Atishoo! But is that sneeze evidence of flu or just a bad cold? The symptoms of influenza infection can be hard to distinguish from those caused by other viruses that trigger the common cold. Chances are that if you鈥檙e 30 or over, it may be a cold. That鈥檚 the message from research showing that people aged 30 or more can expect just two bouts of flu per decade for the rest of their lives. Children and adolescents are likely to succumb once every other year.
鈥淲e don鈥檛 know if that鈥檚 a result of adults鈥� immunity, or because we mix less with other people when we鈥檙e older,鈥� says Steven Riley of Imperial College London, who was part of the team that carried out the work.
Riley and his colleagues screened blood samples from 151 people in Guangzhou, southern China, for antibodies to nine common H3N2 flu strains that circulated between 1968 and 2009. An algorithm then worked out the years in which each person had become ill.
Advertisement
From the profiles created, the researchers found that the number of infections decreased as people got older, as did the strength of their immune responses. 鈥淚t could mean, for example, that people should have different influenza vaccines for different stages of life,鈥� says Riley.
The results from China should be applicable elsewhere in the world, says Riley, as the flu strains studied are ones that circulate around the world every year. 鈥淗3N2 is very much a 鈥榡et-set鈥� virus that mixes globally very well,鈥� he says.
Journal reference: PLOS Biology, DOI:
