Reinfections should be included in Covid figures for the UK as soon as possible, scientists have said, amid warnings that up to 15% of Omicron cases could be people who have had coronavirus before.
현재, daily Covid case figures – which reflect the number of infections picked up by testing – do not include reinfections for all countries of the UK.
While figures for Wales do include multiple cases for the same person, provided the positive tests are more than 42 days apart, this is not the case for England, Scotland or Northern Ireland.
However scientists have said that with the proportion of cases that are reinfections growing, such figures should be urgently updated.
“The reinfection rate was fairly low with Delta, but is higher now, both because prior infection provides little protection against Omicron, and there is a bigger pool of people with prior infection,” said Prof Sir David Spiegelhalter, a statistician at the University of Cambridge.
According to a report released by researchers at Imperial College London last month, the risk of reinfection with Omicron is more than five times higher than with Delta.
Speaking on the Today programme on Tuesday, leading epidemiologist Prof Neil Ferguson of Imperial College said 중에서 10% 과 15% of Omicron cases are reinfections.
The figure chimes with data released by the UK Health Security Agency (UKHSA), which found that of 116,683 people identified as having an Omicron infection in England between 1 November and 18 December last year, 11,103 – or 9.5% – had previously tested positive for Covid more than 90 며칠 전에, and hence would be identified as being reinfected.
The Guardian understands that reinfections were not included in the case figures published on the government’s dashboard at the start of the pandemic as it was uncertain at the time whether it was possible to be reinfected and, if it was, the interval between infections.
Tim Colbourn, professor of global health systems, epidemiology and evaluation at University College London (UCL), said the case data should now be updated.
“I think reinfections should be added to the dashboard as soon as possible as they will be a growing proportion of cases going forwards,”그는 말했다. “10-15% now sounds plausible and I’m sure the [proportion] will increase over the coming weeks as immunity from prior infection and vaccination wanes.”
Prof Christina Pagel, director of UCL’s Clinical Operational Research Unit, agreed that the proportion of all Covid cases that are reinfections will continue to grow, although the rate of rise is going to be modest now that Omicron is the dominant variant in the UK and the lower reinfection rates with Delta are no longer part of the overall case picture.
Pagel added that in order to understand how quickly an immune-evasive variant is spreading, it is important to include reinfections.
“As more and more people get infected, given current policies, over the longer term it’s going to be rare to find someone who’s never had Covid," 그녀가 말했다, although she added many people who have had an infection will never have had a test.
The Guardian understands the UKHSA is planning to include reinfections in case data from the end of the month, though Pagel – who is not involved with the dashboard –said the task is not simple.
“My understanding is that most of the complex, interlinked data tables that underlie the dashboard need to be changed to include reinfections and that is just a massive job," 그녀가 말했다.