Covid: Good news for success of vaccine against new UK strain - but what about South Africa?

Tom Clarke

Former Science Editor

On Friday we had something of a rare event: a scrap of good news. A very preliminary study suggests that the more infectious strain of Covid circulating in the UK is just as vulnerable to the vaccines we’ve designed as the “original” Covid strains.

But the research is still less certain about the South African strain of the virus.

As we report from Soweto, it now accounts for more than 80% of cases of Covid in South Africa and has now almost certainly spread to other countries on the continent and probably elsewhere in the world too. 

The UK strain of the virus has a potentially important mutation on its spike protein - right where the virus binds to receptors on our cells, helping it to invade.

A man is tested at a mobile clinic at a taxi rank at Johannesburg's main railway station. Credit: AP

But the South Africa strain has an additional one. This second mutation, called E484K, may be even more critical than the one on the UK variant which it also shares. 

It’s why researchers in the UK are anxious to find out how the South Africa variant responds to antibodies produced by people who have already had Covid or form those vaccinated -particularly with the Oxford/AstraZeneca jab which is currently being deployed at scale in the UK.

The answers, however, will likely come from South Africa.

This isn’t only where the worrying Covid variant is most common, it’s also where more than 10,000 people have been given the Oxford/AstraZeneca vaccine. If we’re going to get definitive answer they’ll be the ones we get it from.

The Oxford University/AstraZeneca Covid-19 vaccine. Credit: PA

The first hints will come from South Africa’s virology laboratories - some of the best in the world due to their decades-long struggle with HIV.

Scientists there successfully isolated the new strain a few weeks ago and have been testing it against antibodies from people who have been vaccinated with the Oxford/AstraZeneca vaccine or infected with older variants of Covid.

They will also be able to see what might be able to give the new strain its edge.

Early experiments are suggesting the UK variant may be able to replicate faster in lung cells than older strains. Could the explain the South African variants advantages too?

I understand the first results of those experiments could be available as early as next week.

But the answers we really need will come from the ongoing vaccine trial based in Africa’s largest hospital in Soweto outside Johannesburg.

Volunteers wait to be checked at a vaccine trial facility set at Soweto's Chris Sani Baragwanath Hospital outside Johannesburg. Credit: AP

Although the data showing the vaccine is effective has already been used to get the jab approved here in the UK and elsewhere, the study continues.

Volunteers recruited in the trial are still being followed up by researchers there.

What they really want to know is: Are people who were vaccinated six months ago - before the new variant was on the scene - now becoming infected?

And if they are, are they protected from getting seriously ill? The researchers in Soweto are taking Covid samples from all the participants coming in for their follow-up appointments.

Soon they will know if the vaccine protects them against the new variant. And if it doesn’t, how reduced the potency of the vaccine will be.