(Reuters) – British drug company AstraZeneca AZN.L said on Saturday that the vaccine developed with the University of Oxford appears to offer only limited protection against mild disease caused by the South African variant of COVID-19, based on early data from a trial.
The study from the South Africa University of the Witwatersrand and Oxford University found that the vaccine had significantly reduced its effectiveness against the South African variant, according to a report from the Financial Times published earlier today.
Among coronavirus variants currently of greatest concern to scientists and public health experts are the so-called British, South African and Brazilian variants, which appear to be spreading faster than others.
“In this small phase I / II trial, early data have shown limited efficacy against mild disease, mainly due to South African variant B.1.351,” an AstraZeneca spokesperson said in response to the FT report.
The newspaper said none of the more than 2,000 subjects had been hospitalized or died.
“However, we have not been able to properly establish its effect on severe illness and hospitalization as the subjects were predominantly young healthy adults,” said AstraZeneca’s spokesperson.
The company said it believed its vaccine could protect against serious illness as the neutralizing antibody activity was similar to other COVID-19 vaccines that have shown protection against serious illness.
The trial, which involved 2,026 people, half of whom made up the placebo group, has not been peer-reviewed, the FT said.
While thousands of individual changes have occurred as the virus mutates into new variants, only a small minority is likely to be important or the virus to change in any noticeable way, according to the British Medical Journal.
“Oxford University and AstraZeneca have begun to modify the vaccine against this variant and will make rapid progress in clinical development so that it is ready for fall delivery should the need arise,” said AstraZeneca spokesperson.
On Friday, Oxford said their vaccine has similar efficacy against the British coronavirus variant as against the previously circulating variants.
Reporting by Derek Francis in Bengaluru; Edited by Timothy Heritage, Daniel Wallis and David Gregorio