JOHANNESBURG (Reuters) – South Africa will suspend the use of AstraZeneca’s COVID-19 vaccine in its vaccination program after data showed that it gave minimal protection against mild to moderate infection caused by the country’s dominant coronavirus variant.
Health Minister Zweli Mkhize said on Sunday that the government would await the scientists’ advice on the best way to proceed, after a trial showed that the AstraZeneca vaccine did not significantly reduce the risk of mild or moderate COVID-19 from the 501Y variant. .V2 that caused a second wave of infections starting at the end of last year.
Before the widespread circulation of the most contagious variant, the vaccine was around 75% effective, the researchers said.
In a subsequent analysis based mainly on infections by the new variant, there was only a 22% lower risk of developing mild to moderate COVID-19 compared to those who received a placebo. Although the researchers said the number was not statistically significant, due to the design of the trial, it is well below the benchmark of at least 50% of regulators have established for vaccines to be considered effective against the virus.
The study did not assess whether the vaccine helped prevent severe COVID-19 because it involved mainly relatively young adults not considered to be at high risk for serious illnesses.
AstraZeneca said on Saturday that it believes its vaccine can protect against serious illnesses and has already started adapting it against the 501Y.V2 variant.
Still, Professor Shabir Madhi, principal investigator for the AstraZeneca study in South Africa, said the vaccine data was a reality check and it was time to “recalibrate our expectations for the COVID-19 vaccines”.
South Africa hopes to vaccinate 40 million people, or two-thirds of the population, to achieve some level of collective immunity, but has not yet administered a single injection.
She hoped to launch the AstraZeneca vaccine for healthcare professionals shortly after receiving 1 million doses produced by the Serum Institute of India (SII) on Monday.
Instead, it will offer vaccines to healthcare professionals developed by Johnson & Johnson and Pfizer / BioNTech in the coming weeks.
“What does this mean for our vaccination program, which we said will start in February? The answer is that it will continue, ”said Mkhize at an online press conference. “Starting next week for the next four weeks, we expect J&J vaccines, there will be Pfizer vaccines.”
NEW APPROACH
Professor Salim Abdool Karim, an epidemiologist who advises the government, said there needs to be a new approach to immunizations, given the uncertainty about the effectiveness of current vaccines against the 501Y.V2 variant.
First, a vaccine must be used in a target group to assess hospitalization rates, and then, if it is effective in reducing hospitalizations, it can be included in a large-scale implementation, he said.
If it was not effective in reducing hospitalizations, individuals who received it should receive another effective vaccine, a booster based on the variant or another vaccine, added Abdool Karim.
South Africa is likely to experience a third wave of infections when winter begins, around four months, Madhi said.
He added that it would be “somewhat unwise” to discard the 1 million doses of AstraZeneca that the country received when there was still a serious chance of protection against COVID-19.
Anban Pillay, deputy director general of the ministry of health, said that the AstraZeneca dose expired in April, but the government was talking to the SII to request an extension or exchange.
Madhi said South Africa may want to reshape its target group for vaccination. “It really needs to be focused on 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