# 3908
On the same day that the NIAID study comes out promoting the idea of increased childhood vaccinations to slow antigenic drift of flu viruses (see NIAID Scientists Propose New Explanation for Flu Virus Antigenic Drift ) we get blindsided by a new, contrarian study, that questions the wisdom of vaccinating kids against seasonal flu.
Helen Branswell, medical reporter for The Canadian Press, gives us a terrific overview of the controversy. Follow the link to read it in its entirety.
A hat tip to Crof on Crofsblog for posting this story.
Do seasonal flu shots impede little kids' ability to fight off pandemic flu?
By Helen Branswell Medical Reporter (CP)
TORONTO — Just when you thought the issue of seasonal and pandemic flu shots couldn't get any more confusing, European researchers are questioning whether it makes sense to vaccinate little kids against seasonal flu.
The scientists, from the Erasmus Medical Center in Rotterdam, the Netherlands, argue preventing small children from being infected by - and developing immune responses to - seasonal flu viruses might make them more vulnerable when a flu pandemic rolls around.
It's not clear the theoretical concern they raise is true. But other scientists counter that even if it is, it makes more sense to try to protect children from a threat they face every year than one they might face every few decades.
"The simple question is should we let young children suffer from a severe and potentially fatal but easily preventable illness, just because there is a theoretical possibility that withholding vaccination might result in a slightly less severe illness sometime in the future?" a pair of Finnish researchers retorted in a counterpoint published with the perspective piece, in the journal Lancet Infectious Diseases.
The study causing all of the commotion is from the Lancet:
doi:10.1016/S1473-3099(09)70263-4
Yearly influenza vaccinations: a double-edged sword?
Original Text
Rogier Bodewes DVM , Joost HCM Kreijtz PhD, Dr Guus F Rimmelzwaan PhD
Summary
Yearly vaccination against seasonal influenza viruses is recommended for certain individuals at high risk of complications associated with influenza. It has been recommended in some countries, including the USA, that all children aged 6—59 months are vaccinated against seasonal influenza. However, it has been shown—mainly in animals—that infection with influenza A viruses can induce protective immunity to influenza A viruses of other unrelated subtypes.
This so-called heterosubtypic immunity does not provide full protection, but can limit virus replication and reduce morbidity and mortality of the host. This type of immunity might be relevant to human beings when a new subtype of influenza A virus is introduced into the population, such as the new influenza A H1N1 virus responsible for the present influenza pandemic and the highly pathogenic avian influenza H5N1 viruses that are causing an ever increasing number of human infections with high mortality rates. Preventing infection with seasonal influenza viruses by vaccination might prevent the induction of heterosubtypic immunity to pandemic strains, which might be a disadvantage to immunologically naive people—eg, infants.
