British drugmaker AstraZeneca said on Saturday that its vaccine developed in association with the University of Oxford appeared to provide only limited protection against mild diseases caused by the South African version of COVID-19, based on early trial results.
According to a Financial Times article published earlier in the day, the research from South Africa’s University of the Witwatersrand and Oxford University showed that the vaccine had substantially decreased efficacy against the South African version.
The so-called British, South African and Brazilian strains, which tend to spread more rapidly than others, are among the coronavirus variants currently most concerning to scientists and public health experts.
“In this small phase I/II trial, early data has shown limited efficacy against mild disease primarily due to the B.1.351 South African variant,” an AstraZeneca spokesman said in response to the FT report.
None of the more than 2,000 study participants was hospitalised or died, the newspaper reported.
“However, we have not been able to properly ascertain its effect against severe disease and hospitalisation gave that subjects were predominantly young healthy adults,” said the AstraZeneca spokesperson.
Limited Protection Against Mild Diseases
The company stated that it assumed that its vaccine could protect against severe diseases, provided that the efficacy of the neutralizing antibody was similar to that of other COVID-19 vaccines that have been shown to protect against serious diseases.
The trial, involving 2,026 individuals of whom half formed the placebo group, was not peer-reviewed, the FT said.
Although thousands of individual changes have occurred as the virus mutates into new forms, only a tiny minority are likely to be important or change the virus in an appreciable way according to the British Medical Journal.
“Oxford University and AstraZeneca have started adapting the vaccine against this variant and will advance rapidly through clinical development so that it is ready for Autumn delivery should it be needed,” said the spokesman for AstraZeneca.
Oxford said on Friday that their vaccine has equal effectiveness against the British strain of coronavirus as it does against the strains previously circulating.
