summary: A new survey finds that 24% of U.S. adults mistakenly believe the MMR vaccine causes autism, despite CDC evidence to the contrary.
This misconception has led to vaccine hesitancy and increased measles cases, and this study highlights the need for improved public education about vaccine safety.
Key Facts:
- 24% of U.S. adults mistakenly believe that the MMR vaccine causes autism.
- Measles cases in the United States have increased significantly, reaching 146 cases in 2024.
- The CDC has confirmed there is no link between the MMR vaccine and autism.
sauce: University of Pennsylvania
As measles cases rise across the United States and MMR (measles, rubella, and mumps) vaccine uptake rates continue to decline, a new survey finds that a quarter of American adults are unaware that the claim that the MMR vaccine causes autism is false.
The Centers for Disease Control and Prevention (CDC) has said there is no evidence linking measles vaccination to the onset of autism, but a survey by the Annenberg Public Policy Center at the University of Pennsylvania found that 24% of American adults don’t accept this, calling the statement somewhat or very inaccurate, and an additional 3% are not sure.
Nearly three-quarters of those surveyed said this statement was somewhat or very accurate.
The results are consistent with those of an APPC survey conducted by NORC in October 2018, before the COVID-19 pandemic. The two surveys indicate that a significant number of Americans believe the false association or are unsure what is true. The false association was first asserted by Andrew Wakefield in a 1998 paper published in The Lancet that was subsequently retracted.
“The persistent, erroneous belief that the MMR vaccine causes autism remains troubling, especially in light of the recent increase in measles cases,” said Kathleen Hall Jamieson, director of the Annenberg Public Policy Center.
“Our research on vaccinations has consistently shown that the belief that the MMR vaccine causes autism is associated not only with reluctance to receive the measles vaccine, but also with hesitancy about vaccinations in general.”
The new findings are consistent with the 2021-2023 APPC survey, which did not mention the CDC guidance.
In these surveys, 9% to 12% of people thought it was probably or definitely true that vaccinating children against diseases such as measles, mumps and rubella causes autism, while 17% to 18% were not sure whether it was true or false.
In the latest survey, conducted April 18-24, 2024, the Annenberg Public Policy Center asked more than 1,500 U.S. adults about their knowledge of how measles is transmitted and its symptoms, as well as whether medical professionals would recommend the measles vaccination for pregnant women who have not already been vaccinated.
Increase in measles cases
The CDC reports that measles outbreaks are increasing in the United States and around the world.
As of May 30, 2024, there were 146 measles cases in 21 jurisdictions in the United States, including 11 cases with three or more associated cases. From January 1, 2020 through March 28, 2024, CDC was notified of 338 confirmed cases, of which approximately one-third (97, 29%) occurred in the first quarter of 2024, which is 17 times the average number of cases reported in the first quarter of 2020-2023.
The median age of the patients was 3 years. The majority of cases occurred in patients who were unvaccinated or whose vaccination status was unknown.
According to the CDC, during the pandemic, the percentage of preschoolers in the United States who received the MMR vaccine against measles has declined. A November 2023 JAMA Network headline noted, “Measles Incidence Rise Amid Falling Vaccination Rates.”
Measles Knowledge
How measles is transmitted
The vast majority of survey respondents know how measles can and cannot be spread: Nearly 6 in 10 correctly say that measles can be spread by coughing or sneezing (59%) or by touching a contaminated surface and then touching your nose, mouth or eyes (59%).
Measles cannot be transmitted through unprotected sex with an infected person, but more than a fifth (22%) of people surveyed believe this is how the virus is transmitted.
Measles incubation period
Few people surveyed knew how long someone with measles can spread the virus before the measles-specific rash appears: Just over one in ten (12%) correctly estimated that someone can spread the virus for four days before the rash appears, and 12% estimated that it’s one week. The vast majority of survey respondents (55%) said they weren’t sure.
Measles complications in pregnant women
The survey asked respondents to select a set of complications that could result from catching measles while pregnant. Fewer than four in ten correctly identified two complications that could result from catching measles while pregnant (shown in blue below): giving birth to a low birth weight baby (38%) and premature birth (37%).
A significant number of people mistakenly point out that catching measles during pregnancy increases the chances of developing diabetes (7%), vision loss (11%), and death (12%) (see yellow areas in the image below). This is not true.
Measles vaccination during pregnancy (MMR)
Most people (57%) are unsure whether pregnant women should get vaccinated against measles if they haven’t already, and about a third (32%) incorrectly believe health professionals recommend that pregnant women get the vaccine.
Only 12% know that medical professionals do not recommend this vaccine for pregnant women because the measles vaccine uses a weakened live virus.
The CDC points out: “MMR is a safe and effective vaccine, but it does carry theoretical risks for your baby because it is a live vaccine, meaning it contains a weakened version of the live virus.”
The CDC recommends that people who were not vaccinated against measles, mumps, and rubella as children receive the MMR vaccine at least one month before becoming pregnant.
APPC ASAPH Survey
The survey data is from 19Number The series of surveys of a nationally representative panel of 1,522 U.S. adults, first selected in April 2021, was conducted by independent market research firm SSRS for the Annenberg Public Policy Center.
The Annenberg Science and Public Health Knowledge (ASAPH) Poll was conducted April 18-24, 2024, and has a sampling margin of error (MOE) of ± 3.5 percentage points at the 95% confidence level.
All numbers have been rounded to the nearest whole number and may not add up to 100%. Combined subcategories may not equal topline and text totals due to rounding.
Through this survey panel, the Policy Center has tracked Americans’ knowledge, beliefs, and behaviors regarding vaccinations, COVID-19, influenza, maternal health, climate change, and other major health issues for more than three years.
In addition to Jamison, the APPC team behind the survey includes Shawn Patterson, who analyzed the data, Patrick E. Jamison, director of the Annenberg Institute for Health and Risk Communication, who developed the questions, and Ken Wineg, managing director of survey research, who oversaw the survey’s implementation.
The 2018 survey data came from the first wave of the Annenberg Public Policy Center’s Vaccine Resistance Longitudinal Study (RVLS), which surveyed 3,005 U.S. adults and was conducted by the independent research firm NORC.
The survey was conducted between September 21, 2018 and October 6, 2018, and has a margin of sampling error of ± 2.6 percentage points at the 95% confidence level.
About this conspiracy theory, ASD, and vaccine denial research news
author: Michael Rozanski
sauce: University of Pennsylvania
contact: Michael Rozanski – University of Pennsylvania
image: Image courtesy of Neuroscience News
