The 2018/2019 flu vaccine has been significantly more effective than last year, says a network headquartered at the BC Centre for Disease Control.
According to mid-season analysis performed by the Canadian Sentinel Practitioner Surveillance Network, this year’s vaccine has been 91 per cent effective against H1N1 influenza for children ages one through eight, and 72 per cent effective for the general population.
This is a huge increase in efficacy over last year’s vaccine, which was less than 20 per cent effective against the dominant influenza A (H3N2) for the general population.
“Vaccine effectiveness in general tends to be better against H1N1 viruses than the other kind of influenza A,” said Dr. Danuta Skowronksi, lead for the Influenza and Emerging Respiratory Pathogens Team at the BCCDC and the lead of the surveillance network.
“This year’s vaccine performed well in part because the H1N1 kind of influenza A virus has been dominating and because this year’s vaccine is a good match to that circulating virus.”
According to the BCCDC, the H1N1 virus tends to have a greater effect on children and non-elderly adults, whereas the H3N2 virus tends to be harder on seniors.
“A lot of children who weren’t born in the last few years will not have seen the H1N1 virus that was introduced during the pandemic in 2009 and has been circulating since then,” said Dr. Manish Sadarangani, a pediatric infection diseases doctor at BC Children’s Hospital. “So it’s likely they have lower immunity to the H1N1 than people who are older.”
While Dr. Sadarangani said October is the ideal time of year to get a shot, he added it’s not too late if you have yet to do so.
“There’s still a lot of influenza A and a lot of H1N1 circulating,” he said. “With the great vaccine effectiveness data that came out of the study published today, I would definitely encourage people to go out and get their flu shots.”
When asked about next year’s season, he said it’s impossible to predict what will be the dominant strain.