By Helen Branswell, The Canadian Press - Thursday, February 21, 2013 - 0 Comments
TORONTO – This year’s flu vaccine provided little protection to people 65 and older…
TORONTO – This year’s flu vaccine provided little protection to people 65 and older who got a shot, new data released by the U.S. Centers for Disease Control reveal.
The study estimates how well the vaccine did at preventing people from becoming sick enough to need to see a doctor — preventing “medically attended flu” in influenza science parlance. And the data suggest this year the vaccine didn’t perform very well for older adults.
It found that a flu shot cut an older adult’s risk of contracting a case of influenza A H3N2 that needed medical care by only nine per cent.
When the scientists calculated the overall effectiveness — the vaccine’s ability to prevent medically attended flu caused by both flu A and B viruses — the estimate was 27 per cent for older adults.
The findings are disappointing given the H3N2 component in this year’s vaccine is well matched to the viruses circulating. Paradoxically, the B component of the vaccine isn’t as closely matched to circulating viruses, yet it is performing better, according to the study.
Dr. Joe Bresee, a flu expert with the CDC, said older adults need to know that if they got a flu shot and they develop flu-like illness, they may have influenza and should see a doctor to determine if they should take antiviral drugs.
“We wanted to make sure that people knew that — especially if you’re elderly to know that — because we still want to communicate the fact that if you do get sick, get antivirals. And don’t assume just because you got the vaccine, that that flu-like illness you’ve got can’t be flu,” said Bresee, who heads the CDC flu division’s epidemiology team.
This type of study may actually overestimate the effectiveness of the vaccine, some experts say. It cannot capture a picture of what percentage of people got a shot and got the flu but didn’t see a doctor. Most people simply ride out a case of the flu in bed.
As well, it doesn’t account for people who become so sick they go directly to hospital, which would not be uncommon in elderly people with influenza.
The findings are an interim estimate, based on data gathered during the middle of the flu season. The researchers doing this work are continuing to gather data and will run a final analysis at the end of the season.
The numbers may change slightly in the final analysis; in this run-through, the overall vaccine effectiveness figure dropped to 56 per cent from 62 per cent in an analysis conducted in January.
But Bresee suggested that the current figures are likely a pretty accurate reflection of the vaccine’s performance in older adults.
“The nine (per cent) is going to change a little bit one way or the other,” he said in an interview from Atlanta.
“But the nine’s not going to become a 50, definitely, as we add data. I think we’re confident that the effectiveness against that A strain in the elderly is going to be quite low.”
Even in younger adults and children, the study suggests this year’s vaccine offered modest protection. Bresee described it as “moderate” and said it’s a word people in the flu world are starting to realize seems to apply to flu vaccine.
Even in young adults — the group which typically mounts the best immune response to flu vaccine — the performance of this year’s vaccine was not stellar.
In people aged 17 to 49, it cut the risk of medically attended flu by 52 per cent overall. But for the H3N2 component, the protection was only 46 per cent in this age group.
Dr. Danuta Skowronski, a flu expert with the British Columbia Centre for Disease Control, said the findings are consistent with Canadian and European vaccine effectiveness estimates released in recent weeks.
For Canada the H3N2 effectiveness rate was 45 per cent, she noted, while European investigators pegged the effectiveness against that component at 42 per cent.
By Rosemary Westwood - Monday, December 17, 2012 at 10:35 AM - 0 Comments
Mandatory immunization rules present a challenge
British Columbia’s front-line health professionals must either get the flu shot this year or wear a surgical mask in patient areas. Except it’s okay if they don’t. Such is the confusion in B.C. hospitals and clinics after the ministry of health watered down its controversial policy of mandatory flu shots for health workers who deal with patients.
The province originally announced the policy in August to combat low vaccine coverage among health workers. At the time, B.C.’s chief medical officer, Dr. Perry Kendall, said it would protect patients from contracting influenza, which causes more deaths than any other vaccine-preventable disease. An editorial in the Canadian Medical Association Journal praised the move, but B.C.’s major health unions fought it, arguing it infringed on worker’s rights and liberties.
On Dec. 4, the health ministry suspended the enforcement of the new policy for one year. That’s left “considerable confusion,” says Bonnie Pearson of the Hospital Employees Union, which helped negotiate the temporary compromise. Some employers are still telling workers to wear a special badge if they don’t get the shot, even though that part of the policy has been suspended, she says. Pearson argues a mandatory policy can have the opposite effect: “It’s that kind of a perverse ‘I’m not going to do it because you tell me I have to’ argument,” she says.
By Julia Belluz - Thursday, November 24, 2011 at 3:58 PM - 32 Comments
“… those who are so willing to inject mercury containing vaccines into people under the delusion that they are forwarding public health… should be required to submit the scientific evidence for their decisions.” — Flu vaccine statistics don’t add up, in the Nelson Star, 15/11/2011
In a world where paranoia and distrust of science abound, this op-ed in a local B.C. paper certainly fueled uncertainty around flu vaccines. In the piece, the writer suggests that public health officials and the media were deliberately misinterpreting data from a recent Lancet review about the flu shot by concluding that it’s effective for most people.
Science-ish poked around in the studies, and found a more nuanced story about the flu shot. Continue…
By Cathy Gulli - Monday, October 19, 2009 at 11:26 AM - 234 Comments
Everyone needs the H1N1 vaccine. Few plan to get it. What you need to know. What you need to do.
In a few weeks, every adult in Canada will decide if they (and their children) will get the ﬂu vaccine to protect against H1N1. At the best of times, it seems the decision of whether or not to get the seasonal ﬂu shot is tough to make. Only about one-third of Canadians do each year. Now, with the pandemic vaccine arriving in doctor’s ofﬁces in November, Canadians are being asked to get a second shot this fall.
But will they? Probably not. A recent poll shows that, as of the ﬁrst week of October, only one in three Canadians plan on getting the H1N1 vaccine, according to Harris/Decima. That’s down from 45 per cent in late August. Experts say this reﬂects the public’s growing apathy toward the pandemic in light of seemingly contradictory information about H1N1 (which is commonly referred to as swine ﬂu, even though it’s a combination of ﬂu viruses from pigs, birds and humans). People are being bombarded by “on the one hand” and “on the other hand” studies and recommendations. “There is confusion,” says Dr. Sarah Kredentser, president of the College of Family Physicians of Canada. “And I think it’s warranted confusion, because the messages keep changing.” Continue…