Findings in a recent study suspect that the 2009 flu endemic in Canada could have been due to flu shot. Study researchers, led by Vancouver's Dr. Danuta Skowronski, an influenza expert at the B. C. Centre for Disease Control, asserted that initially believed reason for the epidemic could possibly be true.

The researchers compared the sufferers of the outbreak with the data revealing the people, who were vaccinated against flu for 2008-09 winter. It was discovered that those of who received the flu shot accounted for the majority of the people infected.

So far five different studies have been done in several regions, which provided with similar results. However, the initial study, just after the epidemic emerged with results, which had no mention of the flu shots. However, this study affirmed that the previous findings were real.

The researchers carried out a series of experiments on 32 ferrets, of which half were subjected to 2008 flu vaccine and other were given placebo injection. The researchers were not aware which ferrets were vaccinated with the flu shot.

After sometime, all ferrets were discovered to have been infected by H1N1 virus. Those of who were vaccinated were sicker. "The findings are consistent with the increased risk that we saw in the human studies", Skowronski said.