Officials are deploying surge testing in parts of south London after detecting dozens of cases of the South African variant, which appears to be more resistant to current vaccines.
About 44 cases have been confirmed, chiefly in the boroughs of Wandsworth and Lambeth, while a further 30 probable cases have also been identified, the Department of Health and Social Care (DHSC) said.
In what the department said was the “largest surge testing operation to date”, people over the age of 10 who live, work or travel through the area are being urged to take a Covid-19 polymerase chain reaction (PCR) test, in addition to biweekly rapid tests. Positive PCR test results will be sent for genomic sequencing at specialist labs.
All those who tested positive are isolating or have completed their isolation, and their contacts have been traced and asked to isolate, the DHSC said.
The first case in the cluster was identified in March. The strain, named B1351, has been classed a “variant of concern” as it appears to be more resistant to existing vaccines. It carries a mutation, E484K, which helps the virus evade the immunity conferred by past infection or vaccination.
South Africa suspended its use of the Oxford/AstraZeneca vaccine in February after the results from a small trial in young people suggested the jab prevented only 10% of mild or moderate disease caused by the variant. The UK, which is administering the vaccines by AstraZeneca, Pfizer and Moderna, has primarily relied on the Oxford-made jab in its rollout.
Dr Susan Hopkins, chief medical adviser for NHS Test and Trace, said the cluster of cases is “significant” and urged people to “play their part in stopping any further spread within the local community”.
She said that PCR testing is “now available for all”, encouraging everyone in the boroughs to get take a test even if they have no symptoms, pointing out that around a third of Covid-19 cases are asymptomatic.
“By taking part, you can protect yourselves and your loved ones and help us identify any possible new cases that would otherwise be missed, preventing further transmission and saving lives,” she said.
Surge testing has been deployed in several locations since the variant was first detected, with further testing rolled out in parts of Essex, Hampshire, Middlesbrough and Walsall among other areas in recent months.
A total of 544 cases of the South African variant had been identified up to 7 April across the UK, with all but 11 confirmed, according to Public Health England. This compares with 193,315 cases of the variant that was first discovered in Kent.