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expert reaction to news reports that ‘surge testing’ is to be rolled out in areas of the UK after cases of the ‘South African variant’ were found with no known links to travel or previous cases

Media reports state that urgent COVID-19 testing is to be rolled out in parts of England after several people with no travel links were found to have caught the variant discovered in South Africa.


Dr Julian Tang, Honorary Associate Professor, Respiratory Sciences/Clinical Virologist, University of Leicester, said:

“The spread of this South African B.1.351/501Y.V2 (N501Y/E484K/K417N) variant in the UK from those with no travel history is not surprising and was somewhat inevitable – once we heard about the identification of some imported cases a few weeks ago in the UK.

“This is because we know that this SARS-COV-2 virus transmits very effectively pre-symptomatically – and there will be a small proportion of truly asymptomatic cases for every symptomatic case cluster of this virus.

“So for every case we identify, there may be many others infected (especially with a more transmissible variant) depending on the amount of pre-symptomatic/asymptomatic contacts that have occurred – prior to someone testing positive for this South African variant.

“Rapid testing to identify other cases and enhanced isolation for the infected and quarantine for their close contacts – may be difficult to enforce in a current national lockdown.

“But so far, there is no definitive evidence that this South African variant is causing more severe disease than the UK or other previous variants.

“The main risk is for the South African variant to transmit more efficiently to cause more infections that may overwhelm the NHS in those areas – so the current messaging – to stay home where possible, wear masks properly and maintain strict social distancing is still important.

“Although in vitro studies indicated a possible 6-fold reduction in vaccine efficacy for the S gene target, this is likely the worst case scenario and a combination of vaccine plus natural immune responses to all the other viral proteins may well reduce the spread of this virus in the population better than these in vitro studies suggest.”


Prof Lawrence Young, Virologist and Professor of Molecular Oncology, University of Warwick, said:

“The South African virus variant was originally detected in swab samples from October 2020 and fuelled the second wave of infection in South Africa becoming the dominant virus in the Eastern Cape and Western Cape provinces.

“It has a change in the spike protein in common with the UK variant which increases the stickiness of the virus making it more contagious. The South African variant also has other changes in the spike protein which appear to provide some escape from immune recognition – it prevents virus infection from being blocked by certain monoclonal antibodies and may contribute to a reduction in the effectiveness of current vaccines. This possibility is supported by recent data from both the Novavax and Janssen vaccine trials which show significant reductions in the ability of the vaccines to protect from disease in South Africa vas the UK or USA.

“There is also concern that the South African variant might be able to more efficiently re-infect individuals who have previously been infected with the original form of the virus. Whatever changes have occurred in the South African or any other virus variant, standard measures to restrict transmission (hands, face, space) will prevent infection. Improved surveillance (testing, tracing and isolating) will limit the spread of the South African variant.”


Prof Rowland Kao, Professor of Veterinary Epidemiology and Data Science, University of Edinburgh, said:

“The identification of cases of the SA variant in people with no obvious travel links (either travel themselves, or links to other known cases) suggest that, at the very least, they were infected while in the UK – i.e. there is evidence of local transmission. As only 5% of cases are tested to determine if they are the variant, there is a high probability that further local cases are in circulation – making it more difficult at the spread of the variant can be contained. Surge testing, i.e where all residents will be offered a PCR test via post will aim therefore to identify variant clusters and extent of spread, but is highly dependent on individuals taking up those tests, as it remains a voluntary activity. As there is some evidence that current vaccines may be at least somewhat less effective against this variant, slowing its spread via surge testing and maintaining travel restrictions to prevent it jumping to other areas of the UK (if it has not done so already) will be important to keep COVID-19 infections continuing downwards at its current trajectory.”


Dr Andrew Page, Head of Informatics, Quadram Institute, said:

“The variant being found to have infected some people with no travel history or link to known cases indicates community transmission rather than traveller associated transmission. My team have detected 3 cases in Norfolk, but we were able to trace all back to travel or contacts of travellers to SA.

“This variant can only be identified currently by genome sequencing. COG-UK sequences about 5-7% of all positive cases in the UK so it would have been identified by prospective surveillance.

“This variant is thought to be more infectious, but not more lethal. The Novavax trial indicates that their vaccine is less effective against this variant.

“Through ‘surge testing’ it is hoped to identify as many cases as possible, rapidly sequence them, and halt the community transmission whilst the outbreak is still small and in 1 geographical area.”


Prof Jonathan Ball, Professor of Molecular Virology at the University of Nottingham, said:

“We know that some coronavirus variants might be less easily killed by antibodies raised against some of the existing vaccines, but the levels of immunity are hopefully still sufficient to prevent serious disease. But we can’t be certain that vaccine immunity might not be adversely impacted, especially after a single dose, which is why it is important to try to prevent these variants from spreading widely. That will mean effective social distancing and identifying where the variants are currently circulating, so we can stop them in their tracks through effective testing, track and trace and isolating infected individuals.”


Dr Simon Clarke, Associate Professor in Cellular Microbiology, University of Reading, said:

“The presence of the ‘South African’ variant of the Covid-19 coronavirus in the UK has been recorded previously but has ultimately been linked to travel there.  This variant not only appears to spread rapidly, but there is emerging evidence to suggest that it is less susceptible to immunity induced by the current crop of vaccines.  The discovery of a handful of cases with no links to travel to Africa, indicates that it might be more widespread in the community than previously thought.

“Detecting this is a success story for the UK’s coronavirus genome sequencing programme.  This spread, even if small in scale, needs to be brought under control quickly, so Public Health England’s house-to-house checks, and intensive testing are the right thing to do.  Anyone testing positive for the coronavirus must isolate to stop the spread.”






Declared interests

Dr Andrew Page: “my group is part of the COVID-19 genomics consortium (COG-UK) so it is likely our consortium identified these cases; I’m a member of the SAGE Social Care Working Group.”

Prof Jonathan Ball: “No COIs.”

None others received

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