AZ-Oxford vaccine safe & efficacious: Interim analysis

New Delhi: An interim analysis of the Covid-19 vaccine developed by AstraZeneca and Oxford University reveals that it is safe and efficacious, leading medical journal Lancet has reported.
“ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic Covid-19 in this interim analysis of ongoing clinical trials,” the Lancet said.

The study involving 23,848 participants was conducted between April 23 and November 4, 2020. The analysis included data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa.

The participants were recruited and vaccinated across the four studies. “We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials,” the report said.

Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline).

Participants in the ChAdOx1 nCoV-19 group received two doses, while a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose.

In participants who received two standard doses, “vaccine efficacy was 62.1% and in participants who received a low dose followed by a standard dose, efficacy was 90.0%. Overall vaccine efficacy across both groups was 70.4%,” it said.