Summary: A new survey found that 24% of American adults incorrectly believe the MMR vaccine causes autism, despite evidence to the contrary from the CDC.
This misconception contributes to vaccine hesitancy and increased measles cases. The survey highlights the need for better public education about vaccine safety.
Highlights:
- 24% of American adults incorrectly believe that the MMR vaccine causes autism.
- Measles cases in the United States have increased significantly, with 146 cases in 2024.
- The CDC does not confirm any link between the MMR vaccine and autism.
Source: University of Pennsylvania
As measles cases rise in the United States and vaccination rates for the MMR (measles, mumps, rubella) vaccine continue to decline, a new survey finds that a quarter of American adults are unaware that the claims that the MMR vaccine causes autism are false.
The Centers for Disease Control and Prevention (CDC) has stated that there is no evidence linking the measles vaccine to autism. But 24 percent of U.S. adults don’t accept that — they think the statement is somewhat or very inaccurate — and 3 percent aren’t sure, according to a survey by the Annenberg Public Policy Center (APPC) University of Pennsylvania.
About three-quarters of those surveyed believe this statement to be somewhat or very accurate.
The results are consistent with those of an APPC survey administered by NORC in October 2018, before the Covid-19 pandemic. Both surveys indicate that a large and consistent number of Americans either believe the false link or don’t know what is correct. The false link was claimed by Andrew Wakefield in a 1998 Lancet article that was later retracted.
“The persistent false belief that the MMR vaccine causes autism continues to be problematic, especially in light of the recent increase in measles cases,” said Kathleen Hall Jamieson, director of the Annenberg Public Policy Center.
“Our vaccination studies consistently show that the belief that the MMR vaccine causes autism is associated not only with reluctance to take the measles vaccine, but with vaccine hesitancy in general.”
The new survey results are also consistent with APPC surveys from 2021 to 2023, which did not mention CDC guidelines.
In these surveys, 9 to 12 percent thought it was probably or definitely true that vaccines given to children for diseases like measles, mumps and rubella cause autism, while 17 to 18 percent did not know 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 selected U.S. adults about their knowledge of how one can get measles, its symptoms and whether health care professionals recommend that pregnant people get vaccinated against measles. if they haven’t already done so.
The growth of measles cases
The CDC reports that measles activity is increasing globally as well as in the United States.
In 2024, as of May 30, there have been 146 cases of measles in the United States across 21 jurisdictions, including 11 outbreaks of three or more related cases. From January 1, 2020 to March 28, 2024, the CDC was notified of 338 confirmed cases, nearly a third of which (97, or 29%) occurred during the first quarter of 2024 alone, representing a 17-fold increase compared to 2024. the average number of cases reported during the first quarters of 2020-2023.
The median age of patients was 3 years. The vast majority of cases occurred in patients who were unvaccinated or whose vaccination status was unknown.
The percentage of kindergartners with MMR measles vaccination coverage has fallen in the United States during the pandemic, according to the CDC. “Measles outbreaks increase amid falling vaccination rates,” headlines a November 2023 JAMA Network headline.
Knowledge of measles
How measles spreads
The majority of people surveyed know how measles can and cannot spread. Nearly 6 in 10 people correctly say that measles can be spread by coughing and sneezing (59%) and by contact with a contaminated surface followed by contact with the nose, mouth or eyes (59% ).
Measles cannot be transmitted through unprotected sexual contact with an infected person, but more than a fifth of people surveyed (22%) believe this is a way to contract the virus.
Measles incubation period
Very few people surveyed know how long a person infected with measles can spread the virus before developing the characteristic measles rash. Just over 1 in 10 (12%) correctly estimate that a person can spread the infection for four days before developing a rash, while 12% estimate that period is a week. The majority of panelists (55%) say they are not sure.
Complications of measles for pregnant women
The survey asked respondents to indicate whether a range of possible complications were associated with measles during pregnancy. Fewer than 4 in 10 people (blue below) correctly identified two complications associated with measles during pregnancy: delivering a low birth weight baby (38%) and early delivery (37 %).
Quite a small number of people (in yellow below) incorrectly say that diabetes (7%), blurred vision (11%) and death (12%) are more likely to occur if you have measles during pregnancy. pregnancy. They are not.
Measles vaccination (MMR) during pregnancy
Most people (57%) are unsure whether pregnant women should get the measles vaccine if they haven’t already. Nearly a third (32%) incorrectly believe that healthcare professionals recommend that pregnant people get vaccinated.
Only 12% know that health professionals do not recommend this vaccine for pregnant women. This is because the measles vaccine uses a live, weakened (i.e. attenuated) form of the virus.
The CDC notes: “Even though the MMR vaccine is a safe and effective vaccine, there is a theoretical risk to the baby. This is because it is a live vaccine, which means that it contains a weakened version of live viruses. »
The CDC recommends that the MMR vaccine be given a month or more before a person becomes pregnant, if that person was not vaccinated against measles, mumps, and rubella as a child.
APPC ASAPH survey
The survey data comes from 19th wave of a nationally representative panel of 1,522 U.S. adults, first assembled in April 2021, conducted for the Annenberg Public Policy Center by SSRS, an independent market research firm.
This wave of the Annenberg Science and Public Health Knowledge (ASAPH) survey was conducted April 18-24, 2024 and has a margin of sampling error (MOE) of ±3.5 percentage points at the confidence level of 95%.
All figures are rounded to the nearest whole number and may not add up to 100%. Combined subcategories may not add up to top row and text totals due to rounding.
The Policy Center has been tracking the American public’s knowledge, beliefs, and behaviors regarding vaccination, Covid-19, influenza, maternal health, climate change, and other consequential health issues through this survey panel since more than three years.
In addition to Jamieson, the APPC team behind this investigation includes Shawn Patterson, who analyzed the data; Patrick E. Jamieson, director of the Annenberg Health and Risk Communication Institute, who developed the questions; and Ken Winneg, Managing Director of Survey Research, who oversaw the completion of the survey.
The 2018 survey data comes from the first wave of the Annenberg Public Policy Center’s Vaccine Resistance Longitudinal Survey (RVLS), a panel of 3,005 U.S. adults, conducted by NORC, an independent research firm.
This wave 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 the latest research on denial of vaccination
Author: Michael Rozanski
Source: University of Pennsylvania
Contact: Michael Rozansky – University of Pennsylvania
Picture: Image is credited to Neuroscience News