Chhattisgarh government says won't use Covaxin till phase three trial is over

Express News Service
NEW DELHI: India’s first homegrown Covid-19 vaccine Covaxin has been found to be nearly 81 % effective in preventing infection, an interim analysis of the data from the vaccine’s phase 3 clinical trial in 25,800 volunteers has shown. 

The first interim analysis is based on 43 cases, of which 36 cases of Covid-19 were observed in the placebo group while 7 cases were seen in the vaccine group, resulting in a point estimate of vaccine efficacy of 80.6%, said Bharat Biotech, the company which has developed the vaccine along with the ICMR. 

The Phase 3 study enrolled 25,800 participants between 18-98 years of age, including 2,433 over the age of 60 and 4,500 with comorbidities.

This is a significant result considering that Covaxin is already being used in the country’s massive Covid-19 vaccination drive already, which in addition to healthcare and frontline workers, now also covers senior citizens and people above 45 with serious ailments. 

According to sources, the data safety monitoring board of the trial unblinded the study only on Wednesday afternoon and details such as how many severe cases of the disease were reported in the two groups are now being analysed. 

Covaxin had received the restricted use authorisation, along with Serum Institute of India’s Covishield in January this year after which the first phase of the vaccination was started. The permission granted to the vaccine by the country’s apex drug regulator without efficacy data had triggered massive criticism and has resulted in slow acceptance of the vaccine in many states. 

The vaccine contains a whole virion inactivated SARS-CoV-2, produced in Vero cells. It is stable at 2 to 8°C (refrigerated) and is shipped in a ready-to-use liquid formulation that permits distribution using existing vaccine supply chain channels. It has a 28-day open vial policy thus reducing vaccine wastage by approximately 10-30%.

“Today is an important milestone in vaccine discovery, for science and our fight against coronavirus. With today’s results from our phase 3 clinical trials, we have now reported data on our Covid-19 vaccine from Phase 1, 2, and 3 trials involving around 27,000 participants,” said Krishna Ella, CMD of Bharat Biotech. 

He added that the vaccine, in addition to demonstrating high clinical efficacy trend against Covid-19, has also shown significant immunogenicity against the rapidly emerging variants. 

Analysis from the ICMR’s National Institute of Virology has indicated that vaccine-induced antibodies can neutralize the UK variant strains and other heterologous strains.

The company meanwhile said that it expects to share further details of the trial results as additional data become available. 

An additional interim analysis is planned for 87 cases, and the final analysis is planned for 130 cases. All data from the second interim and final analyses will be shared via pre-publication servers as well as submitted to a peer-reviewed journal for publication.