Covaxin Vaccine Update: What is know so far about phase 3 trial, efficacy, protection against new Covid strain

Covid vaccine in India Covaxin latest update: India has formally granted “Restricted Emergency approval” to Covaxin and Covishield COVID-19 virus vaccines paving the way for immediate vaccination against the highly contagious disease. Bharat Biotech’s Covid-19 vaccine needs to be administered in two doses and has to be stored at 2 degree celsius to 8 degree Celsius. Bharat Biotech has developed Covaxin in collaboration with the Indian Council of Medical Research (ICMR) and the National Institute of Virology, Pune (NIV).

Covaxin Efficacy

India’s first indigenous Coronavirus vaccine is facing queries over its efficacy against the Covid-19 virus. Drugs Controller General of India (DCGI) has issued licensing permission to Bharat Biotech to manufacture Covaxin. However, the DCGI has been directed Bharat Biotech to submit updated safety, efficacy, and immunogenicity data from the ongoing Phase I, II, and Ill human trials till the completion of trials of Covaxin.

ICMR, in a statement, said that data generated through pre-clinical studies and several phases of the human trials of Covaxin conducted across India underlined its safety and immunogenicity.

Bharat Biotech has developed a “Whole Virion Inactivated Corona Virus Vaccine” (Covaxin) in collaboration with ICMR and NIV (Pune), from where they received the virus seed strains. This vaccine is developed on Vero cell platform, which has a well-established track record of safety and efficacy in the country and globally, the Ministry of Health and Family Welfare said in a statement.

Drugs Controller General of India VG Somani has assured that the DCGI would never “approve anything if there is slightest of safety concern”. Both Covishield and Covaxin vaccines are 100 per cent safe, he said. Dr. Somani has assured that some side effects like mild fever, pain, and allergy are common for every vaccine. He has also rejected that people may get impotent due to vaccination terming it “absolute rubbish”.

World Health Organization (WHO) has welcomed India’s decision giving emergency use authorization to COVID19 vaccines, Regional Director of WHO-South-East Asia Region Dr. Poonam Khetrapal Singh said.

Covaxin phase 3 trial

Bharat Biotech has generated safety and immunogenicity data of Covaxin in various animal species such as mice, rats, rabbits, Syrian hamster, and also conducted challenge studies on non-human primates (Rhesus macaques) and hamsters. All these data have been shared by the firm with CDSCO. Phase I and Phase II clinical trials were conducted in approx. 800 subjects and the results have demonstrated that the vaccine is safe and provides a robust immune response. The Phase III efficacy trial was initiated in India in 25,800 volunteers and till date, around 22,500 participants have been vaccinated across the country and the vaccine has been found to be safe as per the data available till date, the Ministry of Health and Family Welfare said in a statement.

Covaxin protection against new Covid strain, variant

The Subject Expert Committee (SEC) has reviewed the data on safety and immunogenicity of the vaccine and recommended for grant of permission for restricted use in an emergency situation in the public interest as an abundant precaution, in clinical trial mode, to have more options for vaccinations, especially in case of infection by mutant strains. The clinical trial ongoing within the country by the firm will continue, the Ministry of Health and Family Welfare said in the statement.

AIIMS Delhi Director Randeep Guleria said that Bharat Biotech’s Covaxin will be used in an emergency situation when there is a sudden increase in cases. Covaxin can also be used as a ‘backup’ “when we’re not sure how efficacious the Serum Institute vaccine is going to be,”, Guleria said. Guleria said that the government of India’s approval clearly stated ’emergency situation’ keeping in mind the circulating variant strains and at the same time, Bharat Biotech needs to continue the trial and get the data in. “Once that data comes in, we’ll be more confident as far as safety and efficacy is concerned,” Guleria said.

DG ICMR, Dr. Balram Bhargava said, new the strain of Covid-19 is a “whole virus”. India-made vaccines target all the proteins on the surface of the virus, not just one S-GEN protein that has mutated. Therefore those vaccines that are targeting just the ‘SGEN’ may not work as well, he said adding that it was still scientific conjecture. “We hope potentially Bharat Biotech vaccine will have some advantages over other vaccines on this new strain because it is a whole virus,” Dr. Bhargava said.