<Co-author Jim Wright is head of Therapeutics Initiative and a member
of the Cochrane Collaboration. Zee>

"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."

Universal flu shots: the $125-million question

By ALAN CASSELS and JIM WRIGHT
Globe and Mail Update
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.

~~~~~~~~

*Zee ed: Wright is also the head of Therapeutics Initiative and a
member of the Cochrane Collaboration.
*Therapeutics initiative
www.ti.ubc.ca