Health chiefs have remained tight-lipped about the number of new cases of the South Africa variant discovered since “surge testing” was urgently rolled out to more than half a million people on Monday.

Some 44 confirmed cases had been found in Lambeth and Wandsworth as of Monday night, with a further 30 probable cases, the DHSC said earlier this week. 

But more than two days later, the government’s official variant dashboard, which monitors these numbers, is still displaying data from April 7, while the Department for Health and Social Care could not answer any of HuffPost UK’s questions yesterday.

To make matters worse, the government has not held a coronavirus press conference since last week, well before the new outbreak and the lifting of restrictions on Monday, citing Prince Philip’s death on Friday as the reason. By contrast, just three cases of the Manaus variant at the beginning of March were reason enough for a dedicated press conference to be held.

The information blackout comes as more than half a million adults living in south London boroughs have been offered coronavirus tests. The figure includes 264,000 in Lambeth, 265,000 in Wandsworth, and 14,800 in the Rotherhithe ward of Southwark. A case of the variant has also been detected in Barnet, north London, which has been confirmed as unrelated to the other clusters.

Downing Street has insisted the outbreak is being taken “very seriously” and “strong measures” have been put in place to prevent it spreading.

Experts have claimed “none” of the vaccines are as effective against the variant – though studies still suggest that the jabs will prevent severe disease and death. 

Data up to April 7 suggests there had been 544 cases of the South Africa variant found in the UK in total, including 533 genomically confirmed cases and 11 probable ones.

Thousands of people queued up at pop-up testing facilities offering polymerase chain reaction (PCR) tests on Tuesday and Wednesday, and marshals said they had warned that waiting times could be up to two hours.

People aged 11 and over who live, work or travel through the affected areas were being urged to take a PCR test, on top of twice-weekly rapid testing.

Commenting on surge testing, Professor Anthony Harnden, deputy chair of the Joint Committee on Vaccination and Immunisation (JCVI), told Good Morning Britain: “From a vaccine point of view the South Africa variant is of concern.

“We know from studies that none of the vaccines are as effective against the South Africa variant – though the vaccines still prevent against severe disease and death even with the South Africa variant.

“The problem is, they may not protect against infection which allows infection to transmit, and if we allow transmission through the community in large numbers with high infection rates then we could see other variants emerging.”

Professor Kevin Fenton, London regional director of Public Health England (PHE), told BBC Radio 4’s Today programme: “We’re finding cases because we’re doing more genetic sequencing of PCR positive tests of coronavirus which we’re seeing across the city.

“And that is identifying a low prevalence, a low number of cases, but we are finding cases of the South Africa variant.”

He added that vaccines and surge testing are part of a “package of interventions” for managing life with coronavirus in future.

“As we begin to recirculate in society, we want to encourage everybody to get vaccinated,” Professor Fenton said.

“That certainly gives us additional protection. But we need to continue to practise our preventive measures, and we need to do the surge testing if we find variants in order to contain them.

“These are the package of interventions that we will need to be getting used to as we enter this new normal of living with Covid and managing our lives with Covid for the near future.”

Lambeth Council is understood to have worked round the clock to get the surge testing operation up and running this week, and it was expected to continue for a fortnight.

A spokesperson said: “In partnership with the Department of Health and Social Care and the NHS there are road side billboards across Lambeth and Wandsworth encouraging people to take a PCR test. We have shared the information with our elected councillors, MPs, GPs, hospitals, voluntary sector and community groups so they can inform and reassure their constituents, networks, clients and patients about this surge testing.

“There has been a meeting with our borough’s seven business improvement districts to help engage businesses.

“The council has produced a leaflet asking people to take a PCR test which is being distributed to every household and every business in the borough. The leaflet also contains details of Lambeth’s enhanced self-isolation offer to ensure people are able to self-isolate.

“This will be translated into the 12 main languages spoken in Lambeth.”

Meanwhile the government defended its decision not to hold a press conference, telling reporters on Wednesday there were “no plans” to do so this week, but that: “You’ll have seen that he did a [broadcast] clip yesterday [Tuesday] to update on [vaccine groups] 1 to 9, and the important progress we’re making so that the public have the information they need about this important public health issue.”