COURTESY HT JULY 17

100 register for clinical trials of Covid vaccine; 3 to receive doses
PGIMS-ROHTAK : 22 volunteers screened; 3 to receive doses by weekend; trials may not be over by Aug 15

Prayag Arora-Desai

prayag.desai@htlive.com

Gurugram : In the 10 days since PGIMS-Rohtak began enrolling subjects for clinical trials of Covaxin —the indigenous Covid-19 vaccine — close to 100 individuals from Haryana have registered to be a part of the study.

Officials at PGIMS Rohtak — one of at least 12 locations in the country selected to execute clinical trials of the indigenous vaccine — said 22 of these volunteers have already been screened for their medical history, and that at least three of them will receive a dose of the experimental vaccine by the weekend or early next week.

Covaxin is an indigenous Covid-19 vaccine, which is being developed by Bharat Biotech and the ICMR’s National Institute of Virology, Pune. It is one of the two Indian vaccine candidates that have received the Drug Controller General of India’s nod to proceed with the Phase-1 and Phase-2 human clinical trials. In Rohtak, the sample size for Phase-1 trials is expected to around 8 to 10 people, officials said.

Dr Dhruv Chaudhary, who is a part of a three-member team leading the clinical trials at PGIMS, Rohtak, said, “The first batch of volunteers have been screened. Eight individuals have undergone rigorous medical scrutiny to check whether or not they have been previously infected with the virus, whether they suffer from any ailments of the liver, lungs, or kidneys, and if they have any history of other infectious diseases. Three of these volunteers, who were found eligible, will receive a dose of the vaccine, possibly by the weekend. Another 14 people were screened on Thursday and their biochemical reports are awaited.”

Chaudhary explained that Phase 1 of human trials will involve a very small sample size, about 50 people from across four sites in the country, namely Delhi, Patna, Hyderabad and Rohtak. These sites have received the nod from the institutional ethics committees to carrying out the trials. “The subjects will be closely monitored for two hours after receiving the first vaccine, and will receive a second dose in two weeks if they do not show any adverse reactions, such as headaches, fever or vomiting,” he said.

Dr Savita Verma, professor at the department of pharmacology at Rohtak PGIMS, and a principal investigator of the study, said, “We are taking all precautions as per the Drugs and Clinical Trials Rules, 2019. We will take two blood samples from the initial subjects, one at the end of 28 days and one at the end of 42 days. If we see a fourfold increase in antibodies after giving the vaccine, only then can we say that the vaccine has immunogenic properties. We will first establish safety of the current and future subjects before progressing to Phase 2 of the trials,” she added.

In the first phase, subjects will be between the ages of 18 to 55, while in Phase-2, they will be between 12 and 60 years of age. For every four people that receives the vaccine, one subject will be given a placebo — in the form of a Japanese encephalitis vaccine. A total of 1,125 subjects are expected to participate in the trials nationally.

Verma also explained that Covaxin is an “inactivated” vaccine, which relies on using samples of the SARS-Cov-2 virus that have been isolated at the National Institute of Virology, Pune. “The vaccines consist of virus particles which have been rendered inactive or are unable to replicate. However, the antigens will give a signal to the immune system to produce immunoglobulins or antibodies. This is different from the other Indian vaccine candidate, which does not contain any attenuated virus particles, and instead only relies on messenger RNA to signal our immune system.”

Verma, Chaudhury, and a third co-investigator, who did not wish to be identified, declined to comment on whether these clinical trials will be completed by August 15. On July 2, ICMR chief Dr Balram Bhargava had instructed the 12 trial sites (including PGIMS Rohtak) to complete all clinical trials by August 15. “These things typically take time. We may be able to provide some preliminary data by then, as some of the subjects should have produced antibodies by August 15,” Verma said.