Phase 3 of Covaxin trials kick off at AIIMS, neurology chief gets first dose

Unlike the phase 1 and 2 trials, people from the general population – including the young, the old and the comorbid – will be given the vaccine in Phase 2 and not just healthy volunteers.

Phase 3 trials of the indigenously developed Covaxin kicked off on Thursday at the All India Institute of Medical Sciences (AIIMS), with the vaccine being given to the head of the department of neurology Dr MV Padma Shrivastava.

The people who are administered the vaccine will be followed up for a period of 207 days by researchers. (REUTERS)

Unlike the phase 1 and 2 trials, people from the general population – including the young, the old and the comorbid – will be given the vaccine in Phase 2 and not just healthy volunteers.

The large scale phase 3 trials will recruit over 26,000 volunteers from 25 trial sites across the country. In Delhi, doctors from AIIMS will administer the two dose vaccine, developed by an Indian vaccine maker in collaboration with the Indian Council of Medical Research, to 3,000 persons in Delhi’s Dakshinpuri.

“The first person to be enrolled for the phase 3 trial has received the first shot today. Another shot will be given a month later. We hope to complete the enrolment of 3,000 persons within a month. Volunteers would be selected from among AIIMS employees and from a site we have in Dakshinpuri. That will ensure that we are able to do proper follow-ups,” said Dr Puneet Mishra, professor, department of community medicine, AIIMS. He is one of the investigators of the vaccine trial.

“It is my institute’s trial and my country’s product. It is an honour to participate in the trial. All medicines that come into the market have to go through the trial. I understand the science; it is a placebo controlled trial and no one will know who gets the vaccine and who does not, and I am happy to play my part,” said Dr MV Padma Srivastava. The doctor vouched that she is over the age of 60 years and has no comorbidities.

Vaccine candidates have to be tested on animal models first to check their safety and immune response. In humans, a small phase 1 trial is done to check the safety of the compound, while in phase 2, trials are done to see the immune response and the dose at which the vaccine should be administered.Large scale phase 3 trials are done to see how many infections or severe disease the vaccine prevents in a given population.

“The recruitment should be complete within a month and we will start seeing some preliminary data by that time,” said Dr Mishra.

The people who are administered the vaccine will be followed up for a period of 207 days by researchers. The vaccine uses an inactivated Sars-Cov-2 virus to generate an immune response that can prevent Covid-19 disease. The preliminary data, which can be presented to the drug regulator for seeking emergency use authorisation, should be available within two months, the researcher said.

The doctor said so far, none of the participants in the phase 1 and 2 trials has had any adverse events, although there have been news reports of a volunteer from Nagpur developing viral pneumonia or inflammation of the lungs.

“Some participants have just experienced redness and pain at the injection site, but that is common to many injectables,” said Dr Mishra.

Four vaccine candidates from around the world have announced preliminary reports this week – trial data from US Pfizer and Moderna and Russian Sputnik V show their vaccines were about 95% effective at preventing Covid-19, while AstraZeneca/ Oxford say its vaccine could be up to 90% effective with a particular half dose first and a full dose later.

Apart from Covaxin, ZyCovD developed by Indian pharmaceutical company Zydus is also in advanced stages of human trials.