By Scott Strasser, February 12 2015 —
According to a study involving University of Calgary professor James Dickinson, the influenza vaccine for 2014–15 hasn’t been very effective. In some cases, it has actually increased the chance of getting the flu.
The study showed that the 2014–15 vaccine alone had a 43 per cent effectiveness against H3N2, this year’s dominant influenza strain.
People who received their flu shots in both 2013–14 and 2014–15 were 15 per cent more likely to get the flu than if they never got the shot.
“For the people who had the vaccine twice in a row, there was a less than zero per cent effectiveness [boost], meaning they might be a bit more susceptible to the flu than they otherwise would be,” Dickinson said.
Dickinson, who co-authored the study, said further research is needed to determine why the shot wasn’t effective.
“There are some guesses to do with how the virus mutated, but those have to be tested,” he said.
The study is part of an annual national program that measures the effectiveness of the influenza vaccine.
Dickinson said the study helps health organizations decide how to make future vaccines better.
“This is the third year in a row we’ve been able to do analyses mid-season,” Dickinson said. “Finding the problem this year means we can do better next year.”