Asthma and flu shots.
A new study finds that over a third of Canadians with asthma have never been vaccinated against the flu and that many of them believe that they’re “too healthy” to be in need of the flu shot. The findings are a concern, say the study’s authors, who point to the higher risk among asthmatics of severe complications from the flu.
With the flu season now having passed its peak, Canadian health officials are reporting that this year’s flu was somewhat harsher than last year’s, thanks to the H3N2 strain which predominated, a form of the virus that is particularly hard on the elderly, can produce more severe symptoms and is less responsive to the flu vaccine.
Yet this year’s flu shot has been declared a moderate success, nonetheless, having produced a 42 per cent effectiveness rating, according to estimates — enough to effectively cut in half the risk of getting sick enough to require medical attention for those who received the flu shot.
And while for some, getting the flu mostly means time missed from work, for others the illness can be more serious. Every year in Canada, about 12,000 hospitalizations are caused by influenza and 3,500 deaths, with the very young and the elderly among those most prone to severe illness.
Those with chronic respiratory conditions like asthma are also at higher risk, as studies show that asthma is the most common chronic condition in patients hospitalized with influenza. Thus, for the 2.2 million Canadians adults living with asthma, annual flu shots are highly recommended.
But only a minority of Canadians with asthma actually receive vaccination each year. A 2009 study found that somewhere between 36 and 48 per cent of Canadians with asthma or chronic obstructive pulmonary disease (COPD) get immunized against the flu, numbers that are comparable to those recorded in Europe and the United States.
Health researchers have delved into the reasons why people in the general population forgo getting vaccinated. Typically cited are claims that one is too busy (the “just didn’t get around to it” excuse), assumptions that the shot isn’t necessary for them in particular (“I’m healthy enough to go it alone”) and perceptions that the flu vaccine either produces negative side effects or that it doesn’t work anyway.
None of these should be persuasive in the case of people with asthma and COPD, say health experts, nor with the general population, but until the present study, exactly why immunization numbers for those with chronic asthma remain low had yet to be clearly identified.
The new study comes from researchers at the School of Population and Public Health at UBC and the Dalla Lana School of Public Health at the University of Toronto who looked at data from four cycles over the past dozen years of the Canadian Community Health Survey. Among other topics, the CCHS asks individuals about whether they have ever received a seasonal flu shot and if not, what their reasoning was. Researchers found that of the 29,608 respondents to the survey recorded as having asthma, 36.3 per cent reported never having had a flu shot and that within that group, 74.8 per cent chose “not necessary” as the reason for not getting the shot while 11.7 per cent chose “not gotten around to it” as their reasoning.
The study’s authors say the poor numbers point to the belief among those with asthma who have never gotten the shot that they are “healthy enough,” something described as a typical coping mechanism for those dealing with chronic illness. “Many individuals with chronic conditions attempt to ‘normalize’ their condition, developing ways to manage and adapt to symptoms,” say the study’s authors, “which may explain the high proportion of adults with asthma who self-rated their health as good to excellent and who, in turn, perceive influenza vaccination as unnecessary.”
The researchers say their results speak to the need for more engagement of physicians and the health care system in promoting the benefits of the flu shot on an individual basis. “Given that primary healthcare providers have a great deal of influence in the vaccination decisions of their patients, encouraging physicians to personalize the risks of non-vaccination to their patients with asthma, to recommend vaccination, and to provide information on the effectiveness of influenza vaccination in asthmatic adults might be the best strategy,” say the study’s authors.
The study is published in the journal PLoS One.