Nu när det diskuteras svininfluensavaccinering igen finns det skäl att påminna om den kanadensiska studien från hösten 2012 som visar att de som fick svininfluensavaccin 2009 fick ökad risk att drabbas av svininfluensa än ovaccinerade. Studien avfärdades först av skeptiker som ett lokalt fenomen i Kanada, men uppföljande studier antyder att det var något fel på vaccinet som används internationellt.
A strange vaccine-related phenomenon spotted at the start of the 2009 flu pandemic may well have been real, a new study suggests.
Canadian researchers noticed in the early weeks of the pandemic that people who got a flu shot for the 2008-2009 winter seemed to be more likely to get infected with the pandemic virus than people who hadn’t received a flu shot.
Five studies done in several provinces showed the same puzzling and unsettling results. But initially research outside of Canada did not, and the effect was dismissed as “the Canadian problem.”
But a new study suggests the findings may indeed have been real.
“The findings that we show are consistent with the increased risk that we saw in the human studies,” Ms. Skowronski said.
She said that in the time since the pandemic, researchers in other countries have reported a similar interaction.
The reason for the effect is unclear, and Ms. Skowronski urged other research groups to take up the question. She said it is important to get to the root of what happened, before the next pandemic.