The Public's Response to the 2009 H1N1 Influenza Pandemic

Gillian K. SteelFisher, Ph.D., Robert J. Blendon, Sc.D., Mark M. Bekheit, J.D., and Keri Lubell, Ph.D
19 May 2010

In April 2009, a novel influenza A (H1N1) virus emerged in the United States with the key characteristics of a pandemic virus, and within weeks it had spread to every region in the country.1 Ultimately, the rate of death was lower than was initially predicted, but the numbers of H1N1 cases, hospitalizations, and deaths were nonetheless substantial,2 and the experience offers some lessons that may help us.

Given the crucial role that the public plays in containing or spreading illness and in seeking related medical care, we have examined the public's response to the 2009 H1N1 pandemic and relevant public health recommendations through a comprehensive review of available data from national public opinion polls conducted by telephone between April 2009 and January 2010 (see Polls on Public Response to H1N1). Our sources include 20 polls, 8 of which were conducted by the Harvard School of Public Health (HSPH) through cooperative agreements with the Centers for Disease Control and Prevention (CDC), the National Preparedness Leadership Initiative, and the National Public Health Information Coalition. We examined the extent to which people adopted specific behaviors during three periods: the early months of the pandemic, when no vaccine was available; at the time of the initial, delayed release of vaccine to high-priority groups; and after the vaccine was widely available. We also examined the reasons why many Americans did not get vaccinated and reviewed the public's view of the government's response to the pandemic. In instances in which multiple polling questions were relevant, we present a range of findings.

Early in the pandemic, when no vaccine was available, a majority of Americans were quick to adopt two central public health recommendations. In the pandemic's first weeks, almost two thirds of Americans (59 to 67%) said that they or someone in their family had begun to wash their hands or clean them with sanitizer more frequently, and a majority (55%) had made preparations to stay at home if they or a family member got sick. It was also recommended that people avoid exposure to others with influenza-like symptoms, and 35 to 38% said they had done that (HSPH, April, May, and June 2009).

Measures for reducing interactions with other people were not recommended as routine practice. Nonetheless, polls suggest that 16 to 25% of Americans had avoided "places where many people are gathered, like sporting events, malls, or public transportation," and 20% had "reduced contact with people outside [their] household as much as possible." Fewer had adopted related measures. For example, 4 to 8% said they or family members had worn a face mask, and 1 to 3% got a prescription for or purchased antiviral drugs (HSPH, April, May, and June 2009).

Between July, when discussions about vaccine availability increased, and October, when a limited amount of vaccine became available, the public was divided over whether they would get vaccinated. Roughly half (46 to 57%) of the public said they expected to receive the vaccine (AP, July, September, and October 2009; Fox, September 2009; HSPH, August−September and September 2009; CBS, October 2009); a higher percentage of parents −59 to 70% − said they expected to get their children vaccinated (CBS, August and October 2009; HSPH, September 2009).

In making their decision, some people appeared to think there was a trade-off between accepting the perceived risk associated with the illness and accepting any perceived risk associated with the vaccine. Sixty percent of adults who initially said they did not intend to get the vaccine for themselves and parents who initially said they did not intend to get the vaccine for their children also said that they would change their mind if "there were people in [their] community who were sick or dying from influenza A (H1N1)" (HSPH, September 2009).

There were two major reasons why people said they would not or might not get the H1N1 vaccine, one of which was concern about its safety. Among adults overall, this concern was present but not dominant: most (87%) believed the H1N1 influenza vaccine was "very safe" or "somewhat safe." However, only 33% believed it was "very safe," as compared with 57% who said the same of the seasonal influenza vaccine (HSPH, September 2009). Among adults who said they would not or might not get the H1N1 vaccine, concerns about getting H1N1 influenza, another serious illness, or other side effects from it were top "major reasons" for their decision (cited by 21%, 20%, and 30%, respectively). Parents who said they would not or might not have their children vaccinated were even more concerned about safety: 33% cited concern about exposure to another serious illness from the vaccine. Furthermore, a higher percentage of these parents than of adults overall indicated that they did not trust public health officials to provide correct information about the vaccine's safety (31% vs. 19%; HSPH, September 2009).

