herd immunity, change in concern about one’s child’s measles risk, and overall concern for a measles outbreak.Among 493 participants, 67.8% were aware of herd immunity at baseline. Post-intervention, 40.2% (n = 198) of parents learned that MMR vaccination rates in their county were higher than they expected. All participants found out that their county MMR rates were lower than the measles herd immunity threshold of 95%. Overall, 27.0% (n = 133) of participants reported an increase in concern that their child might get measles after learning about local vaccination coverage and the coverage needed to achieve herd immunity.We found that our short, educational intervention aimed to increase awareness about herd immunity and local vaccination led to an increase in concern about disease risk among less than a third of parents.

2468. Impact of a Herd Immunity Educational Intervention on Parental Concern About Measles

BackgroundMaintaining high coverage of measles, mumps, and rubella (MMR) vaccination is important for preventing outbreaks and maintaining herd immunity (HI), which benefits both individuals and communities. We aimed to determine whether information about the benefits of HI and local MMR vaccination rates could change a parent’s concern about their child’s risk of contracting measles.MethodsWe conducted a survey at the 2016 Minnesota State Fair among Minnesota residents ≥18 years who had at least one child aged 6–18 years. Participants were asked to choose the correct definition of HI, to estimate the MMR vaccination coverage in their county, and guess the minimum MMR vaccination coverage needed to prevent measles outbreaks. We delivered an educational intervention through the interactive survey informing participants about the benefits of herd immunity, the actual MMR coverage in their county, and that ≥95% coverage is needed to prevent outbreaks. Before and after the educational intervention, participants were asked to report their level of concern about their child contracting measles. We calculated adjusted predicted percentages from logistic regression models to evaluate changes in concern about risk pre- and post-intervention and to assess factors associated with concern about measles.ResultsAmong the 493 participants, 92.7% reported vaccinating their child with MMR, though one third were not familiar with HI. Prior to receiving information, those knowledgeable about HI were significantly more likely to be concerned about their child getting measles (predicted percentage 80.2% [95% CI: 75.7–84.6]) than those who were unfamiliar with HI (predicted percentage 69.8% [95% CI: 62.1–77.5]), P-value for the difference = 0.027. Participants believed that MMR vaccination was, on average, 9.0% [95% CI: 6.9–11.0] lower than the actual coverage in their local area.ConclusionInformation about HI and local vaccination coverage rates did not impact parental concern about their child being at risk for getting measles. Overall, parents learned that local MMR vaccination rates were higher than they had expected.Disclosures All authors: No reported disclosures.

Public Health and Economic Consequences of Vaccine Hesitancy for Measles in the United States

Routine childhood vaccination is declining in some regions of the United States due to vaccine hesitancy, which risks the resurgence of many infectious diseases with public health and economic consequences. There are ongoing policy debates on the state and national level, including legislation around nonmedical (personal-belief) exemptions for childhood vaccination and possibly a special government commission on vaccine safety, which may affect vaccine coverage. To estimate the number of measles cases in US children and the associated economic costs under scenarios of different levels of vaccine hesitancy, using the case example of measles, mumps, and rubella (MMR) vaccination and measles. Publicly available data from the US Centers for Disease Control and Prevention were used to simulate county-level MMR vaccination coverage in children (age 2-11 years) in the United States. A stochastic mathematical model was adapted for infectious disease transmission that estimated a distribution for outbreak size as it relates to vaccine coverage. Economic costs per measles case were obtained from the literature. The predicted effects of increasing the prevalence of vaccine hesitancy as well as the removal of nonmedical exemptions were estimated. The model was calibrated to annual measles cases in US children over recent years, and the model prediction was validated using an independent data set from England and Wales. Annual measles cases in the United States and the associated public sector costs. A 5% decline in MMR vaccine coverage in the United States would result in an estimated 3-fold increase in measles cases for children aged 2 to 11 years nationally every year, with an additional $2.1 million in public sector costs. The numbers would be substantially higher if unvaccinated infants, adolescents, and adult populations were also considered. There was variation around these estimates due to the stochastic elements of measles importation and sensitivity of some model inputs, although the trend was robust. This analysis predicts that even minor reductions in childhood vaccination, driven by vaccine hesitancy (nonmedical and personal belief exemptions), will have substantial public health and economic consequences. The results support an urgent need to address vaccine hesitancy in policy dialogues at the state and national level, with consideration of removing personal belief exemptions of childhood vaccination.

The web and public confidence in MMR vaccination in Italy.

Measles, mumps and rubella (MMR) vaccination coverage in Italy has been decreasing starting from 2012 and, at the present, none of the Italian regions has achieved the goal of 95% coverage target. A decision of the Court of Justice of Rimini in March 2012 that awarded vaccine-injury compensation for a case of autism has been indicated as a probable trigger event leading to a reduction of vaccine confidence in Italy. The aim of the study was to explore the relationship between MMR vaccination coverage to online search trends and social network activity on the topic "autism and MMR vaccine", during the period 2010-2015. A significant inverse correlation was found between MMR vaccination coverage and Internet search activity, tweets and Facebook posts. New media might have played a role in spreading misinformation. Media monitoring could be useful to assess the level of vaccine hesitancy and to plan and target effective information campaigns.

