Early Canadian flu vaccine estimate finds solid H1N1 protection
The Northern Hemisphere's 2015-16 flu vaccine has shown significant protection against circulating 2009 H1N1 strains in Canada, according to an interim report today from Canadian researchers in Eurosurveillance.
Using a test-negative design, researchers in the surveillance system network found that adjusted vaccine effectiveness against the strain among all age-groups was 64% (95% confidence interval [CI], 44%-77%). For adults 20 to 64, protection was 56% (95% CI, 26%-73%).
Of 67 2009 H1N1 viruses that the investigators sequenced, 62 belonged to an emerging 6B subclade. The team concluded that this year's vaccine provides significant protection, despite evolution in circulating viruses.
For comparison, European researchers found 44% overall protection against 2009 H1N1 in their initial assessment in February, but they warned that the late start to the flu season reduced their sample size and made their prediction less precise.
An early estimate from the US Centers for Disease Control and Prevention (CDC) published a few weeks later found overall 51% protection against the 2009 H1N1 virus, which as in Canada and elsewhere in the Northern Hemisphere is responsible for the largest share of flu activity this season.
Mar 17 Eurosurveill report
Feb 11 CIDRAP News scan "Early European flu vaccine estimate finds lower protection against H1N1"
Feb 25 CIDRAP News story "CDC's early estimate finds this year's flu vaccine 59% effective"
China reports new H7N9 avian flu case
Chinese health officials today reported a new H7N9 avian flu infection, according to a translated report from FluTrackers, an infectious disease news message board.
The newly reported patient is hospitalized in the city of Longyan in Fujian province. No other demographic information was given. Regional officials have begun surveillance and initiated the district's emergency plan, according to the report.
The new case is part of a fourth wave of H7N9 activity in China and lifts the overall global total from the disease to 767 cases, according to a list maintained by FluTrackers.
Mar 17 FluTrackers post
FluTrackers H7N9 case list