Astra Vaccine Shows Less Effect Against South Africa Variant

(Bloomberg) --

AstraZeneca Plc’s Covid-19 vaccine has shown limited efficacy against mild disease caused by the variant first identified in South Africa, according to early data in a small phase trial.

Efficacy against severe Covid-19 cases, hospitalization and deaths hasn’t yet been determined, “given that subjects were predominantly young healthy adults,” a spokesperson for AstraZeneca said in a statement.

None of the participants in the study died or was hospitalized, according to the Financial Times, which first reported on the findings. The study, with a relatively small sample size of more than 2,000 individuals, hasn’t yet been peer-reviewed and is due to be published on Monday, the newspaper said. Patients in the randomized, double-blind study had a median age of 31.

“We do believe our vaccine could protect against severe disease, as neutralizing antibody activity is equivalent to that of other Covid-19 vaccines that have demonstrated activity against more severe disease, particularly when the dosing interval is optimized to 8-12 weeks,” the AstraZeneca spokesperson said.

Initial data indicates other immune responses, such as T-cell responses, may remain intact in the South African variant, the spokesperson added.

The variant first identified in South Africa is emerging as a key threat to the world’s prospects for ending the pandemic as countries roll out initial vaccine doses. Although vaccine makers said their shots appear to maintain effectiveness against the U.K. variants, pharma companies are racing to develop booster shots against new strains as the virus evolves.

Oxford University and AstraZeneca have started adapting their vaccine against this variant, the spokesperson said. Should it be needed, they will advance it through clinical development so that it’s ready for autumn delivery.

Sarah Gilbert, the Oxford professor leading work on the AstraZeneca shot, said “more data” will be published soon. Speaking to the BBC’s Andrew Marr show, she said it’s possible current vaccines won’t reduce the number of cases of the South Africa variant, but will reduce deaths, hospitalizations and severe cases of the disease.

“That’s really important for health-care systems. Even if we are having mild and asymptomatic infections, to prevent people from going into hospital with Covid would have a major effect,” Gilbert said.

U.K. Vaccines Minister Nadhim Zahawi said all the country’s vaccines do have “some effect” on the South African strain, as well as the British variant. “We deploy the vaccines we have, they offer that protection against serious illness, hospitalization and death, which is what we need to do,” he said in an interview with the BBC Sunday.

Earlier this week, Astra’s executive vice president for biopharmaceutical research scaled back expectations for how the vaccine would work against the variant.

“We’re not going to be surprised to see reduced efficacy,” Mene Pangalos said. “It’s to be expected that there will be reduced activity.”

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