Influenza vaccines should be optimized to better target influenza surface protein called neuraminidase (NA) for broad protection against diverse influenza strains, reports study published in Cell.
Current seasonal influenza vaccines mainly target a different, more abundant influenza surface protein called hemagglutinin (HA). However, because influenza vaccines offer varying and sometimes limited protection, scientists are exploring ways to improve vaccine effectiveness. The new research builds on previous studies of NA and was conducted by a team of scientists including investigators from the Centers of Excellence for Influenza Research and Surveillance (CEIRS) program, which is organized and funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.
Investigators analyzed blood samples from people vaccinated against influenza and people diagnosed with either the 2009 H1N1 influenza virus or H3N2 influenza viruses. The volunteers were recruited for this study or had taken part in prior influenza research studies. The analyses indicate that influenza vaccines rarely induce NA-reactive antibodies, whereas natural influenza infection induces these types of antibodies at least as often as they induce HA-reactive antibodies. Additional studies in mice reinforced the human data, indicating that current influenza vaccines do not induce NA-reactive antibodies efficiently.
In this regard, NIAID is supporting research to characterize NA responses in infected and vaccinated individuals and to determine the mechanism of action of NA protection. NIAID also supports "NAction!" a CEIRS working group that identifies knowledge gaps in our understanding of NA and sets NA research priorities for improved influenza vaccines. These efforts contribute to NIAID's larger plan to develop a universal influenza vaccine--a vaccine that can durably protect all age groups against multiple influenza virus strains.