The other major reason for avoiding the H1N1 vaccine was the belief that it was not needed. Among adults overall, 47 to 50% said they were not concerned that they or their family members would get sick with H1N1 in the next 12 months (HSPH, August−September and September 2009). Among adults who said they would not or might not get the vaccine, the second and third most commonly reported reasons were a belief that they were not at risk for getting a serious case of H1N1 infection (28%) and the idea that if they did acquire H1N1, they could get medication to treat it (26%). A similar fraction (27%) of parents who said they would not or might not have their child vaccinated said that they did not think their child was at risk for getting a serious case (HSPH, September 2009).

During October, a limited amount of H1N1 influenza vaccine became available and was generally earmarked for high-priority groups, as defined by the CDC's Advisory Committee on Immunization Practices.3 By early November, 17% of adults had tried to get the vaccine for themselves, but 7 in 10 (70%) were unable to get it, so only 5 to 6% had been vaccinated (HSPH, October−November 2009; Gallup and AP, November 2009). Among high−priority adults, one in five (21%) tried to get the vaccine, but two thirds (66%) of them were unable to get it. Thus, only 7% of high-priority adults were actually vaccinated (HSPH, October−November 2009). Children, who were also prioritized, had higher vaccination rates than adults. Roughly 4 in 10 parents (41%) tried to get the vaccine for their children, and two thirds (66%) were unable to do so, meaning that 14 to 17% of parents had their children vaccinated (HSPH, October−November 2009; Gallup and AP, November 2009). Among people who tried and failed to get the vaccine, more than half (55%) said they were frustrated, but 91% said they would try again (HSPH, October−November 2009).

The vaccine was released more widely in mid-December, at the same time that concern about getting sick with H1N1 declined: the proportion of people who were concerned about getting sick had dropped from the peak of between 51 and 59% in October and November (AP, October 2009; Marist, October 2009; AP, November 2009) to 40% by mid-December (HSPH, December 2009). At that time, 14% of adults had received the vaccine. Seventeen percent and 21% had received it by early and mid-January, respectively, in a poll in which adults were defined as 19 years of age or older4 (HSPH, January 2010). In mid−January, an additional 16% said they intended to get it "by the end of February 2010." Substantially fewer adults had received the vaccine by mid−January than had expressed interest in receiving it when asked during the period from July through October.

A substantially greater proportion of parents had gotten the vaccine for their children than did adults for themselves: 35% of parents had had one or more of their children vaccinated by mid−December, and 40% had done so by mid−January. In addition, 13% of parents said they intended to have children vaccinated "by the end of February 2010" (HSPH, December 2009 and January 2010). In total, 29% of those 6 months to 19 years of age had received the vaccine.

During the December−January period, a belief that the vaccine was not safe or that it was not needed continued to be a major factor in the decisions of adults who said they were not going to or might not get the vaccine. Parents who said they were not going to or might not get the vaccine for their children were even more likely than the parallel group of adults to cite safety concerns as a reason (56% vs. 35%; HSPH, January 2010).

By December, a quarter (24%) of adults had talked to a doctor or other health care professional about getting the H1N1 vaccine for themselves, and of those, 53% said the practitioner had recommended getting the vaccine, 17% said that the practitioner had recommended against it, and 30% said that the practitioner had made no recommendation either way. More than a third (37%) of parents talked to a doctor or other health care professional about getting the H1N1 vaccine for their child, and of those, two thirds (64%) said that the practitioner had recommended getting the vaccine, 10% said that the practitioner had recommended against it, and 25% said that the practitioner had made no recommendation (HSPH, December 2009).

