By Derek Francis and Andy Bruce
(Reuters) – British drugmaker AstraZeneca said on Saturday that the vaccine developed with the University of Oxford appears to offer only limited protection against mild illnesses caused by the South African variant of COVID-19, based on early data from a trial.
The study by the South African University of the Witwatersrand and the University of Oxford showed that the vaccine significantly reduced its effectiveness against the South African variant, according to a Financial Times report published earlier in the day.
Among the coronavirus variants currently most important to public health scientists and 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 showed limited efficacy against mild diseases, mainly due to the South African variant B.1.351,” a spokesman for AstraZeneca said in response to the FT report.
According to the newspaper, none of the more than 2,000 participants in the trial were admitted to hospital or killed.
“However, we could not properly determine its effect on serious illness and hospitalization, as the subjects were mainly young healthy adults,” the AstraZeneca spokesperson said.
The company said it believes the vaccine can protect against serious diseases as the neutralizing antibody activity is similar to that of other COVID-19 vaccines that have shown protection against serious diseases.
The FT said the trial, which involved 2026 people, half of whom formed the placebo group, had not been evaluated.
While thousands of individual changes have occurred as the virus changes into new variants, only a small minority care about whether the virus will change in a significant way, according to the British Medical Journal.
“The University of Oxford and AstraZeneca have started adapting the vaccine against this variant and will progress rapidly through clinical development so that it is ready for autumn delivery should the need arise,” the AstraZeneca spokesperson said.
On Friday, Oxford said their vaccine had similar efficacy against the British coronavirus variant as with the variants previously in circulation.
(Edited by Derek Francis in Bengaluru; edited by Timothy Heritage, Daniel Wallis and David Gregorio)