Virus that caused flu pandemic dominates again

Young adults, beware. The swine flu responsible for the pandemic five years ago is once again the dominant strain in North America. This doesn’t mean we are in the midst of another swine flu pandemic, but it does mean that people of working age are once again hardest hit by the virus, which has been hanging around since 2009. So far, more than 60 per cent of people in the US who have caught severe flu this season, or died of it, are between 18 and 64 years old. This is similar to rates during the pandemic but double the number of severe cases in this age group in the past three winters, when the H3N2 virus – which is more likely to hit older people – was top dog in North America. Only about a third of severe cases in the US this year are in people over 65. Tom Frieden,...