Three more India-made Covid-19 vaccines to enter trials
Government-level talks are also underway on the Russian vaccine, which is among five to have been given early approval for use in people, said Dr Renu Swarup, secretary, department of biotechnology (DBT), which is the nodal agency coordinating the vaccine development initiatives in the country.Updated: Sep 26, 2020, 09:15 IST
Three more India-made Covid-19 vaccines are set to enter human trials, according to an official of the Union government’s department of biotechnology that is supporting the development of several experimental coronavirus vaccines in the country.
The new vaccine candidates are from Gennova Biopharmaceuticals, Biological E and Bharat Biotech, which has developed one of the two already in clinical trials. The fifth Indian vaccine candidate to clear preclinical phases is by Zydus Cadila.
“There are several vaccine candidates in different stages of development, some are at a very early stage. But three vaccine candidates are finishing up their pre-clinical study and will soon enter human trials,” said Dr Renu Swarup, secretary, department of biotechnology (DBT), which is the nodal agency coordinating the vaccine development initiatives in the country.
Swarup added that government-level talks are also underway on the Russian vaccine, which is among five to have been given early approval for use in people. Globally, there are 38 vaccine candidates in human trials, in addition to around 150 more that are undergoing testing in animal subjects.
Russia is the only country to have approved a Covid-19 vaccine, although experts have questioned the scientific wisdom of doing so without large scale safety and efficacy tests in large groups of people. In addition, emergency approval has been granted to four vaccines, two each by China and the UAE, for limited use among some people.
In addition to Bharat Biotech’s first vaccine candidate and the one by Zydus Cadila, a phase III trial of the vaccine candidate developed by Oxford university and British pharma company AstraZeneca is underway in India as part of a production- and testing deal with Pune-based Serum Institute of India (SII).
The three vaccines Swarup referred to follow separate mechanisms to elicit and immune system response.
Gennova’s shot uses the mRNA platform, which works by inserting a genetic code to prompt the body into making copies of what is known as the antigen protein. The antigen protein is a portion of the Sars-Cov-2 virus (the pathogen that causes Covid-19), which trains the body into recognising and fighting the pathogen.
So far, no mRNA vaccines have been approved across the world but one of the leading Covid-19 vaccine candidates, from Moderna, uses the same platform.
The Biological E vaccine uses a protein subunit — which involves injecting an isolated protein of the virus to prime the immune system. The second Bharat Biotech candidate uses an inactivated rabies virus to deliver a viral protein of Sars-CoV-2 to achieve the same effect.
Bharat Biotech’s first candidate uses an inactivated version of Sars-Cov-2, a strategy that is one of the oldest to develop vaccines. Zydus Cadila’s vaccine uses a DNA plasmid to replicate portions of Sars-Cov-2 to teach the body to recognise it.
According to a submission in Lok Sabha in the monsoon session, DBT has allocated ₹75 crore to support at least eight vaccine candidates in the country.
For testing whether a vaccine candidate works, pre-clinical studies are done in animals to see whether it is safe and can produce immune response. This is followed by a small phase I trial to study safety in humans, a phase II trial to see whether it produces an immune response, and large phase III trial to see whether the vaccine can actually prevent the disease. Both phase II and phase III trials also focus on safety.
Swarup said that data from clinical trials of a plant-based pharmaceutical product and whether the anti-tubercular BCG vaccine protects against Covid-19 will start coming in too.
“The initial study of the phytopharmaceutical should start coming in soon, the data is being analysed. As for the study to see whether BCG is protective against Covid-19, the vaccines have already been administered and the follow-up has started. The initial data should start coming in from this study as well,” said Dr Swarup.
Several studies, including one by scientists from JNU, has shown that the BCG vaccine does increase protection against Covid-19.