The British drug manufacturer says that the vaccine shows ‘limited efficacy against mild diseases’ through the South African variant of the coronavirus.
The spokesperson for the British drug manufacturer said that the COVID-19 vaccine developed by AstraZeneca and the University of Oxford offers only limited protection against mild diseases.
The statement came on Saturday after the Financial Times reported that the vaccine could not prevent a mild and moderate illness caused by the variant first identified in South Africa.
The newspaper quoted earlier data from a trial conducted by the South African University of the Witwatersrand and the University of Oxford, the findings of which are to be published on Monday.
The FT noted that none of the more than 2,000 mainly healthy and young participants in the trial were admitted to the hospital or died. The findings have yet to be peer-reviewed.
A AstraZeneca spokesperson said in the FT report: ‘In this small phase I / II study, early data showed limited efficacy against mild diseases, mainly due to the South African variant B.1.351.
“However, we could not properly determine its effect on serious illness and hospitalization, as the subjects were predominantly young healthy adults.”
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 spokesperson also said that AstraZeneca has started adapting the vaccine against the South African variant and ‘will progress rapidly through clinical development so that it is ready for autumn delivery if needed’.
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.
Among the coronavirus variants currently the most important for public health scientists and experts are the so-called “South African”, “British” and “Brazilian” variants, which appear to be spreading faster than others.
Other vaccine developers, including Johnson & Johnson and Novax, have also said that their vaccines show reduced efficacy in clinical trials conducted in South Africa.
The Johnson & Johnson vaccine was 57 percent effective in South Africa, compared to 72 percent in the United States and 66 percent in Latin America. Meanwhile, Novax said the vaccine was 89.3 percent effective in a trial conducted in the United Kingdom, but showed only 50 percent effectiveness in a trial conducted in South Africa.
Moderna also reported a reduced immune response of his vaccine against the South African variant, and said he would test a new booster shot on the variant.
Scientists say the mutations highlight the need to accelerate vaccination efforts before new and even more dangerous variants emerge.