By Adam Cresswell, Health Editor
A leading flu expert has called for a rethink of flu vaccine policy, in the light of evidence suggesting people vaccinated against seasonal flu shortly before swine flu swept the globe had a greater risk of serious illness from the new strain.
Peter Collignon, professor of infectious diseases and microbiology at the Australian National University, said evidence was mounting to suggest that instead of protecting people from dangerous new flu types, seasonal flu vaccines may increase the danger, at least for those not considered at high risk due to other conditions.
Evidence from Canada, Hong Kong and some other countries suggested people who were infected with “normal” annual flu experienced a broader immunity over ensuing months than the protection conferred by vaccines.
Although temporary, this broader immunity appears to have offered some protection against newer flu strains – a protection not felt by those who had not been infected with seasonal flu because they had previously had the vaccine.
While the effect seems to be temporary – possibly just months – Professor Collignon said the evidence was troubling enough to warrant a review.
“That’s the opposite of what we expect vaccines to do – we expect vaccines to decrease your risk (of getting flu) by about 80 per cent, not increase it,” he said.