Annual Childhood Flu Vaccines May Interfere With Development of Crossresistance

From the 17 November Science Daily article

Vaccinating children annually against influenza virus interferes with their development of cross-reactive killer T cells to flu viruses generally, according to a paper in the November Journal of Virology.

In this study, first author Rogier Bodewes of Erasmus Medical Center, Rotterdam, The Netherlands and his collaborators collected blood samples from Dutch children with cystic fibrosis, who are vaccinated annually against influenza, and from healthy control children who are not vaccinated, and tested both sets of blood samples for the presence of virus-specific killer T cells. The majority of virus-specific killer T cells are directed to conserved viral proteins, that is, proteins that are very similar among different flu viruses, unlike the rapidly evolving, highly variable proteins which are targets of antibodies induced by influenza vaccines.

In unvaccinated children, the investigators found that the number of virus-specific T cells rises with age, while such an increase was absent in children vaccinated annually. In fact, vaccination appeared to interfere with induction of such killer T cells, says Bodewes….

…The research points up potentially conflicting policy outcomes. Annual flu vaccines are effective against seasonal flu, but could leave people more vulnerable to novel pandemics, says Bodewes, as induction of virus-specific killer T cells caused by childhood flu infection may reduce morbidity and mortality rates from pandemic influenza viruses.

Read the article

 

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