Marking 20 years
of bold journalism,
reader supported.
Life

Would a Shot Really Stop it?

Flu vaccines are never a sure thing. This year less than half may work. Beyond the hype, when is a flu shot really worth it?

Lisa Johnson 8 Dec 2003TheTyee.ca

Lisa Johnson is journalist in Vancouver who specializes in science and the environment. She has reported for CBC Radio in Vancouver, Toronto, and Nelson, B.C.

image atom

TheTyee.ca

The message from health officials has been clear this fall. It's going to be a bad cold season, they say, "Get a flu shot or get the flu." Health Canada said the flu vaccine is 70 to 90 per cent effective. But this year, that's not the case.

The vaccine that was delivered to nearly one million people in B.C. wasn't made to protect against type of flu that's hit B.C. and the rest of Canada.


"The vaccine is not an ideal match for the current dominant strain [of flu virus]," says Dr. Bob Brunham, medical director of the B.C. Centre for Disease Control. The strain is called "A-Fujian," a variety of influenza A and one of the more deadly types of flu. 

At least five children in England have died from the virus, and lab tests have confirmed about 20 people in Ontario are infected with it. Hearing this news, Ontario flu shot clinics are reporting "record numbers" of people getting vaccinations to protect themselves from A-Fujian.


But instead of receiving a vaccine that's up to 90 per cent effective, experts estimate the vaccine may only help in 40-70 per cent of cases. While those numbers don't mean the vaccine is useless, they do inject some skepticism into the annual flu shot hype.


Always a few steps behind

In a way, the mismatch between virus and vaccine isn't surprising. Millions of virus generations pass between one flu season and the next, offering many opportunities for new strains to develop.

"It's an inherently unpredictable business." says Brunham.  Nevertheless, a lot of global health resources are poured into that business every year. The World Health Organization monitors influenza strains around the world with the help of a network of researchers. The WHO picks three strains to include in the vaccine, and most countries -including Canada--follow suit.


Brunham says the vaccines have to play catch-up with the mutating virus. "We always use last year's virus to vaccinate against this year's flu," he says. This season's vaccine was designed to combat the New Caledonia, Hong Kong and Panama strains of flu.


The  Fujian strain is a "close cousin" of the Panama strain, according to CDC lab tests. If the two viruses are similar enough, then people who were exposed to the flu last year -or who received this year's vaccine made for last year's virus--will have some protection against the bug. That's why Brunham estimates that the vaccine will still be over 40 per cent effective.


But Edda West of the Vaccine Risk Awareness Network (VRAN) says lab tests can't give strong enough evidence that the vaccine will help. VRAN is a non-profit group based in Nelson, B.C. that advocates for public education about vaccines across Canada. "No one has studied whether people who have had the vaccine are actually protected against the Fujian strain," says West. "That's an opinion," she says.

But Brunham says the spread of flu this year isn't as fast as a totally new, unrelated virus would be. He says a strain with zero similarity could cause a quick-spreading epidemic because there would be no immunity in the population. "But that's not the case here," says Brunham. "The Fujian strain is similar enough that there is some protection."


Maybe you don't have the flu


Even if the vaccine isn't 90 per cent effective, isn't "some protection" from a vaccine useful against an infection that hits so many people each winter? Maybe, but it's important to know that most of what we call the "flu" isn't influenza at all.


Anyone with aches, sniffles, fatigue and a sore throat this time of year will usually say they have the "flu." But studies show that only about 10 per cent of these cases are actually caused by the influenza virus.


"Influenza is the only infectious agent the flu shot works against," says Dr. Grant Stiver, a University of B.C. professor who studies infectious diseases at Vancouver General Hospital.


Stiver says the flu-like cases that aren't real influenza are caused by other viruses, such as adenovirus and parainfluenza virus. He says even doctors can't tell the difference between bona fide flu symptoms and ones caused by these other bugs. Only lab tests -and our immune systems--can distinguish them.

Overkill for 'minority illness'?

For West, that's reason enough to wonder why flu shots are so heavily promoted. "Why would anyone want to get a shot for such a minority illness?" she says.

A recent study on Ontario's flu vaccine program suggests the flu may indeed be minor -at least in terms of how many flu sufferers go to the emergency room. Ontario provides province-wide flu shots free of charge, in part to cut the number of emergency room visits by flu sufferers.


But the study shows that people with the flu only accounted for 1 in every 300 trips to the ER. And despite some $40 million dollars in annual funding, the flu shot program had no effect on the number of emergency room visits.


Still, some B.C. employers provide flu shots for their employees to prevent sickness and lost productivity in their workplace. On this score, studies show that the flu shot does help people get to work more often. But on average, the vaccine only buys 0.4 fewer sick days -or about 200 minutes--per employee each winter.

People who definitely need a poke

So where do all these numbers leave British Columbians who want to stay healthy this winter? Do you get a flu shot or not?

Brunham says the CDC still recommends flu shots for people who are covered by B.C.'s free flu shot program: seniors, health care workers, people with chronic illness, and anyone who comes in regular contact with those groups. "The vaccine is very safe, it's a great thing to get," says Brunham, who says he also gets a flu shot each fall.

But there are some costs. Money-wise, the shot costs about $20 for people who aren't covered by their employer or the provincial program. And Stiver says the flu shot makes some people sick for a day or more. "As vaccines go, it's well tolerated," says Stiver. But he says 10 per cent of people get a fever and soreness after the shot.

West says VRAN doesn't tell people whether they should get a flu vaccine or not. "The flu shot campaign kicks into high gear every year," says West. "We just want people to know the facts about vaccines to make their own choice," she says.

Lisa Johnson is a Vancouver-based journalist who specializes in health and science writing. She has reported for CBC Radio, the Georgia Straight, and UBC's Thunderbird.  [Tyee]

Tyee Commenting Guidelines

Comments that violate guidelines risk being deleted, and violations may result in a temporary or permanent user ban. Maintain the spirit of good conversation to stay in the discussion.
*Please note The Tyee is not a forum for spreading misinformation about COVID-19, denying its existence or minimizing its risk to public health.

Do:

  • Be thoughtful about how your words may affect the communities you are addressing. Language matters
  • Challenge arguments, not commenters
  • Flag trolls and guideline violations
  • Treat all with respect and curiosity, learn from differences of opinion
  • Verify facts, debunk rumours, point out logical fallacies
  • Add context and background
  • Note typos and reporting blind spots
  • Stay on topic

Do not:

  • Use sexist, classist, racist, homophobic or transphobic language
  • Ridicule, misgender, bully, threaten, name call, troll or wish harm on others
  • Personally attack authors or contributors
  • Spread misinformation or perpetuate conspiracies
  • Libel, defame or publish falsehoods
  • Attempt to guess other commenters’ real-life identities
  • Post links without providing context

LATEST STORIES

The Barometer

Do You Think Naheed Nenshi Will Win the Alberta NDP Leadership Race?

Take this week's poll