Effectiveness of Early Measles, Mumps, and Rubella Vaccination Among 6-14-Month-Old Infants During an Epidemic in the Netherlands: An Observational Cohort Study.

Routinely, the first measles, mumps, and rubella (MMR) vaccine dose is given at 14 months of age in the Netherlands. However, during a measles epidemic in 2013-2014, MMR vaccination was also offered to 6-14-month-olds in municipalities with <90% MMR vaccination coverage. We studied the effectiveness of the early MMR vaccination schedule. Parents of all infants targeted for early MMR vaccination were asked to participate. When parent(s) suspected measles, their infant's saliva was tested for measles-specific antibodies. The vaccine effectiveness (VE) against laboratory-confirmed and self-reported measles was estimated using Cox regression, with VE calculated as 1 minus the hazard ratio. Three vaccinated and 10 unvaccinated laboratory-confirmed cases occurred over observation times of 106631 and 23769 days, respectively. The unadjusted VE against laboratory-confirmed measles was 94% (95% confidence interval [CI], 79%-98%). After adjustment for religion and sibling's vaccination status, the VE decreased to 71% (-72%-95%). For self-reported measles, the unadjusted and adjusted VE was 67% (40%-82%) and 43% (-12%-71%), respectively. Infants vaccinated between 6 and 14 months of age had a lower risk of measles than unvaccinated infants. However, part of the effect was caused by herd immunity, since vaccinated infants were more likely to be surrounded by other vaccinated individuals.

Public Health and Economic Consequences of Vaccine Hesitancy for Measles in the United States

Importance Routine childhood vaccination is declining in some regions of the United States due to vaccine hesitancy, which risks the resurgence of many infectious diseases with public health and economic consequences. There are ongoing policy debates on the state and national level, including legislation around nonmedical (personal-belief) exemptions for childhood vaccination and possibly a special government commission on vaccine safety, which may affect vaccine coverage. Objective To estimate the number of measles cases in US children and the associated economic costs under scenarios of different levels of vaccine hesitancy, using the case example of measles, mumps, and rubella (MMR) vaccination and measles. Design, Setting, and Participants Publicly available data from the US Centers for Disease Control and Prevention were used to simulate county-level MMR vaccination coverage in children (age 2-11 years) in the United States. A stochastic mathematical model was adapted for infectious disease transmission that estimated a distribution for outbreak size as it relates to vaccine coverage. Economic costs per measles case were obtained from the literature. The predicted effects of increasing the prevalence of vaccine hesitancy as well as the removal of nonmedical exemptions were estimated. The model was calibrated to annual measles cases in US children over recent years, and the model prediction was validated using an independent data set from England and Wales. Main Outcomes and Measures Annual measles cases in the United States and the associated public sector costs. Results A 5% decline in MMR vaccine coverage in the United States would result in an estimated 3-fold increase in measles cases for children aged 2 to 11 years nationally every year, with an additional $2.1 million in public sector costs. The numbers would be substantially higher if unvaccinated infants, adolescents, and adult populations were also considered. There was variation around these estimates due to the stochastic elements of measles importation and sensitivity of some model inputs, although the trend was robust. Conclusions and Relevance This analysis predicts that even minor reductions in childhood vaccination, driven by vaccine hesitancy (nonmedical and personal belief exemptions), will have substantial public health and economic consequences. The results support an urgent need to address vaccine hesitancy in policy dialogues at the state and national level, with consideration of removing personal belief exemptions of childhood vaccination.

Prevalence of anti-rubella, anti-measles and anti-mumps IgG antibodies in neonates and pregnant women in Catalonia (Spain) in 2013: susceptibility to measles increased from 2003 to 2013.

Non-immune neonates and non-immune pregnant women are at risk of developing rubella, measles and mumps infections, including congenital rubella syndrome. We describe the seroepidemiology of measles, mumps and rubella (MMR) in neonates and pregnant women in Catalonia (Spain). Anti-rubella, anti-measles and anti-mumps serum IgG titres were assessed using enzyme-linked immunosorbent assay (ELISA) tests in 353 cord blood samples from neonates of a representative sample of pregnant women obtained in 2013. The prevalence of protective antibody titres in neonates was 96 % for rubella IgG (≥8 IU/ml), 90 % for measles IgG (>300 IU/ml) and 84 % for mumps IgG (>460 EU/ml). Slightly lower prevalences of protective IgG titres, as estimated from the cord blood titres, were found in pregnant women: 95 % for rubella IgG, 89 % for measles IgG and 81 % for mumps IgG. The anti-measles and anti-mumps IgG titres and the prevalences of protective IgG titres against measles and mumps increased significantly (p < 0.001) with maternal age. The prevalence of protective anti-measles IgG titres decreased by 7 % [odds ratio (OR) = 0.15, p < 0.001), the prevalence of protective anti-rubella IgG titres increased by 3 % (OR = 1.80, p < 0.05) and the MMR vaccination coverage (during childhood) in pregnant women increased by 54 % (OR = 2.09, p < 0.001) from 2003 to 2013. We recommend to develop an MMR prevention programme in women of childbearing age based on mass MMR vaccination or MMR screening and vaccination of susceptible women to increase immunity levels against MMR.

