The Northern Regional Health Authority (NRHA), along with virtually every health authority of competent jurisdiction in Canada, recently began making their annual pitches urging people to get a seasonal flu shot in the days and weeks ahead.
In Thompson, they arrived in residential mailboxes in the form of direct-mail annual flyers, starting out in bold type: "Seasonal Influenza 2013: The seasonal trivalent vaccine for this year provides active immunization against three influenza strains. It is important for everyone to get the flu shot every year." This year's seasonal trivalent vaccine is intended to provide active immunization against A/California/7/2009 (H1N1)-like virus, an H3N2 virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011 and a B/Massachusetts/2/2012-like virus.
Well, OK. There is after all nothing subtle, nuanced or qualified about many public health flu shot campaigns.
The Centers for Disease Control and Prevention in Atlanta, however, is fairly balanced and straight forward in its approach when it comes to discussing the efficacy of flu vaccines: "Recent studies show vaccine can reduce the risk of flu illness by about 60 per cent among the overall population during seasons when most circulating flu viruses are like the viruses the flu vaccine is designed to protect against." In other words, a reduced flu risk overall for six out of 10 people in a good year.
Dr. Steven Bratman, medical director for Employee Health at California Pacific Medical Center in SanFrancisco, noted Oct. 8: "The flu vaccine is least effective among one group that needs it more than most: seniors. Last year's flu vaccine was only about nine percent effective for people over 65."
In truth, how effective the flu shot is remains an unsettled question, annual flu shot campaigns notwithstanding. Flu shots can take two weeks to take full effect and the frequently cited estimate of 70 per cent to 90 per cent for influenza vaccine efficacy to prevent virologically-confirmed influenza in healthy adults was originally documented in studies conducted mostly in U.S. military personnel between 1943 and 1969, notes The Compelling Need for Game-Changing Influenza Vaccine: An Analysis of the Influenza Vaccine Enterprise and Recommendations for the Future, a 160-page study released last October by the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota.
Numbers like those offered by Bratman, the Centers for Disease Control and Prevention and Center for Infectious Disease Research and Policy at the University of Minnesota perhaps go some way to explaining why the rate for Canadian adults under the age of 65 getting an annual flu shot, annual public flu shot campaigns notwithstanding, is just 35 per cent. Among healthcare workers, it is 40 to 50 per cent.
Influenza season is an annual occurrence worldwide that generates coverage almost entirely proportionate to its severity in a particular geographic area in any given year. While it is always with us to some degree, it is the classic example of a contagious respiratory illness that when out of sight is out of mind.
We don't usually give it much thought in a mild flu season. But in a normal year anywhere from 50 to 100 Manitoba residents will die of influenza-related illness, the province says.
Until words like epidemic, or occasionally pandemic, enter our lexicon again in a bad flu season when antigenic drift can cause a relatively mild influenza strain one year to mutate into something more serious or contagious the next year, public health campaigns encouraging people to get an annual flu shot will often fall on deaf ears.
But even if the influenza vaccine only prevents infection 60 per cent to 70 per cent of the time, in the best of cases - meaning that of every 10 people who would have gotten the flu without the shot, three or four still will - flu shots have proven to be effective in slowing the virus down and helping to limit the spread of pandemics. On the balance of probabilities, you hopefully are helping yourself in getting a flu shot, but you're almost certainly in any event being altruistic in helping the rest of us in the general population by slowing the spread the virus down.
While there is no such thing as a sure thing when it comes to flu shots (or most of life, for that matter), the odds, while not perhaps quite as much in your favour as often hyped, still suggest you might want to seriously consider getting a flu shot.
While Dr. Bratman cautions against hyping how effective flu shots are, he also correctly notes, "Influenza is far worse than a cold - it's a powerful disease, once called grippe because it can feel like a giant squeezing one's life out ... Why not get a flu shot this fall? There is little or no downside, and considerable benefit for oneself andothers." A Globe and Mail editorial last Jan. 20, headlined, "Do your duty: get the flu shot" put it even more bluntly: "There is really no good argument against the jab: a responsible citizen should get the flu vaccine."
Besides, a wager against feeling like you were hit by a truck is a pretty reasonable bet in our books.
