Flu and COVID infections appear to stop rising - but the respite may be short-lived

Well the good news for an NHS in crisis is that flu and COVID infections appear to have stopped rising.

But with people returning to work and school this week, the respite may be short-lived, say officials.

What's more, we've just seen the first UK data on a new COVID variant - CH.1.1, which is now the fastest-growing COVID strain in the UK.

Today saw the release of the first data on flu and COVID infections from the UK Health Security Agency since the week before Christmas.

It reveals hospital admissions for flu reached the most extreme "very high" level over the Christmas period.

But by 1 January, flu admissions had fallen rapidly back to "medium" levels. COVID admissions also declined.

The steep drop in flu could be due to various data quirks that occur over the holiday period, but according to the UKHSA, the fall probably indicates that the very rapid rise in both viruses has probably levelled off - for now at least.

Although people see family over Christmas, normal mixing in the workplace and schools will rise from now on and potentially bring a resurgence in infections. So today's data snapshot is no guarantee the extra pressure that respiratory viruses have put on the NHS will ease.

And then there's new variants of COVID.

Read more:
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There is concern over the XBB variant of Omicron that's grown very rapidly in the northeastern United States and in other parts of Europe. But so far, it doesn't appear to be taking off in the UK as fast.

XBB made up 5% of cases on 20 December, last week it was 7% of cases. However, since regular testing was ended it's hard for officials to estimate the variant's actual growth rate, with just a few hundred samples of it being collected so far each week.

But XBB is now joined by CH.1.1 which appears for the first time in the data above (in green). It first emerged last spring and is thought to have originated here in the UK from a previous Omicron variant called BA.2.75.

CH.1.1 stayed at such low levels it was of little interest. But in recent weeks it started to rise steeply and now makes up 18% of UK cases.

As with all previous Omicron offshoots, there's no evidence XBB and CH.1.1 viruses cause more severe disease.

However, their growth advantage means they could still pose a threat to a failing health service. Most spikes in COVID cases have been linked to the emergence of a new variant as it grows to replace the existing dominant strain.

If that were to happen this winter it could cause a very unwelcome source of further pressure on hospitals and care homes.