Why the UK could be headed for a flu ‘twindemic’ this winter

Last year’s warnings about a particularly bad flu season didn’t come true, but a previous more severe outbreak in Australia doesn’t bode well for the northern hemisphere.

To Claire Wilson

The UK, like several other countries, is ramping up its efforts to persuade at-risk groups, including those over 50. vaccinated against both influenza When COVID-19 in the coming weeks.

UK Health Security Agency (UKHSA) officials today launched fall vaccination campaigns against both respiratory viruses, warning that this winter is likely to be particularly bad for influenza.

At this point, some may have a sense of déjà vu. Similar claims were made 12 months ago, but the anticipated flu-covid-19 ‘twindemic’ never materialized.

But that doesn’t mean you shouldn’t believe this warning. Last winter, many people were more or less social distancing.

In England, as omicron began to surge in December, ‘Plan B’ rules were introduced, including mandatory facemasks in indoor public spaces and proof of vaccinations for entry into venues such as nightclubs. it was done.

There is also less social mixing in other ways, such as the prevalence of working from home.

Ultimately, this didn’t stop the Omicron surge, but the flu, which is less contagious than the coronavirus, was suppressed to very low levels.

Influenza hospitalizations in England peaked in one-sixth of the years before the pandemic.

During the average winter, 20-30% of people are exposed to the flu virus, and many have no symptoms. This means that, for the second year in a row, almost all of these normal exposures did not occur. As winter approaches this year, herd immunity to the flu will be far less than usual.

Social mixing could return to pre-pandemic levels as the UK has not announced plans to reintroduce restrictions this winter. It is believed that this will be the first season in three years that will allow

Australia’s experience over the past few months during the winter provides an indication of what will happen in the northern hemisphere. The peak number of cases is significantly higher than three years ago The covid-19 pandemic has started.

The main influenza variant that broke out in Australia this year is called H3N2, and previous studies have suggested its cause. A disease more serious than the typical seasonal fluThe strain was associated with slightly higher flu hospitalization rates in the UK six years ago.

Luckily, influenza vaccines soon to be available in the northern hemisphere contain the H3N2 virus in inactivated form.

This year’s Australian flu season not only peaked with more cases than average, it also spiked in May and June rather than July and August, and occurred earlier in the winter.

For this reason, UKHSA says it is important that everyone in the northern hemisphere who is eligible get vaccinated against influenza as soon as possible. “Better book as soon as possible” Steve Russellthe National Health Service’s director of vaccination and screening, said in a statement.

Covid-19 hasn’t gone away either. The latest figures from hospitals and the Office for National Statistics show cases are starting to rise again in the UK.

“This winter may see for the first time the effects of the so-called ‘twindemic,’ where both the novel coronavirus and influenza are in full swing,” said Russell.

The good news is that the covid-19 increase was not caused by a radically different coronavirus variant, but by some new subvariant of omicron. Bivalent vaccines offered in many countries contain Omicron components. In the UK, everyone given a booster must be given the bivalent version unless supplies run out.

The twin threats make it increasingly important for eligible groups to accept covid-19 boosters and flu vaccine offers, he said. Simon Williams at Swansea University, England.

“Public health campaigns must deliver clear and strong messages about the risks of influenza, not only to vulnerable people but also to the health system,” Williams says.