The chief medical adviser to the UK Health and Security Agency has warned that a newly identified Covid-19 variant in southern Africa is the “most worrying we’ve seen”, with transmission levels not recorded since the beginning of the pandemic.
Dr Susan Hopkins said the R value, or effective reproduction number, of the B.1.1.529 variant in Gauteng in South Africa, where it was first found, was now 2. For an R of anything above 1, an epidemic will grow exponentially.
She voiced her concerns as other countries, including Japan and Germany, joined England and Scotland in banning flights from six countries in the region, while Israel said it had identified its first case with the variant.
Hopkins told BBC Radio 4’s Today programme: “What we’re seeing in South Africa is that they were at a very, very low point, with a very low amount of cases being detected a day, and in a shorter period than two weeks they have more than doubled their epidemiology picture.
“They are saying that their transmission rates, the R value that they have in Gauteng around where this was first found, is now 2, which is really quite high and we’ve not seen levels of transmission like that since right back at the beginning of the pandemic, because of all of the mitigations and steps we’ve taken. So that would cause a major problem if you had that high transmission with this type of virus in a population where it may evade the immune responses that are already there.”
She stressed that no cases had been identified in the UK yet and that one of the 30 mutations of the B.1.1.529 variant was very similar to one of the alpha mutations, meaning it could be detected easily with a large amount of existing PCR tests, but had not shown up yet.
Hopkins said some of the mutations were likely to change the immune response, as had already been seen in South Africa, whose population, although not highly vaccinated, has high immunity from previous rounds of infection, but that only time would tell the extent. “We would like more details in laboratory studies and epidemiological studies. I know the South Africans have already started to give us that information, but it will take weeks rather than days to find the full information,” she said.
The transport secretary, Grant Shapps, said the government was taking a “safety-first approach” to the new variant but it did not necessitate reintroducing enforcement of the use of face masks in public transport and shops.
He told Sky News: “We want the economy to be able to flourish, we want people to be able to go about their business, see their friends and family. So we’re trying to operate as permissive an atmosphere as possible but, of course, we’re keeping a very close eye on this all the time. So far, in all the numbers, we haven’t seen any reason to do anything else.”
South Africa, Namibia, Lesotho, Botswana, Eswatini and Zimbabwe were placed on England’s travel red list on Thursday and flights are banned from Friday.
South Africa’s foreign ministry said the decision to ban flights from South Africa “seems to have been rushed”
The World Health Organization (WHO) appeared to concur. “At this point, implementing travel measures is being cautioned against,” the WHO spokesperson Christian Lindmeier told a UN briefing in Geneva on Friday. “The WHO recommends that countries continue to apply a risk-based and scientific approach when implementing travel measures.”
Israel, which like England and Scotland announced a ban on Thursday, said it had identified the new variant in a traveller returning from Malawi. The prime minister, Naftali Bennett, said on Friday: “We are close to an emergency situation … we must act strongly and quickly.”
France suspended all flights from southern Africa for 48 hours.
Ursula von der Leyen, the president of the European Commission, tweeted on Friday that it would also propose stopping travel from the southern Africa region.