Seroprevalence of measles, mumps and rubella among children in American Samoa, 2011, and progress towards West Pacific Region goals of elimination

IntroductionIn line with the global goals for measles elimination, countries in the West Pacific Region (WPR) have set a goal to eliminate measles by 2012. Due to its contagiousness, high population immunity is needed for achieving and documenting measles elimination. We assessed population immunity to measles, mumps and rubella among first grade children in American Samoa (AS) through a seroprevalance study. MethodsUsing commercial indirect enzyme-linked immunosorbant IgG assays (Wampole Laboratories, Cranbury, NJ) we determined IgG antibodies against the measles, mumps, and rubella (MMR) viruses in sera collected from first grade students in AS in April–May 2011. Vaccination status was retrieved from the immunization cards. Factors associated with seropositivity of measles, mumps, and rubella were analyzed separately. ResultAmong 509 first grade students, measles, mumps, and rubella seroprevalence were 92%, 90%, and 93%, respectively. The proportions of first grade students with documented one or two doses of MMR vaccine were 93% and 84%, respectively. The vaccination status of 6% of the first graders was unknown and 1% was unvaccinated. Receiving two-doses of MMR vaccines was associated with high measles and mumps seropositivity (p<0.01). ConclusionThe high measles seroprevalence among children shows the progress by American Samoa towards measles elimination. Achieving and maintaining high two-dose MMR vaccine coverage in all age groups will aid in attaining the measles elimination status and prevent transmission of measles from potential imported measles cases from other countries.

Health literacy, health empowerment and health information search in the field of MMR vaccination: a cross-sectional study protocol

ObjectivesAlthough public health offices have a detailed record of the vaccination coverage among adolescents in Switzerland, little is known about the factors that determine the decisions of parents to get...

Interruption of measles transmission in Gipuzkoa (Basque Country), Spain.

Measles vaccine was introduced in Gipuzkoa (Basque country, Spain) in 1978 and was replaced by the measles, mumps, and rubella (MMR) vaccine for children aged 12-15 months in 1981. A second dose of the MMR vaccine was introduced in 1992. Both doses of the MMR vaccine were well accepted by the population and high coverage was achieved (95% and 91% for the first and second doses respectively for the period 1993-2002). Measles virus circulation was interrupted in the second half of the 1990s: no cases of indigenous measles were notified between 1998 and 2003, and only imported cases have been confirmed during this period. These data indicate that the measles vaccination programme implemented has been effective. Nevertheless, to avoid measles outbreaks following viral introduction, high MMR vaccine coverage levels for the two doses have to be maintained (&gt;95%).

Association of autistic spectrum disorder and the measles, mumps, and rubella vaccine – A systematic review of current epidemiological evidence

The authors conducted a systematic review of the evidence for and against the existence of an association between autistic spectrum disorder and the measles, mumps and rubella (MMR) vaccine. Specifically, they tested four hypotheses: (1) that the rates of autistic spectrum disorder is higher in individuals who have received MMR than those who did not, (2) that an increase in autistic spectrum disorder may be occurring as a result of MMR, (3) that the development of autistic spectrum disorder is temporally associated with receiving the MMR, and (4) that a new variant form of autistic spectrum disorder may be associated with the MMR vaccine. The authors sought to identify all controlled epidemiological articles examining for an association between autistic spectrum disorder and the MMR vaccine. They extracted data from the articles on the characteristics and objectives of the study as well as evidence of an association.Twelve articles met the inclusion criteria. One study found no difference in the rates of autistic spectrum disorder and the MMR vaccine in children who were vaccinated and those who were not. Six studies examined for evidence of an increase in autistic spectrum disorder associated with an increase in the MMR vaccine coverage; none of the six showed evidence of an association. Four studies examined if a variant form of autistic spectrum disorder was associated with the MMR vaccine; none of the four showed evidence of an association. Eight studies attempted to determine if there was a temporal association between developing autistic spectrum disorder and receiving the MMR vaccine. Of these, one 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 autistic spectrum disorder and the MMR vaccine. The authors concluded that the current literature does not suggest an association between autistic spectrum disorder and the MMR vaccine. The authors did note that the studies were not large enough even in aggregate to rule out a link between a rare variant form of autistic spectrum disorder and the MMR vaccine; they held, however, that given the real risks of not vaccinating and that the risks and existence of variant autistic spectrum disorder remain theoretical, current policies should continue to advocate the use of the MMR vaccine.

Association of Autistic Spectrum Disorder and the Measles, Mumps, and Rubella Vaccine

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. 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. 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. 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.