Lower effectiveness: South Africa halts AstraZeneca vaccine rollout

Lower effectiveness: South Africa halts AstraZeneca vaccine rollout
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Health officials in South Africa have decided to pause the rollout of the AstraZeneca Covid-19 vaccine due to its lower effectiveness against the variant.

A study revealed that the AstraZeneca Covid-19 vaccine offers less protection from the coronavirus variant first identified in South Africa, prompting health officials to halt the scheduled distribution of the vaccine.


South Africa Minister of Health Dr. Zweli Mkhize announced in a briefing that the AstraZeneca vaccine rollout will be halted temporarily while scientists examine how to effectively deploy it.

However, Dr. Mkhize said the deployment of the Pfizer-BioNTech and Johnson & Johnson vaccines will push through.

African variant trial

Early results from the study indicated that two doses of the AstraZeneca vaccine offered only "minimal protection" against mild and moderate Covid-19 from the South Africa variant.


The trial involved around 2,000 volunteers with an average age of 31 years old, with about half given the vaccine while the other half received a placebo.

According to the researchers, they found that viral neutralization against the B.1.351 variant was "substantially reduced" in comparison with the original Covid-19 strain. They have not assessed the vaccine's efficacy against severe Covid-19, hospitalization and death.

The researchers who conducted the study were from South Africa's University of Witwatersrand and others, as well as from the University of Oxford. The results have been submitted for peer-review and a preprint will be released soon, according to Oxford.


In response to the announcement, an AstraZeneca spokesperson said the firm is "working closely with the South African Ministry of Health on how best to support the evaluation against severe disease of the B.1.351 variant, and start to bring this vaccine to the South African people should it prove to be successful."

AstraZeneca believes that its vaccine will still be effective against severe disease from the new B.1.351 variant, particularly when the doses are given at interval of eight to 12 weeks.

The World Health Organization's (WHO) technical lead for Covid-19 Maria Van Kerkhove said that the WHO's independent vaccine panel will hold a meeting to discuss the AstraZeneca vaccine and how the new study impacts vaccines going forward.

Van Kerkhove mentioned that "some preliminary studies suggesting reduced efficacy. But again, those studies aren't fully published yet" and added that it's crucial to have more than one safe and effective vaccine: "We cannot rely on only one product."

Threat to antibody treatments

Last month, White House health advisor Dr. Anthony Fauci said the Covid variant detected in South Africa poses a threat to antibody treatments.

After discussions with health experts in South Africa, Dr. Fauci said that preliminary data suggests there is “more of a threat” the strain would break away from some of the protections antibody treatments produce.

“It could be having some impact on protection for the monoclonal antibodies and perhaps even for the vaccine. We don’t know that,” Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a Q&A session at Schmidt Futures’ Forum on Preparedness.

According to him, researchers at the National Institutes of Health and across the country are examining the possible impact of the strain found in South Africa.

“People ask me, ‘Are you worried about it?’ These are not the kind of things I worry about, but it’s the kind of thing that I take very seriously,” Fauci said.