September 25, 2009
[efoods]An unpublished Canadian study that suggests seasonal flu shots raise a person’s risk of catching swine flu is raising concern abroad and triggering changes to flu vaccine program schedules at home.
The data, referred to as “the Canadian problem” by some scientists outside this country, are reported to link getting a flu shot last year with double the risk of contracting swine flu this year.
The link, if real, is to mild disease. One person who has seen the study says it seems to suggest that those who got a seasonal flu shot were less likely to develop severe disease if they became infected than those who hadn’t received the shot.