Health Minister Zweli Mkhize has announced that the rollout of the first COVID-19 vaccines to arrive in South Africa has been temporarily halted.
This decision was taken after the completion of AstraZeneca vaccine trials conducted by the University of the Witwatersrand as part of a study by Oxford University.
Researchers discovered that the AstraZeneca vaccines which arrived in South Africa last week are minimally effective against the South African variant of the coronavirus.
As this variant is the dominant strain in South Africa, the rollout of these COVID-19 vaccines have been halted temporarily until scientists can resolve on a way forward, Mkhize said in a media briefing on 7 February.
The vaccination of South Africans with other COVID-19 vaccines, namely those manufactured by Johnson & Johnson and Pfizer, will proceed as these vaccines land in South Africa.
“The AstraZeneca vaccine will remain with us up until the scientists give us clear indications as to what we need to do,” he said.
Wits University professor Shabir Madhi said the results of the AstraZeneca trial were disappointing, as the AstraZeneca vaccine could not produce its purported level of efficacy against the South African variant of the coronavirus.
He added that if the coronavirus did not mutate, the results would have been far better.
However, he also noted that the one-dose vaccine created by Johnson & Johnson is expected to be more effective against the dominant strain in South Africa.
Less effective against 501Y.V2
This follows previous reports that the AstraZeneca COVID-19 vaccine seemed to be far less effective against the 501Y.V2 or “South African” variant of the coronavirus.
The vaccine has previously been shown to have an efficacy of between 63% and 90% on two doses, but to date, it was not certain how efficient it would be against new COVID-19 variants.
AstraZeneca confirmed the report, saying its vaccine appears to only provide limited protection against mild disease caused by the “South African variant” based on early data from a study conducted by the University of the Witwatersrand and Oxford University.
It said they are currently adapting the vaccine to protect against the 501Y.V2 variant and that the clinical development is expected to advance rapidly.
“Efforts are underway to develop a new generation of vaccines that will allow protection to be redirected to emerging variants as booster jabs if it turns out that it is necessary to do so,” said Professor of Vaccinology at the University of Oxford Sarah Gilbert.
“We are working with AstraZeneca to optimise the pipeline required for a strain change should one become necessary.”
“This is the same issue that is faced by all of the vaccine developers, and we will continue to monitor the emergence of new variants that arise in readiness for a future strain change,” she said.”