JOHANNESBURG (Reuters) – South Africa will discontinue use of AstraZeneca’s COVID-19 inclusion in its vaccination program after data showed it provided minimal protection against mild to moderate infection caused by the country’s dominant coronavirus strain.
Health Minister Zweli Mkhize said on Sunday that the government would wait for advice from scientists on how best to proceed, after a trial showed that the AstraZeneca vaccine reduced the 501Y’s risk of mild or moderate COVID-19.V2- variant that started a second wave of infections late last year.
Before the more contagious variant was widely spread, the vaccine showed about 75% efficacy, researchers said.
In a later analysis based mainly on infections from the new variant, there was only a 22% less chance of developing mild to moderate COVID-19 compared to those who received a placebo. Although researchers said the figure was not statistically significant, because of the trial design, it is well below the benchmark of at least 50% of regulators who considered vaccines to be effective against the virus.
The study did not evaluate whether the vaccine helped prevent severe COVID-19, as it mainly affected relatively young adults who were not considered to be at high risk of serious disease.
AstraZeneca said on Saturday it believed its vaccine could protect against serious illness and had already begun to modify it against the 501Y.V2 variant.
Still, Professor Shabir Madhi, lead investigator of the AstraZeneca study in South Africa, said the vaccine data was a reality check and it was time to “recalibrate our expectations of COVID-19 vaccines.”
South Africa hopes to vaccinate 40 million people, or two-thirds of the population, to achieve some immunity to the herd, but has not yet given a single injection.
It had hoped to receive the AstraZeneca vaccine shortly after receiving 1 million doses produced by the Serum Institute of India (SII) shortly after receiving the AstraZeneca vaccine for health professionals.
Instead, it will be offering vaccines to health professionals developed by Johnson & Johnson and Pfizer / BioNTech in the coming weeks.
“What does that mean for our vaccination program that we said will start in February? The answer is that it will continue, ”Mkhize told an online newsletter. “Starting next week, for the next four weeks, we expect there will be J&J vaccines, there will be Pfizer vaccines.”
NEW APPROACH
Professor Salim Abdool Karim, an epidemiologist who advises the government, said a new approach to immunizations was needed, given the uncertainty about how effective current vaccines would be against the 501Y.V2 variant.
First, a vaccine must be used in a target population to assess hospital admission rates, and if it proves to be effective in reducing hospital admissions, it could play a role in a large-scale rollout, he said.
If it was not effective in reducing hospital admissions, individuals who received it should receive a different effective vaccine, either a booster based on the variant or a different vaccine, Abdool Karim added.
It’s likely South Africa will get a third wave of infections when winter sets in about four months, Madhi said.
He added that it would be “somewhat reckless” to throw away the 1 million AstraZeneca doses the country had received while there was still a chance they could protect against severe COVID-19.
Anban Pillay, deputy director general of the health ministry, said the AstraZeneca doses were due to expire in April, but the government spoke with the SII to seek an extension or exchange.
Madhi said South Africa might want to reformulate its target population for vaccination. “It really needs to be aimed at preventing serious illness and death from what is likely to be a resurgence soon.”
Reporting by Alexander Winning and Olivia Kumwenda-Mtambo; Editing by Alexander Smith and Bill Berkrot