Throughout the H1N1 pandemic, more than half the U.S. population appeared to have a positive impression of the government's response, although a sizable minority did not. For example, in the early days of the pandemic, 54% believed the response of the federal government was appropriate, whereas 39% believed the government had overreacted (CNN, May 2009). Nine months later, in January 2010, 59% believed that public health officials did an excellent or good job in their overall response to the pandemic, whereas 39% believed they did a fair or poor job (HSPH, January 2010).

The public expressed two particular concerns about the government's response. First, some people were displeased with the vaccine shortage, and while the shortage existed, a majority of respondents (54%) said the federal government was doing a poor or very poor job of providing the country with adequate vaccine supplies (Gallup). Second, the public was divided about public health officials' efforts to make sure the H1N1 vaccine was safe early in the distribution process, even though two thirds (63%) of the public said in January that "public health officials had done the right amount to make sure the H1N1 flu vaccine is safe" (HSPH, January 2009). For example, in November, adults were nearly evenly divided on whether medical testing of the H1N1 influenza vaccine had moved too quickly to ensure that it was safe: 45% said it was done as quickly as possible while still making sure the vaccine was safe, whereas 40% said it was done too quickly so that people could not be sure it was safe (Fox, November 2009).

Our review of these data suggests that in the event of a future influenza pandemic, a substantial proportion of the public may not take a newly developed vaccine because they may believe that the illness does not pose a serious health threat, because they (especially parents) may be concerned about the safety of the available vaccine, or both. More work may need to be done to understand the basis of these beliefs and to address them in the case of a serious influenza outbreak.

Polls during the 2009 H1N1 pandemic also suggest that public health communication efforts related to other personal influenza-prevention behaviors were effective in reaching a large swath of the public. Building on these efforts, as well as developing a vaccine strategy, may be useful during response planning and during an outbreak.

Polls on Public Response to H1N1

Associated Press−GfK Roper (AP) polls (July 16−20, 2009; September 3−8, 2009; October 1−5, 2009; November 5−9, 2009) CBS News polls (August 27−31, 2009; October 5−8, 2009) CNN−Opinion Research poll (May 14−17, 2009) Fox News−Opinion Dynamics polls (September 15−16, 2009; November 17−18, 2009) Gallup−USA Today poll (November 6−8, 2009) Harvard School of Public Health (HSPH) polls (April 29, 2009; May 5−6, 2009; June 22−28, 2009; August 28−September 9, 2009; September 14−20, 2009; October 30−November 1, 2009; December 16−17, 2009; January 20−24, 2010) Marist College Institute for Public Opinion poll (October 7−12, 2009)

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Disclosure forms provided by the authors are available with the full text of this article at NEJM.org.

Source Information

From the Harvard School of Public Health, Boston (G.K.S., R.J.B., M.M.B.); the John F. Kennedy School of Government, Harvard University, Cambridge, MA (R.J.B.); and the Centers for Disease Control and Prevention, Atlanta (K.L.).

This article (10.1056/NEJMp1005102) was published on May 19, 2010, at NEJM.org.

References

1.H1N1: meeting the challenge. Washington, DC: Department of Health and Human Services. (Accessed May 17, 2010.)

2.CDC estimates of 2009 H1N1 cases, hospitalizations and deaths in the United States, April 2009−March 13, 2010. Atlanta: Centers for Disease Control and Prevention, April 2010. (Accessed May 17, 2010, at.)

3.Idem. 2009 H1N1 vaccination recommendations. Atlanta: Centers for Disease Control and Prevention, October 15, 2009. (Accessed May 13, 2010.)

4. Interim results: influenza A (H1N1) 2009 monovalent vaccination coverage — United States, October−December 2009. MMWR Morb Mortal Wkly Rep 2010;59:44−8. (Also available at .)

Source:

http://www.flu.gov/timeline

http://www.cdc.gov/h1n1flu/estimates_2009_h1n1.htm#Table%20Cumulative

http://www.cdc.gov/h1n1flu/vaccination/acip.htm

http://www.cdc.gov/mmwr/pdf/wk/mm59e0115.pdf