What you should know about H1N1


by Alan Cassels

This season’s flu bug known as Swine flu or H1N1, seems to have prompted a lot of people to ask me, “Should I get vaccinated or not?” I have been quite loathe to write anything on the Swine flu for the simple reason that Canada’s media is already doing a superb job of filling daily newspaper pages and the airwaves and TV channels. They’re covering every tick and wrinkle in the vaccine development plan: the world’s pandemic preparedness, timing and access to the vaccines and so on, ad nauseam. However, my publisher insisted, so let me apologize in advance for adding my two cents to the din.

Is this pandemic worth worrying about?

Probably not. If we can learn from the experience from the southern hemisphere, which just had its flu season, mortality from the pandemic appeared to be relatively low and most countries had flu-related mortality rates of less than one person per 100,000. That’s tiny.

Does the vaccine work? 
It depends on your definition of ‘work.’ It ‘works’ in terms of helping you develop antibodies if you get the shot. However, are those antibodies enough to keep you from getting sick? We all know people who got the flu shot and still got the flu, right? When people tell you the flu vaccine reduces mortality by 50 percent, you need to know that these stats come from “cohort studies,” which compare death rates in vaccinated people versus non-vaccinated people. The truth is, those two groups may be very fundamentally different to start with and the vaccine might have had nothing to do with the observed outcomes. This “Healthy User Bias” is a usual feature of low-quality drug trials. Only random assignment or randomization can really prevent this.

But what about the Spanish flu of 1919? 
Couldn’t the Swine flu pandemic be a repeat of this massively deadly pandemic? Not likely. It’s healthier to think in terms of probabilities, not possibilities. While it is possible an asteroid could strike the earth tomorrow and kill us all, this is improbable. The Spanish flu had a high death count partly because it took place in a poorer, less hygienic and antibiotic-free world than what we have today.

But surely the H1N1 flu is severe and deadly? 
Compared to what? The regular run of the mill seasonal flu? Nope. There is substantial evidence that the mortality rate from H1N1 flu is actually much smaller than from the seasonal flu.

Young people are getting it and some are dying. Surely, the public health people can’t be wrong. 
Not entirely. If they didn’t push a mass immunization campaign, they wouldn’t be doing their jobs. Focusing on death in the outliers isn’t productive and repeating the refrain that the vaccine is “safe and effective” sounds strained. Do we need reminding that in 2005 the World Health Organization (WHO) predicted that up to 150 million people could die from Avian flu? (The eventual death toll was 262 people.)

Isn’t it public spirited to get vaccinated so you won’t spread the virus to others? 
Sounds plausible, but is that recommendation evidence-based? Have researchers, who have combed through hundreds of flu-vaccine studies, found studies suggesting this kind of effect for the general population? No. Of hundreds of studies on flu immunization, only about four are of sufficient rigour to say anything definitive and two of those studies showed the vaccine to be useless.

Is the vaccine ‘safe’? Adjuvanted vaccine or non-adjuvanted? 
Again, depends on what you mean by ‘safe’. Within the bounds in which it was studied, the H1N1 vaccine doesn’t appear to have much of a tendency to produce adverse effects. I don’t think anyone can say with certainty that the adjuvanted vaccines are more dangerous than the other. And no one on the planet has any answers about the long-term safety of the current flu vaccines. No one.

What’s your bottom line? What needs to be done to eliminate all the uncertainty about the vaccine? 
More research. Better research like large, placebo-controlled RCTs (randomized controlled trials) on the annual flu shot will erase some of these controversies and establish where the benefits are. If we followed patients over the long term, we could get a much clearer picture of the vaccine’s safety and effectiveness and the effects of natural immunity. Some say that studying the sacred flu shot with randomized, placebo-controlled trials is unethical. To me, it is unethical to carry on large- scale, hype-inducing public health policies without collecting the data (through randomized trials) needed to prove we are buying the health outcomes we think we are. I am not getting the vaccine, but I would if they agreed to include me as a study subject: “If they randomize, I’ll immunize.”

Any last words? 
My final recommendation: lighten up folks; it’s only the flu. Let’s see a government policy of calmness coupled with accurate information for both professionals and public. Hype can make us all ill.

Leave a comment