Infectious Disease News has posted a report of a paper, “H1N1 pandemic less severe among adults with history of flu.” The paper suggests that people with preexisting antibodies to different H1N1 strains had more immunity to swine flu H1N1 than those without. Getting a flu infection (whether or not you actually get sick… since the majority of people with influenza infections show few if any symptoms) leaves you with long-lived antibodies, and many more of them, than someone has who got vaccine. And they protect against similar strains, which flu vaccine usually fails to do.
This might explain the data from Canada and Hong Kong (that I have blogged about several times) which showed that receiving flu vaccine in 2008 led to almost double the likelihood of getting sick from swine flu in 2009. In other words, the unvaccinated from the previous flu season fended off swine flu much better than the previous season’s vaccinated people did.
This means that catching the garden variety flu could protect you in future from the much-anticipated, threatening Pandemic Flu. And the protection could be expected to last for many decades. Vaccine protection only lasts months, or a year or two. Maybe your body makes lemonade out of flu lemons.
UPDATE: Apparently this article, in French, suggests the same thing:
The irremediable ageing of the world population, the aged-related increasing in the prevalence of infectious diseases the fear of any influenza pandemic rife have recently led the European Union Geriatric Medicine Society (EUGMS) et the International Association of Geriatric and Gerontology European Regions (IAGG-ER) of establishing vaccine recommendations dedicated to individuals aged of 60 years or above and promoting a life-course vaccination programme. This approach is mainly motivated by the herd immunity-associated effect on the epidemiology of infectious diseases observed within the adult and old adult population. This review (1) after a presentation of the concept and its demonstrated beneficial effects; (2) will detail that herd immunity acts with adverse effects on the epidemiology of the infectious diseases in the adult and aged individual population; (3) in order to demonstrate that maintaining a vaccine pressure in every age groups is imperative.