Via Metro, a report by Helen Branswell of The Canadian Press: This year's flu shot offered good protection. Excerpt:
This year’s flu shot offered substantial protection to people who received it, new Canadian data suggest.
The vaccine appeared to be about 71 per cent effective against all flu strains, and 74 per cent effective against H1N1, the strain responsible for more than nine in 10 of all confirmed flu infections this year in Canada, the study says.
The research measured how effective the vaccine was at preventing what’s called medically attended influenza — infections where the person was sick enough to seek care from a doctor or a clinic.
The effectiveness rate was significantly better than that seen in a similar study conducted last year by the same group of researchers.
“I think 74 per cent is pretty good, actually. And it’s certainly better than what we measured last year for the H3N2 that was dominating,” said Dr. Danuta Skowronski, an influenza expert at the British Columbia Centre for Disease Control in Vancouver.
In fact, the U.S. Centers for Disease Control estimates that flu vaccine cuts the risk of infection by between 50 to 70 per cent, putting this year’s vaccine at the high end of the effectiveness one might expect from a flu shot, especially one that does not include an adjuvant or boosting compound.
Canada used vaccine with adjuvant in the 2009 pandemic; the vaccine effectiveness was calculated about 93 per cent then. But adjuvants are not used in seasonal flu vaccine in Canada.
The results released Thursday were an interim estimate, calculated in time to help inform the experts who will meet at the World Health Organization later this month to select the viruses that should go into flu vaccine for the 2014-15 Northern Hemisphere winter.
Skowronski said she and her colleagues — from B.C., Alberta, Manitoba, Quebec and Ontario — continue to gather data and will issue a final analysis at the end of the flu season.