South Africa has scrapped its plans to vaccinate a portion of its population with the COVID-19 vaccine from Oxford University and AstraZeneca (LON:AZN) after a small study showed it was ineffective against a variant widely circulating there.
Researchers at Oxford University and the University of the Witwatersrand in South Africa found the AstraZeneca vaccine to offer little to no protection against mild-to-moderate disease. The research has not been peer-reviewed.
Out of a pool of 748 study participants given the AstraZeneca vaccine, 19 contracted mild or moderate COVID-19 infections compared to 20 people in the placebo group of 714. There were no cases of severe illness in the trial, which did not include elderly participants. The median age in the trial was 31.
Before the recent trial data were announced, the country had amassed 1 million doses of the AstraZeneca vaccine.
The B.1.351 South Africa variant, which has 10 mutations on its spike protein, also appears to pose a higher risk of reinfection than earlier SARS-CoV-2 lineages. That variant has inspired Moderna (NSDQ:MRNA) and Novavax (NSDQ:NVAX) to test new constructs to battle it.
Johnson & Johnson recently published data suggesting that its vaccine effectively prevents severe illness in various locations, including South Africa.