The latest wave of Covid infections may have peaked in younger people, according to scientists monitoring the pandemic.
Infection rates appear to be “plateauing” in adults aged 18-55 but are continuing to increase in older groups, analysts from Imperial College’s React study said.
Case rates in England are the highest they have ever been, and the two variants of Omicron – BA.1 and BA.2 – have caused twin peaks in the pandemic – one in January, and another in March, the data suggests.
Professor Paul Elliott, chairman in epidemiology at Imperial and director of the React programme, said the rates in younger groups “seem to be coming down” and “can’t go up forever”.
However, prevalence is increasing in the oldest age groups – those most likely to suffer from severe illness due to Covid - and hospital admissions in England have also been going up.
According to the study: “The high and increasing prevalence in older adults may increase hospitalisations and deaths despite high levels of vaccination.”
Professor Christl Donnelly, Jameel Institute, Imperial College London, and Department of Statistics, University of Oxford, said: “It’s still the case that if you see more infection, you would expect, even if it’s a very small proportion of those, to see more of the severe outcomes.
“So we don’t yet know when we’ll see a peak in the oldest age group – the 55 plus – and because those people are at higher risk of severe outcomes, that is a particular worry.
“It is possible if the prevalence continues to go up, that you will see further increases in the severe outcome rates.”
From March 8 to March 31 there was a prevalence of 6.37 per cent compared to 4.41 per cent in January.
The study, which has been published as a preprint, said: “There are worrying signs of increasing hospitalisations and deaths due to Covid-19 in England during March 2022, which may reflect the very high and increasing rates of infection, particularly in older people.
“These trends in England may presage what might be expected in the USA and other countries as BA.2 takes hold as the predominant variant worldwide.”
The latest data from round 19 will be the last from the React study, which has been running since May 2020.
However, the experts warn that ongoing surveillance is needed to monitor severe outcomes from the disease and to track new variants as they emerge.
Professor Paul Elliott, director of the React programme, and chairman in Epidemiology and Public Health Medicine, Imperial College London, said: “It is really important that there is continued surveillance looking for these new variants, and I believe that will be the case.
“As part of the ongoing surveillance of Sars-CoV-2 Covid-19 there is going to be a sequencing facility looking nationally at these variants and picking them up as they appear in the population.”
