Many people are at their peak of infectiousness at the very time that Sajid Javid has said they can now mix freely in society
There have been many changes to isolation rules in England but the science of how Covid-19 spreads has remained the same. During the first waves of the pandemic, people were required to isolate for 10 days after testing positive. This was subsequently changed to seven days, so long as the person had a negative lateral flow test on days six and seven. Although data is still being collected on the impact of this change, the isolation period has been cut again: today, the health secretary, Sajid Javid, announced that people with Covid will only need to isolate for five days, so long as they show two negative lateral flow tests by day six.
I’m deeply concerned about this. There is little scientific evidence to justify these reduced measures. Yes, some would argue that Omicron is mild compared to other variants, and does not result in massive hospitalisations. But a comprehensive review of research into 5,340 infected people around the world showed that the times at which these people were shedding the most virus, and were therefore most infectious to others, was between days three to six. The amount of virus each person shedded tailed off at days seven to nine. By day 10, no viable virus could be recovered from their respiratory tracts.
Sally Cutler is professor in medical microbiology at the University of East London
