NEW DELHI: The Covid-19 vaccine developed by AstraZeneca-Oxford University is 79 per cent effective in preventing asymptomatic infection and 100 per cent effective against severe disease, a large-scale clinical trial in the US has shown.
Produced and marketed by the Serum Institute of India under the brand name Covishield, this vaccine has been the backbone of the vaccination drive in India so far. AstraZeneca published the first data from an interim safety and efficacy analysis of over 32,000 volunteers on Monday, accruing 141 and said that vaccine efficacy was consistent across ethnicity and age.
Notably, in participants aged 65 and over, efficacy was 80 per cent. This is good news for India where all above 60 are eligible, among a few other specified groups of people, to take the shots. In the trials, approximately 20 per cent of participants were 65 and over, approximately 60 per cent had co-morbidities associated with an increased risk for progression of severe Covid-19, such as diabetes, severe obesity or cardiac disease, said the company.
This AstraZeneca-led US phase 3 trial included two doses administered at a four-week interval. Previous trials showed that an extended interval of up to 12 weeks demonstrated greater efficacy, which was supported by immunogenicity data. This evidence suggests administration of the second dose with an interval longer than four weeks could further increase efficacy and accelerates the number of people who can receive their first dose.
The latest trial could pave the way for the vaccine’s approval in the US. Mene Pangalos, executive vice president, biopharmaceuticals R & D at the firm, said: “These results add to the growing body of evidence that shows this vaccine is well tolerated and highly effective.”