Annual childhood flu vaccines may interfere with development of crossresistance

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 , that is, proteins that are very similar among different , unlike the rapidly evolving, highly variable proteins which are targets of antibodies induced by .

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.

“Vaccinated children with [] will develop lower cross-reactive virus-specific CD8+ T cell responses than unvaccinated children,” says the study.

“Most countries recommend annual flu vaccination of certain high risk groups to protect against seasonal influenza,” says Bodewes. “Furthermore, some countries recommend annual influenza vaccination of all healthy children more than six months of age.”

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. Referring to the paper, he says that the findings “highlight the need for the development and use of universal influenza A virus vaccines for children, especially in light of the pandemic threat of avian influenza A/H5N1.” Nonetheless, he says that efforts to develop such vaccines have for several decades been stymied by the sheer complexity of targeting inner proteins.

More information: R. Bodewes, P.L.A. Fraaij, M.M. Geelhoed-Mieras, C.A. van Baalen, H.A.W.M. Tiddens, A.M.C. van Rossum, F.R. van der Klis, R.A.M. Fouchier, A.D.M.E. Osterhaus, and G.F. Rimmelzwaan, 2011. Annual vaccination against influenza virus hampers development of virus-specific CD8+ T cell immunity in children. J. Virol. 85:11995-12000.

add to favorites email to friend print save as pdf

Related Stories

NIH experts describe influenza vaccines of the future

Nov 17, 2010

In a review article appearing in the New England Journal of Medicine, scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, examine research under way to ...

Human trials of universal flu vaccine begin

Sep 08, 2008

Clinical trials of a new vaccine that could protect against multiple types of flu are beginning at Oxford University. If successful, the ‘universal’ flu injection would transform the way we vaccinate against ...

Bird flu vaccine protects people and pets

Oct 20, 2008

A single vaccine could be used to protect chickens, cats and humans against deadly flu pandemics, according to an article published in the November issue of the Journal of General Virology. The vaccine protects birds and ma ...

Recommended for you

Asthma drug may help those with chronic hives

9 hours ago

(HealthDay)—A drug already used to treat moderate-to-severe allergic asthma appears to offer relief to people with chronic hives who haven't been helped by standard medications, new research suggests.

Study compares deep vein thrombosis therapies (Update)

11 hours ago

Patients who have a clot in their legs and are considering whether to be treated with traditional blood-thinning medication or undergo a minimally-invasive catheter-based clot removal procedure should feel comfortable that ...

Automated models can identify acute back pain in EMRs

13 hours ago

(HealthDay)—Administrative data models can discriminate acute low back pain (LBP) from nonacute cases in electronic medical records (EMRs), according to a study published in the June 15 issue of Spine.

User comments