Samples from the Oxford vaccine trial. (AP/File)

Two Indian vaccine candidates that have started human trials are progressing at great speeds. Dr Balram Bhargava, director general of Indian Council of Medical Research, announced on Tuesday that phase-I trials of these two candidates were all but over.

Bhargava said Hyderabad-based Bharat Biotech had completed its phase-I studies for its vaccine candidate at 11 of the 12 selected sites. The company had already started phase-II trials at these places. The other vaccine candidate, being developed by Ahmedabad-based Zydus Cadila, had also started phase-II trials at 11 sites, he said.

The two companies had begun injecting the participants for their vaccine candidates around July 15. Bharat Biotech was aiming to rope in around 1,125 participants in its phase I/II trials, while Zydus was targeting around 1,048 participants.

Both these companies had got approvals to carry out phase-I and phase-II trials at one go. In phase-I trial, the vaccine is tested for its safety in human beings, while in phase-II its ability to trigger immune response in human body is assessed. In normal times, each phase of trial takes up to several months to be completed.

Meanwhile, Russia’s candidate vaccine was reported to have completed phase-I human trials in the second week of July. According to a news report in the Russia’s TASS news agency at that time, the phase-II trials were started on July 13. It is not clear whether the phase-II trials have also declared to have been completed. Usually, each of these phases can take several months to be completed. But considering the prevailing emergency situation, vaccine trials are being fast-tracked across the world.

This rush to produce the vaccine is leading to a lot of discomfort. Over the weekend, while testifying before a panel of US lawmakers, Anthony Fauci, a top US public health expert and one of the most trusted voices on the Coronavirus epidemic, had expressed doubts over the vaccines being produced in China and Russia. A Chinese vaccine has already been approved for limited use, without going through phase-III trials. It is being administered only to army personnel right now.

HUNT FOR CORONAVIRUS VACCINE: THE STORY SO FAR

*More than 160 vaccine candidates in pre-clinical or clinical trials *23 of them in clinical trials *Six in final stages, phase-III of human trials *At least eight candidate vaccines being developed in India. Two of these have entered phase-I human trials.