Memory Cells may Have Kept H1N1 flu 2009 Mild
Scientists say memory cells may have kept H1N1 flu mild. According to researchers from Hong Kong, H1N1 flu 2009 never reached the severity predicted because of memory cells that break down related viruses.
Scientists say even though H1N1 flu 2009 was widespread it was milder than expected. The reason might be from memory cells that help break down the virus even when no antibodies are present, produced by exposure to influenza type A or seasonal flu.
"Our data suggest that individuals who were infected with seasonal human influenza A viruses previously or who received seasonal human influenza vaccines may derive benefit, at least in part, from the preexisting cross-reactive memory cytotoxic T lymphocytes to reduce the severity of pdmH1N1 infection even without protective antibodies. “
Scientists say memory cells have been shown to break down flu viruses in past studies, producing antibodies that provide some protection to related viruses.
Vaccines that protect from seasonal type A influenza, or having had seasonal influenza, may have been a factor that contributed to H1N1 flu being milder than predicted. Even though H1N1 flu was widespread, exposure to seasonal flu virus may have helped keep H1N1 flu mild.