With reports of the H1N1 (and now H5N1) flu virus on the rise, William Bowie, a professor in UBC’s Faculty of Medicine who specializes in infectious diseases, says don’t panic, but take all necessary precautions.
The mention of H1N1 strikes fear into people, partly due to its dramatic entry as ‘swine flu’ in 2009. Should we pay special attention to this strain?
We should pay attention to all strains of influenza that affect humans because all can result in severe disease or death. Typically strains other than H1N1 disproportionally affect very young children, the elderly, and those with an immune system that is compromised by underlying diseases or medications. Death rates are particularly high in the elderly. H1N1 is unusual because many of the infections occur in children and younger adults, and illness can rapidly become severe and even fatal.
The overall impact of H1N1 is not markedly different from other strains of influenza, but its impact is more visible. Even now, when it is obvious that some children and young adults are getting severe disease from H1N1, it has not actually been an unusual year in terms of influenza impact.
Health experts agree that vaccination is our best defence against the flu, but there’s still much resistance – why do you think that is?
For reasons that do not stand up to objective scrutiny, there continue to be vocal lobbies and individuals who not only reject the use of vaccines, but occasionally spread myths or outright lies against their use. For these folks, the likely drivers are a general rejection of use of vaccines, or paranoid beliefs about ‘big pharma’ and government, or fear of reactions to vaccines. Others have mistaken beliefs about vaccine failures – a typical story being that I or someone I know had the vaccine and still got a flu-like illness. This is rarely actually shown to be influenza but rather one of the myriad other illnesses that can cause flu-like symptoms. Other people mistakenly believe that influenza is trivial, or that they are somehow protected from getting it.
That is not to say, however, that the influenza vaccines we now have are without drawbacks. They do not provide absolute protection against influenza. But depending on the vaccine components, the specific strains of influenza that circulate that year, prior exposure to vaccines or influenza and underlying disease and age, getting vaccinated against influenza does provide some protection. Even when protection is not absolute and one develops symptoms from influenza, the disease doesn’t make you as sick. The risks from influenza vaccines are generally trivial and for vulnerable populations, the benefits substantially exceed the risks.
For those who want to get the vaccine, is there an optimal time and is it ever too late?
The optimal time to be vaccinated is before the influenza season starts, which in B.C. is usually November or December. However during the flu season, which lasts into the spring, three or occasionally more strains of influenza will circulate, often sequentially. So even if the influenza season has started, it is not too late to get vaccinated because there will be some protection against strains that you haven’t yet been exposed to.