South Africa halts AstraZeneca vaccine over new variant

South Africa has put its roll-out of the Oxford-AstraZeneca vaccine on hold after a study showed "disappointing" results against its new Covid variant.

Scientists say the variant accounts for 90% of new Covid cases in South Africa.

The study, involving around 2,000 people, found the vaccine offered "minimal protection" against mild and moderate cases.

But experts say there is still hope that it will be effective in preventing severe infections.

South Africa has recorded more than 1.4 million cases of coronavirus and 46,000 deaths since the pandemic began, according to data collated by Johns Hopkins University. The country has received 1m doses of the Oxford-AstraZeneca jab and was due to start vaccinating people next week.

Speaking at an online news conference on Sunday, South African Health Minister Zweli Mkhize said his government would wait for further advice on how best to proceed with the AstraZeneca vaccine in light of the findings.

In the meantime, he said, the government will offer vaccines produced by Johnson & Johnson and Pfizer in the coming weeks.

The trial was carried out by the University of the Witwatersrand but has not yet been peer reviewed.

Prof Shabir Madhi, who led the study, told reporters it showed that "unfortunately, the AstraZeneca vaccine does not work against mild and moderate illness".

Prof Madhi said the study had not been able to investigate the vaccine's efficacy in preventing more serious infections, as participants had an average age of 31 and so did not represent the demographic most at risk of severe symptoms from the virus.

Prof Sarah Gilbert, Oxford's lead vaccine developer, said the vaccine should still protect against severe disease.

"What we're seeing from other vaccine developers is that they have a reduction in efficacy against some of the variant viruses and what that is looking like is that we may not be reducing the total number of cases, but there's still protection in that case against deaths, hospitalisations and severe disease," she told the Andrew Marr Show on Sunday.

She said developers were likely to have a modified version of the injection against the South Africa variant, also known as 501.V2 or B.1.351, later this year.

Prof Tulio de Oliviera, an epidemiologist at the Nelson R Mandela School of Medicine, said he hoped the vaccine would still have a role to play in South Africa's vaccination programme.

"Our hope is that despite the very low efficacy on a small phase two trial in South Africa on the mild infections, that we would still see some efficacy on severe infections," he told the BBC.

UK Vaccines Minister Nadhim Zahawi said the vaccine appeared to work well against dominant variants in the UK., adding: "We need to be aware that even where a vaccine has reduced efficacy in preventing infection there may still be good efficacy against severe disease, hospitalisation, and death."

Early results from Moderna suggest its vaccine is still effective against the South Africa variant, while AstraZeneca has said its vaccine provides good protection against the UK variant first identified in the UK.

Early results suggest the Pfizer-BioNTech vaccine protects against the new variants.

The news from the South Africa is clearly alarming.

But we should be careful about not rushing to judgement just yet.

The numbers involved in the trial were small - so it means there can only be limited confidence in the findings at the moment - and there is a hope that the vaccine will still stop people becoming severely ill.

What is more, the South African variant is nowhere near the dominant type in the UK.

Nearly 150 cases have been identified here - although that is bound to be an underestimate as they have been found via random checks on positive tests that are carried out on between 5% and 10% of cases.

What is more, there are mutations in some of the virus circulating in the UK that mirror the concerning change in the South Africa variant.

That is why the government has introduced testing in the areas where these variance have been found.

It once again illustrates how challenging the pandemic is. It is not going to end with a Big Bang.

But the progress the vaccines still offer is the route out.

There is no evidence that the South African variant causes more serious illness for the vast majority of people who become infected.

As with the original version, the risk is highest for people who are elderly or have significant underlying health conditions.

The South African variant carries a mutation, called N501Y, that appears to make it more contagious or easy to spread.

At least 20 other countries including Austria, Norway and Japan, have also found cases.