Experts Warn of Potentially Severe Flu Season Due to Unusual Virus Mutation
Flu arrives each winter, but this year, the scenario seems different. A flu virus mutation occurred unexpectedly over the summer, appearing to bypass some of our immunity. This has led to a flu season that began more than a month earlier than usual and involves a virus type historically known for severity. Concerns are rising as the NHS issues a 'flu jab SOS' to prepare for what could be a challenging winter. While there's complexity and uncertainty, leading experts have expressed that they would not be surprised if this turns out to be the most severe flu season in a decade. Professor Nicola Lewis, director of the World Influenza Centre at the Francis Crick Institute, mentioned, 'We haven't seen a virus like this for a while, and these dynamics are unusual. It does concern me, absolutely.' However, she emphasized that she's more worried than panicked.
Scientists meticulously track the evolution of influenza viruses, given their frequent mutations and the need to annually update the flu vaccine. This evolution follows a pattern known as 'shift and drift,' with mostly minor drifts and occasional significant shifts in the virus's structure. A significant shift was observed in June, with seven mutations identified in the H3N2 flu strain, leading to a rapid increase in cases. Professor Derek Smith, director of the Center for Pathogen Evolution at the University of Cambridge, explained that these mutations, appearing out of traditional flu season timeframes, are occurring in the northern hemisphere's summer.
The virus will likely spread globally, said Prof Smith. With children back in school by September and cooler weather setting in, flu cases began to rise. The mutations are suspected to help the virus evade some of the immunity individuals have built from past infections and vaccinations. Hence, the flu virus finds it easier to infect and spread, contributing to an earlier flu season in places like the UK and Japan.
If this mutated virus can spread with ease, it doesn't need winter conditions of closed, heated indoor spaces to start the flu season. 'We're miles ahead,' noted Prof Lewis, who predicts a strong flu season. The virus's estimated reproductive number, or R number, is 1.4 this year, compared to the usual 1.2, suggesting that 100 infected people would spread it to 140 others this year, instead of the typical 120.
Professor Christophe Fraser from the Pandemic Sciences Institute at the University of Oxford says, 'It's highly likely it's going to be a bad flu season, and it's going to happen quite soon; we're already well into it.' The expectation is a season potentially worse than the past decade's. Typically, one-in-five people contract the flu, but that number might increase this season, he warns. Uncertainty remains about these predictions. Australia experienced its worst flu season but not with the same H3N2 mutation we face. Children seem to spread the virus effectively in playgrounds, though their immunity is quite different from that of older generations exposed to numerous flu seasons.