Covaxin safe, can be stored at 2-8°C, says Lancet report

Bharat Biotech announced earlier this month that preliminary results show Covaxin has an efficacy of 81% in phase 3 clinical trial amid months of speculations to rest.

Covaxin, made by Hyderabad-based Bharat Biotech International Limited, has been declared "safe, immunogenic with no serious side effects" by Lancet, which has published its phase 2 results. Lancet also said that efficacy cannot be determined by phase 2 trials. “We report interim findings of the phase 2 trial on the immunogenicity and safety of BBV152, with the first dose administered on day 0 and the second dose on day 28,” the report published on Monday said.

The Lancet study enrolled a small number of participants aged 12-18 years and 55-65 years. (Bloomberg)

Covaxin induced high neutralising antibody responses that remained elevated in all participants at 3 months after the second vaccination in the Phase 1 trial, it said. “In the phase 2 trial, BBV152 showed better reactogenicity and safety outcomes, and enhanced humoral and cell-mediated immune responses compared with the phase 1 trial. The 6 μg with Algel-IMDG formulation has been selected for the phase 3 efficacy trial,” it said.

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“BBV152 (developed using a well established manufacturing platform) was safe, immunogenic (persisting for 3 months), and can be stored at 2–8°C, which is compatible with the immunisation cold chain requirements of most countries. Follow-up studies to assess efficacy and immune responses in older adults and in people with comorbidities are underway,” it added.

The Lancet study enrolled a small number of participants aged 12-18 years and 55-65 years. “Follow-on studies are required to establish immunogenicity in children and in those aged 65 years and older,” it said noting the study population lacked ethnic, racial, and gender diversity, “further underscoring the importance of evaluating BBV152 in other populations.”

The Lancet report says the results reported in the study of phase 2 results do not permit efficacy assessments and the “evaluation of safety outcomes requires extensive phase 3 clinical trials.” "We were unable to assess other immune responses (ie, binding antibody and cell-mediated responses) in convalescent serum samples due to the low quantity. Furthermore, no additional data on the age of the participant or the severity of disease from symptomatic individuals were obtained. Comparisons between phase 1 and 2 trials were not done in a randomised set of participants, and no adjustments on baseline parameters were made. Conclusions are to be considered as post-hoc analyses," it said.

Bharat Biotech announced earlier this month that preliminary results show Covaxin has an efficacy of 81% in phase 3 clinical trial amid months of speculations to rest. “Today is an important milestone in vaccine discovery, for science and our fight against coronavirus disease. 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. Covaxin demonstrates a high clinical efficacy trend against Covid-19 but also significant immunogenicity against the rapidly emerging variants,” Krishna Ella, Bharat Biotech’s chairman and managing director, said.

Prime Minister Narendra Modi opted to get a dose of the home-grown vaccine on March 1 when the country's second phase of the vaccination drive began.

India recorded 15,388 new cases of the coronavirus disease in the last 24 hours, which has taken its tally to 11,244,786, according to the Union ministry of health and family welfare on Tuesday. There were 77 fresh fatalities in the same period, which pushed the death toll to 1,57,930, according to the health ministry.