Poll: 21.4% of Americans believe vaccines can cause autism

Thomson Reuters and NPR conduct the monthly poll to gauge attitudes and opinions on a wide range of health issues.

In the latest survey in the series, 26.6 percent of respondents expressed concern over the safety of vaccines. Households with children under the age of 18 demonstrated the greatest level of concern (30.8%).  The lowest level of concern (18.5%) was found in respondents 65 years old and up.

Among those with concerns, 47.3 percent attributed their fear of vaccines to future long-term impact on health and 46.0 percent said they were worried about side effects.

Nearly one in five said they have questioned or refused a vaccine for themselves or their children -- with a higher rate among those under 35 (28.1 percent) and a lower rate among those 65 and older (12.7 percent).

When asked about specific safety concerns, 21.4 percent of respondents said they believe vaccines can cause of autism, 9.2 percent said they believe vaccines can be linked to cancer, 6.9 percent believe they play a role in diabetes, and 5.9 percent cite a connection between vaccines and heart disease.

Overall, 24 percent of respondents said their opinions of vaccines have changed in the past five years. Of those, 59 percent say their views on vaccines have become less favorable.

"Ironically, these survey results are a testament to the effectiveness of vaccines: older people remember what illnesses like polio did to cripple and kill patients, but the younger generation has never seen someone with polio," said Raymond Fabius, M.D., chief medical officer at the healthcare business of Thomson Reuters. "Because of the elimination of diseases through immunization, there is a lack of understanding that the benefit of vaccines greatly outweighs the minimal risks of side effects both short and long term."