Flu in England is arriving earlier than usual this year, experts have warned. Although the UK Health Security Agency (UKHSA) reports that flu levels are currently low, several indicators suggest an upward trend.
These indicators include the proportion of positive tests and the number of consultations with general practitioners for flu-like illnesses. The number of attendances at emergency departments for such symptoms is above the levels expected at this time of year. UKHSA has reported that flu activity in September was higher than in the same period in the previous four winters, with growth trends continuing from August.
Professor Sir Andrew Pollard, director of the Oxford Vaccine Group, has stated that there is one simple measure for those at risk due to age or existing health conditions: to vaccinate as soon as possible and before peak transmission is reached. He highlighted that while vaccination benefits everyone, free vaccines are available only to children and those in at-risk groups. Those who do not qualify for a free vaccine through the NHS may be able to obtain one free of charge through their workplace, and vaccines are available privately to anyone who can pay. Private flu vaccination costs around £20 in most high street pharmacies, while some retailers offer vaccination for less than £10 as part of membership schemes.
Pollard pointed out that an early flu season does not necessarily mean a poor season. "We do not know for certain why the timing of appearance varies each year," he said. He believes the early rise is due to a combination of factors, including weather, the specific virus strain circulating and its ability to spread, population immunity to the circulating strain, and aspects of behaviour, such as the number of close contacts people have.
Antonia Ho, professor of virology at the University of Glasgow, said that it is important to vaccinate as soon as possible, as the vaccine takes several weeks to provide full protection. She added that the early rise in cases could indicate a more intense flu season overall, as the earlier start is linked to a longer period of transmission in the community and a higher cumulative number of cases. However, the timing of the appearance does not determine the severity of the season, she noted.
UKHSA data indicates that the rise in flu is driven by cases among 18 to 24-year-olds, and that two subtypes of flu A are circulating in England: H1N1 and H3N2. Ho stated that the flu vaccine covers both subtypes, as well as influenza B. UKHSA has noted that the H1N1 subtype appears to have changed slightly, with the strain having drifted from the one used to make this year's vaccine. Ho believes it is too early to say whether this will affect the efficacy of the vaccine.
According to UKHSA data, the programme in England last winter, despite the flu season starting earlier than usual, is estimated to have prevented 100,000 hospital admissions and 7,000 deaths. John Tregoning, professor of vaccine immunology at Imperial College London and author of Infectious: Pathogens and How We Fight Them, noted that the previous year was a good example of when the flu season also started early, but people then changed their behaviour and went to get vaccinated, after which the number of cases fell.
Experts have called on those eligible for the COVID-19 vaccine to be vaccinated, as UKHSA data indicates a rise in COVID levels. Tregoning highlighted the importance of vaccination against respiratory syncytial virus (RSV). Ho added that although vaccination against respiratory diseases is important, people can take additional measures if they start to feel unwell. "If you have flu-like symptoms, ideally stay at home, maintain good hand hygiene and avoid contact with others," she said.
