If the trajectory of public opinion during the H1N1 influenza pandemic is any guide, safety worries and doubts about the severity of the disease threat may cause a good share of the public to shun vaccination the next time a pandemic emerges, according to a review of 10 months' worth of polls.
Surveys taken before the H1N1 vaccine became available showed that about half of the population planned to be vaccinated, but that fraction shrank considerably by the time the vaccine became readily available in December, says the report published online today by the New England Journal of Medicine. The main reasons for not wanting the vaccine were safety worries and a belief that it wasn't needed.
On the other hand, the polls suggested that most people heeded public health messages about other flu-prevention steps, such as hand washing, says the report by researchers from Harvard University and the Centers for Disease Control and Prevention (CDC). Also, pollsters found that a majority had a generally favorable impression of the governmental response to the pandemic.
The authors reviewed 20 polls conducted between April 2009 and January 2010, eight of them run by the Harvard School of Public Health for the CDC and the rest by news organizations and polling institutes.
Early in the pandemic, surveys indicated that most Americans were following the public health advice to wash their hands more often and to prepare to stay home if they got sick. About 35% of respondents said they had avoided being near people with flu-like symptoms.
Before the vaccine became available, 46% to 57% of respondents said they planned to be vaccinated, and 59% to 70% of parents intended to have their children immunized.
For adults who said they would not or might not seek vaccination, the top three reasons cited in September were concern about side effects (30%), doubt about the risk of getting a serious case of flu (28%), and a belief that they could get drug treatment if they did get sick (26%). Safety concerns and doubts about the disease risk continued to be major deterrents to vaccination in December and January, the polls showed.
The surveys also documented that few people who wanted the vaccine succeeded in getting it in October and November, when the doses began trickling out to providers. By early November, 17% of adults had tried to get vaccinated, but only 30% of them succeeded. Among adults in high-priority groups, 21% sought the vaccine, but 66% of them failed, the polls found. About 40% of parents sought the vaccine for their children, but two thirds of them failed.
By the time states began offering the vaccine to everyone in mid-December, interest in it was ebbing, the polls showed. The proportion of people concerned about getting sick dropped to 40% at that point, from a peak of 51% to 59% in October and November.
The share of parents who had at least one child vaccinated reached 35% in December and 40% in January, figures well above those for adults seeking the vaccine for themselves. Among adults who had talked with a health care practitioner about the vaccine, 53% said the practitioner had recommended it and 17% said the opposite.
Through the whole period studied, a majority of Americans had a good impression of the government's response, the polls showed. In the early days, 54% thought the response was appropriate, while 39% saw it as an overreaction. By January, 59% endorsed the response, while 39% called it fair or poor.
The report says the public's two main concerns about the response were displeasure with the vaccine shortage and, in the early phase of vaccine distribution, worry that the government hadn't done enough to ensure the vaccine was safe.
