The largest surge testing operation so far is taking place in areas of south London after more than 70 confirmed or probable cases of the South African variant of COVID-19 were detected.

The government says dozens of people are isolating or have completed their isolation after contracting the variant, B.1.351, and the cluster of infections is believed to be “significant”.

NHS Test and Trace is providing extra testing and genomic sequencing, mostly in the boroughs of Wandsworth and Lambeth.

There have been 44 confirmed cases and 30 probable cases predominantly found there.

People aged 11 and over who live, work or travel through those areas are being urged to take a COVID-19 PCR test, on top of using twice-weekly rapid testing.

It comes as scientists in Israel said the variant is able to “some extent break through” the Pfizer vaccine’s protection.

The Department of Health and Social Care said it is the “largest surge testing operation to date” in south London aimed at suppressing any possible new cases of the variant.

Extra testing sites will be made available and positive results from PCR testing will be sent for genomic sequencing at specialist labs.

Please use Chrome browser for a more accessible video player

It said all those who have tested positive for the variant, with the first case in the area being found in early March, are isolating or have completed their isolation, and their contacts have been traced and asked to isolate.

Facilities offering asymptomatic PCR testing have been deployed at Wandsworth Town Hall, Tooting Leisure Centre and the University of Roehampton, and further testing sites will be opened during the week.

Vauxhall MP Florence Eshalomi tweeted: “It is important for everyone over 11 across Lambeth to get a COVID PCR test ASAP – we have to keep safe and help stop the spread of the virus.”

It is important for everyone over 11 across Lambeth to get a COVID PCR test ASAP – we have to keep safe and help stop the spread of the virus. There are sites across the borough including at @stjohnswaterloo where you can pick up a home test. Please stay safe #COVID19 https://t.co/cfuQnjKP9h

Dr Susan Hopkins, chief medical adviser for NHS Test and Trace, said the cluster of cases is “significant”.

“It’s really important people in the local area play their part in stopping any further spread within the local community,” she said.

“PCR testing is now available for all and I would strongly encourage everyone, whether they live, work or travel through the boroughs, to get tested even if they don’t have any symptoms of coronavirus.

“Around one in three people with COVID-19 don’t show any symptoms.

“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.”

The Israeli study compared nearly 400 people who had tested positive for COVID, 14 days or more after they received one or two doses of the Pfizer vaccine, against the same number of unvaccinated patients with the disease.

The South African variant, B.1.351, was found to make up about 1% of all the COVID-19 cases across all the people studied, according to the study by Tel Aviv University.

Subscribe to the Daily podcast on Apple Podcasts, Google Podcasts, Spotify, Spreaker

But among patients who had received two doses of the vaccine, the variant’s prevalence rate was eight times higher than among the unvaccinated – 5.4% versus 0.7%.

This suggests the vaccine is less effective against the South African variant, compared with the original coronavirus and a variant first identified in Britain, the researchers said.

Related posts:

Man charged over online racial abuse of Premier League footballer British troops battle sandstorm to seize Islamic State weapons cache ‘Houses were shaking’: Neighbours in disbelief over fatal explosion in Lancashire street Four arrested over video ‘showing antisemitic abuse being shouted from car in north London’ Two children killed in crash on M1 near Milton Keynes Mental health hospital was closed after CCTV exposed staff being abusive towards patients Corbyn joins Assange supporters as US appeal against decision not to extradite WikiLeaks founder UK reports more than 100 coronavirus deaths for second day in a row Raducanu’s win could be most unexpected British sporting story ever UK set to have one million Omicron infections by end of December – but booster jabs effective, says UKHSA Prince Andrew accused of ‘victim blaming’ over demand for accuser’s mental health records Ruth Davidson says mental health history meant she almost did not run as Scottish Tory leader