New Vaccine Element Could Generate Better Protection From Avian Influenza

ScienceDaily (Sep. 18, 2008) — Current vaccines for influenza provide protection against specific seasonal influenza A strains and their close relatives, but not against more distant seasonal influenza A viruses and new avian influenza A viruses, such as H5N1, which still poses a real global health concern.

However, a team of researchers led by Tao Dong and Andrew McMichael, at Oxford University, United Kingdom, has now generated data that suggest adding a new component to vaccines for influenza might enable them to confer protection against a broad range of avian and seasonal influenza A viruses. In an accompanying commentary, Peter Doherty and Anne Kelso discuss in more detail how the data generated in this paper might be translated into a new and improved vaccine.

In the study, subsets of immune cells known as memory CD4+ and memory CD8+ T cells from individuals from the United Kingdom and Viet Nam were found to respond to fragments of proteins from both a seasonal influenza A strain and a strain of H5N1. Nearly all people tested had cells that cross-reacted between the seasonal influenza A strain and H5N1.

The authors therefore suggest that adding fragments of influenza proteins to current vaccines for influenza might boost memory CD4+ and memory CD8+ T cell responses towards both seasonal and avian influenza viruses, providing broad protection.

Journal references:

1. Lee et al. Memory T cells established by seasonal human influenza A infection cross-react with avian influenza A (H5N1) in healthy individuals. Journal of Clinical Investigation, 2008; DOI: 10.1172/JCI32460
2. Peter C. Doherty and Anne Kelso. Toward a broadly protective influenza vaccine. Journal of Clinical Investigation, 2008; DOI: 10.1172/JCI37232

Adapted from materials provided by Journal of Clinical Investigation, via EurekAlert!, a service of AAAS.