Will the omicron variant bypass vaccines? South African experts say it will take ‘weeks’ to find out

South African experts say it will take “weeks and weeks” to see if the most mutated Covid-19 variant ever detected has the ability to bypass Western vaccines.

Professor Salim Abdool Karim, former chairman of South Africa's Ministerial Advisory Committee on Covid-19, told The Telegraph it would take weeks to see if Pfizer and Johnson & Johnson vaccines will defend against the new B.1.1.529 variant.

The highly contagious variant, has double the number of mutations of the Delta variant and is currently driving an explosion of cases in the region around Johannesburg, South Africa’s commercial capital.

Late on Thursday evening, Britain put six southern African countries – South Africa, Botswana, Lesotho, Eswatini, Zimbabwe and Namibia – on a revamped red list and said it would stop flights on Friday until a system was put in place to quarantine passengers.

Israel quickly followed suit suspending all travel to and from South Africa. On Friday the European Union said it would propose banning travel from southern Africa.

The new variant, named omicron on Friday, was first discovered in Botswana, but cases have been detected in Hong Kong. Scientists say it is almost entirely behind an explosion of cases in Southern Africa's Gauteng Province in the last week.

“We have only known of this variant for a few days and know very little about how it behaves. However, we can extrapolate based on the mutations that we have seen… this particular variant has features and mutations which are present in all four of the variants of concern,” Professor Karim said.

Speaking anonymously to The Telegraph, another senior member of South Africa's top Covid-19 committee said that “weeks and weeks” of tests would need to be run before anyone could say clearly what threat the new B.1.1.529 variant posed to vaccine defences.

The new variant probably evolved during chronic infection of an immuno-compromised person, possibly in an untreated HIV/Aids patient, said Francois Balloux, director of the University College London Genetics Institute.

South Africa has the world's largest number of people living with HIV/AidsS – about 7.7m or 20.4 per cent of the population.

This has made it far more difficult for the country to fight the pandemic, as the virus can linger for longer in people whose immune systems are compromised, widening the window for mutations to happen.

The country is highly urbanised, and tens of millions of black South Africans live in crowded townships, a legacy of the apartheid era.

Experts say this has increased the rate of transmission in the country compared to other African nations, which are still predominantly rural.

Protect yourself and your family by learning more about Global Health Security