The phase 2 human clinical trial of the Oxford Covid-19 vaccine candidate in the country by Pune-based Serum Institute of India (SII) started today.

The observer-blind, randomised controlled study to determine the safety and immunogenicity of ``Covishield`` on healthy Indian adults will begin at Bharati Vidyapeeth Medical College and Hospital in Pune.

Serum Institute of India has partnered with British-Swedish pharma company AstraZeneca for manufacturing the Covid-19 vaccine candidate, developed by the University of Oxford.

Initial results of the first two-phases of trials of the vaccine conducted in five trial sites in the UK showed it has an acceptable safety profile and homologous boosting increased antibody responses, sources had said.