None of the 11 COVID-19 vaccine candidates currently in human clinical trials worldwide, including India-made COVAXIN and ZyCov-D, are likely to be ready for mass use before 2021, the Ministry of Science and Technology said Sunday afternoon.

The ministry's statement comes amid row over letter by ICMR (Indian Council for Medical Research) setting August 15 - Independence Day - as the target for developing and releasing a viable novel coronavirus vaccine.

The press release earlier stated that along with the two Indian vaccines -- Covaxin and ZyCov-D -- 11 out of 140 vaccine candidates have entered the human trials across the globe and added that neither of these is likely to be ready for mass use before 2021.

Moments after, the statement was edited, and the line stating 'vaccines are unlikely to be ready before 2021,' was removed. The fresh release does not mention the statement in the same paragraph where it stood before.

India's apex medical body ICMR on Friday had said that it aims to launch the world's first Covid-19 vaccine, the indigenously developed Covaxin, by August 15, and has told select medical institutions to fast-track its clinical trial approvals. But experts said such a timeline may not be realistic.

In a letter, Director General of the ICMR Balram Bhargava said human trials for the coronavirus vaccine (Covaxin), that is being developed by Bharat Biotech and the ICMR, should be "fast-tracked".