The reason behind mildness of 2009 H1N1 pandemic
SiFy News
2010-06-19 15:50:00
Researchers from Hong Kong have unveiled a new theory to explain why swine flu infections in 2009 turned out to be so mild.
And they have said that prior exposure to seasonal influenza A, either infection or vaccination, may induce a cross-reactive immune response against the pandemic virus.
Although the outbreak of human H1N1 in 2009 spread to pandemic proportions, the illness was considered mild in most patients compared to seasonal influenza.
Currently available seasonal flu vaccines do not offer cross-reactivity to pandemic H1N1 in any age group, which suggests that individuals previously infected or exposed to seasonal influenza A viruses may have memory cell-induced cross-protection to pandemic H1N1.
