Universal flu shots: the $125-million question

[Guest guest]

Web-exclusive Comment

 

Universal flu shots: the $125-million question

http://www.theglobeandmail.com/servlet/story/RTGAM.20041129.wfluu29/BNStory/Fron\

t/

 

By ALAN CASSELS and JIM WRIGHT

Globe and Mail Update

POSTED AT 1:07 AM EST Monday, Nov 29, 2004

 

This flu season so far has been quirkier than most, with more twists and

turns than a B-grade slasher movie. We can tell you we are glued to our

seats watching Canada's media have a field day, expending barrels of ink

on the ups and downs of this season's flu saga.

 

First there was the U.S. vaccine supply-shortage story, dooming millions

of Americans to certain illness this winter. Then came the news claiming

that we can stretch the vaccination supply by just squirting a little of

it under the skin, followed by a Dutch study that says people who get

annual flu shots live longer. And just out is a story in the Canadian

Medical Association Journal on new research saying that doctors should

be recommending the flu shot for every Canadian.

 

On top of it, ironies abound as American citizens, whose government

likes to spurn Canadian-made drugs as " unsafe, " are arriving here in

Victoria by the boatload and lining up for the flu vaccine that they

can't get back home. There's nothing like making something a teensy bit

scarce to drive up its perceived value. In fact, the U.S. seniors

arriving at Victoria's docks are fuelling the hype and hysteria that is

causing thousands more of us to get the shot. Demand in Canada for the

flu vaccine is apparently 25-per-cent higher than last year.

 

Yet amid the flu frenzy, two very important questions aren't given much

airplay: What is an average person's risk of catching the flu? And what

is the ability of the flu shot to actually prevent it?

 

Those are two pretty vital questions worth examining, seeing as it would

cost us Canadian taxpayers up as much as $125-million a year to immunize

all 32 million of us for the flu.

 

Despite persistent and scary references to a deadly epidemic ready to

sweep the globe, the actual incidence of flu in healthy adults is

relatively low. In that recent CMAJ analysis, the authors analyzed more

than 18 flu-vaccine trials and reported that the rate of flu is

somewhere between 1.3 per cent and 20 per cent. This seems rather low,

considering the numbers of colds and other nasty respiratory illnesses

many of us get in the winter. But the flu shot does nothing to prevent

those other non-influenza viruses from getting us.

 

And if we get the flu shot, how well does it actually work?

 

The efficacy was reported as somewhere between 0 per cent and 18 per

cent, depending on which outcome is being measured - hospitalizations,

illnesses, or absent days from work. The kicker is that the efficacy of

the flu vaccine we get each year depends wholly on the ability of

scientists to predict the previous spring what they think will be the

dominant flu strains that year. It's a crap shoot, a guessing game. And

they often get it wrong, as they did last year.

 

Public-health officials in Canada seem to be saying everyone needs a flu

shot. We contend that it is possible that both the " disease " caused by

influenza viruses and the preventative vaccine regimes pushed on healthy

people are so hyped they border on disease-mongering. We think it's

likely not worth spending $125-million to vaccinate all of us each year

for this condition.

 

After all, how much reduction in absenteeism, hospitalizations or even

deaths will $125-million buy us?

 

No one really knows the answer. It would probably cost us less than

$100,000 to find out. It would be incredibly easy to set up a proper,

randomized, placebo-controlled, double-blind study of the flu vaccine,

tested on people from all groups - healthy people, the elderly and children.

 

We need a trial - because despite the breathless pronouncements over the

flu, there is genuine scientific controversy over immunizing people for

something that they probably won't get and for which the outcomes are

uncertain. Like any medical intervention, there are some short-term

adverse effects we can predict, and long-term ones we can't predict.

 

A recent systematic review of more than 25 studies of flu immunization

came to conclusions quite different than those recent front-page

headlines would suggest. The internationally recognized Cochrane

Collaboration (which accepts no money from the pharmaceutical industry)

did a systematic review of all randomized trials studying the

effectiveness of influenza vaccination and concluded that the evidence

does not support universal immunization of healthy adults.

 

This study found that the flu shot reduced the incidence of clinical

influenza on average by 6 per cent, but there was high variability in

effectiveness. There were not enough hospitalizations or deaths in the

data to come to any conclusions as to what kind of payback the vaccines

are delivering.

 

So the jury is still out on whether a flu shot for all Canadians is a

good use of scarce health-care dollars.

 

And here's our challenge to our public-health agencies eager to see us

all vaccinated. Set up the study. Randomize about 10,000 Canadians and

bring on the needle. We're ready to roll up our sleeves and do our part

if it is for a study that will help to answer the $125-million question

- but not otherwise.

 

Alan Cassels is a drug-policy researcher with the University of

Victoria. Jim Wright is a professor in the departments of pharmacology

and therapeutics, and medicine at the University of British Columbia.