There is “still some hope” that the Oxford/AstraZeneca Covid-19 vaccine could perform in people infected with the variant first identified in South Africa who are at risk of severe disease, Shabir Madhi, professor of vaccinology at the University of the Witwatersrand said on Monday.
Early data from South Africa’s University of Witwatersrand released on Sunday suggested that two doses of the Oxford/AstraZeneca Covid-19 vaccine provide only “minimal protection” against mild and moderate Covid-19 from the B.1.351 variant.
“What the study results really tell us is that in a relatively young age demographic with very low prevalence of morbidities such as hypertension and diabetes, the (Oxford/AstraZeneca) vaccine does not protect against mild to moderate infection,” Madhi, who led the trial, told the BBC.
Madhi added that “extrapolating” from results seen with the Johnson & Johnson Covid-19 vaccine -- which is also a viral vector vaccine -- there was “still some hope” that the Oxford/AstraZeneca vaccine could perform “as well” in different age groups at risk of severe disease.
“Now these two vaccines use a similar sort of technology," Madhi explained.
"They use them very, very similar in terms of the immunogenicity so I think extrapolating from that, there's still some hope that the AstraZeneca vaccine might well perform as well as the Johnson & Johnson vaccine in a different age group demographic that are at risk of severe disease,” he said.
Results from trials in South Africa showed Johnson & Johnson's single-dose vaccine reduced severe disease by 89%, Madhi said.
He also said that researchers should know with more certainty “pretty soon.”
On Sunday, South African health officials said they were pausing the country's rollout of the Oxford/AstraZeneca vaccine after the study showed it offered reduced protection from the Covid-19 variant first identified there.