South Africa suspends AstraZeneca vaccinations due to variant data

JOHANNESBURG (Reuters) – South Africa will suspend use of AstraZeneca’s COVID-19 vaccine in its vaccination schedule, after data showed it offered minimal protection against mild to moderate infections caused by the country’s dominant variant of the coronavirus.

Health Minister Zweli Mkhize said on Sunday the government would await advice from scientists on how best to proceed, after a trial showed the AstraZeneca vaccine did not significantly reduce the risk of COVID-19 mild or moderate of the 501Y.V2 variant which caused a second wave of infections that began late last year.

Before the widespread spread of the most contagious variant, the vaccine showed about 75% effectiveness, according to the researchers.

In a subsequent analysis based primarily on infections with the new variant, there was only a 22% lower risk of developing mild to moderate COVID-19 compared to those given a placebo. Although the researchers said the figure was not statistically significant, due to the design of the trial, it is well below the benchmark of at least 50% that regulators have set for vaccines to be. considered effective against the virus.

The study did not assess whether the vaccine helped prevent severe COVID-19, as it primarily affected relatively young adults not considered to be at high risk for serious illness.

AstraZeneca said on Saturday that she believed her vaccine could protect against serious illness and had already started adapting it against the 501Y.V2 variant.

Still, Professor Shabir Madhi, principal investigator on the AstraZeneca trial in South Africa, said the vaccine data was a reality check and it was time to “recalibrate our expectations regarding COVID-19 vaccines. “.

South Africa hopes to vaccinate 40 million people, or two-thirds of the population, to achieve some level of herd immunity, but has yet to administer a single vaccine.

He had hoped to deploy the AstraZeneca vaccine to healthcare workers shortly after receiving 1 million doses produced by the Serum Institute of India (SII) on Monday.

Instead, it will offer health workers vaccines developed by Johnson & Johnson and Pfizer / BioNTech in the coming weeks.

“What does this mean for our immunization program which we expect will start in February? The answer is that it will continue, ”Mkhize said during an online press briefing. “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 vaccinations was needed, given the uncertainty over the effectiveness of current vaccines against the 501Y.V2 variant.

First, a vaccine needs to be used in a targeted group to assess hospitalization rates, and then if it is found to be effective in reducing hospitalizations, it could be in a large-scale deployment, he said. declared.

If it was not effective in reducing hospitalizations, people who received it should be offered another effective vaccine, either a booster based on the variant or another vaccine, Abdool Karim added.

South Africa is likely to experience a third wave of infections when winter begins in about four months, Madhi said.

He added that it would be “somewhat reckless” to reject the million doses of AstraZeneca the country had received when there was still a chance that it could protect itself from severe COVID-19.

Anban Pillay, deputy director general of the Ministry of Health, said the expiration date for AstraZeneca doses was April, but the government was speaking to the SII to request an extension or a trade.

Madhi said South Africa may wish to reframe its target group for vaccination. “It really needs to be focused on preventing serious illness and death from what will likely be a resurgence in the near future.”