The South African government decided to suspend the application of the vaccine developed by Oxford University and AstraZeneca after a study showed very limited efficacy against the variant of the coronavirus (501Y.V2 or B.1.351) discovered in the country.
South African Health Minister Zweli Mkhize and several of the experts leading the response against COVID-19 announced late Sunday the move in a virtual press appearance.
“It is temporary until we study the next step,” said Mkhize, who will now work against the clock with his team to rethink the vaccination strategy in the African country hardest hit by the pandemic.
The decision not to apply the AstraZeneca vaccine (the only one that had so far arrived in the country) was taken after the release of preliminary data from a study developed by the University of Oxford and the University of Witwatersrand (Johannesburg).
According to the study, which will be published on Monday but whose findings were reported on Sunday by the British newspaper Financial Times, the solution was only about 22% effective against mild and moderate cases of the 501Y.V2 (or B.1.351) variant.
This was discovered in the country last December and has since become dominant. It is 50% more contagious, according to data collected so far, but has not manifested itself more severely for patients.
Whether or not, despite its low overall efficacy, the Oxford vaccine is effective in preventing severe cases of covid-19; that is, deaths and hospitalizations, is unknown, since the people involved in the study were from low-risk groups: 2,000 people who were mostly young adults in good health.
“This is very disappointing news. What I have to emphasize is that two-thirds (of the infections) in the study were from mild infection and one-third from moderate disease. What the data doesn’t tell us is whether it protects against severe disease,” stressed vaccination expert Shabir Madhi, a professor at the University of the Witwatersrand.
The news forces the southern country to rethink its vaccination strategy, after the optimism aroused only a week ago by the receipt of the first batch of vaccines.
Specifically, one million doses from AstraZeneca arrived from the Serum Institute of India and South Africa expected to start administering them to health workers in the next few days.
The priority now for Pretoria will be to make available as soon as possible the first doses of vaccines from Johnson & Johnson and Pfizer/BioNTech, which have shown sufficient efficacy against the dominant coronavirus variant in South Africa.
South Africa is also already in discussions with other vaccine producers.
Despite this setback, South Africa maintains its plan to begin immunizing its healthcare workers this month.
To date, South Africa has counted 1,476,135 cases of covid-19. It is by far the country in Africa most affected by the pandemic. Of these cases, 1,360,204 have been discharged and 46,290 have died.
The news also raises questions for the vaccination campaign in other African countries, especially those bordering South Africa, as they would face the same problem with the Oxford vaccine if the South African variant were to spread to other parts of the continent.
Due to its low cost, better procurement options through the Indian Serum Institute and easier storage conditions, AstraZeneca is the source of a large part of the doses that the continent has secured, for the time being, through the COVAX platform or the African Union’s joint purchasing mechanism.