The controversy surrounding South Africa’s haphazard Covid-19 vaccine procurement and rollout continues. After the release of local trial data showing low efficacy, the country has halted the rollout of the long awaited AstraZeneca vaccine. The trial only assessed the vaccine’s effect in mild to moderate cases of the disease and the test subjects were relatively healthy with a median age of 31 years. In light of the size and restricted scope of the study, the World Health Organisation Director-General, Dr Tedros Adhanom Ghebreyesus, said that it is vital that the vaccine is assessed in the context of serious illness. In the meantime Covax will continue preparations for distribution of the vaccine, procured through the Serum Institute of India. South Africa’s Ministerial Advisory Committee Co-chair, Professor Salim Abdool Karim said a staggered rollout is being considered. ‘We don’t want to end up with a situation where we vaccinate a million people or two million people with a vaccine that may or may not be effective in preventing hospitalisation or severe disease,’ said the professor. – Melani Nathan
Astra Covid shot still useful in variant-hit areas, WHO Says
By Corinne Gretler and Mike Cohen
(Bloomberg) – AstraZeneca’s Covid-19 vaccine is worth using in areas hit by mutated strains of the virus, World Health Organization officials and partners said, countering concerns about reduced effectiveness that arose in a recent test.
There’s evidence the vaccine AstraZeneca developed with the University of Oxford could provide meaningful protection against severe disease caused by the highly infectious variant that emerged in South Africa, called B.1.351, according to Kate O’Brien, who heads the WHO’s vaccination division. The global health agency is preparing to decide on an emergency-use listing for Astra-Oxford shots made in India and South Korea.
“There was a very positive view about proceeding with the use of the vaccine, including in settings where variants are circulating,” O’Brien said at a briefing.
South Africa said it would pause the shot’s rollout after a trial showed it had just 22% efficacy against the new variant that was identified in the country late last year. The country is instead accelerating its supply of vaccines from Johnson & Johnson, which has yet to gain authorization, and Pfizer.
Data from a South African arm of a trial of the Astra vaccine found it had limited efficacy against mild and moderate illness, lead researcher Shabir Madhi said. There was no conclusive data showing whether it protects against severe illness, mainly because of relatively young age among the 2,000 trial participants, he said.
The decision to halt use of AstraZeneca’s shots could slow South Africa’s vaccination rollout, said Salim Abdool Karim, co-chair of the nation’s Covid-19 ministerial advisory committee. The country may consider issuing the shot in stages until a clearer picture of its efficacy emerges, he said in the briefing.
It’s not surprising that the vaccine has shown more limited efficacy against mild disease in cases involving the South African variant, according to Andrew Pollard, chief investigator on the Oxford vaccine trials. What’s more important is that the shot still appears to prevent more serious problems, he said in a BBC radio interview.
“We are going to see new variants arise and they will spread in the population like most of the viruses that cause colds every winter, but as long as we have enough immunity to prevent the severe disease, hospitalization and death, then we’re going to be fine,” he said.
It’s too early to dismiss the AstraZeneca vaccine, which is a very important part of the global response to the current pandemic, according to Richard Hatchett, chief executive officer of the Coalition for Epidemic Preparedness Innovations, an organization that’s worked to accelerate development of Covid-19 vaccines.
“We probably need to find better vaccines against the variants that are emerging,” he said at the briefing, adding that when supplies increase, it may make sense to deploy vaccines to certain geographies.
“We don’t have that luxury yet,” Hatchett said.