JOIN USPhase 1 trial results show Covaxin has tolerable safety, enhanced immunity: Lancet study
Covaxin has affected enhanced immune responses against Covid-19, a paper published in the famous medical journal Lancet has stated, citing the phase-1 trial results of Bharat Biotech and ICMR- National Institute of Virology developed the vaccine.
However, the interim report does not provide data on the persistence of vaccine-induced antibody responses or long-term safety outcomes.
“The results reported here do not permit efficacy assessments. The analysis of safety outcomes requires more extensive phase 2 and 3 clinical trials,” said the peer-reviewed study, whose contributors include Bharat Biotech CMD Krishna Ella, ICMR director general Balram Bhargava, AIIMS New Delhi director Randeep Guleria and others.
The homegrown vaccine, presently undergoing phase-3 trials, was accorded emergency use authorisation by the central drug regulator, along with Covishield developed by Oxford University-AstraZeneca, and manufactured by the Serum Institute of India, Pune.
Even as a section of experts and political leaders expressed doubts about the efficacy of Covaxin, the Narendra Modi government has been endorsing the indigenous vaccine and gave an initial order of 55 lakh doses. The Hyderabad-based company has dispatched the vials to various states. It is not clear as to how many healthcare workers have received the Covaxin dose.
On Friday, Bharat Biotech's joint managing director Suchitra Ella announced that phase-3 second dose was administered on 13,000 volunteers – halfway mark. The company claims the participation of about 26,000 volunteers “is the largest phase-3 efficacy trial ever conducted for any vaccine in India.”
Suchitra referred to the Lancet report on Covaxin phase-1 studies as “the first clinical trial publication on a Covid-19 vaccine from India.”
The Lancet article says that BBV152 (Covaxin) was well tolerated in all dose groups with no vaccine-related serious adverse events. “BBV152 induced binding and neutralising antibody responses that were similar to those induced by other SARS-CoV-2 inactivated vaccine candidates.”
Conducted in July at 11 hospitals across India, Phase-1 was a double-blind, randomised, controlled trial to assess the safety and immunogenicity of Covaxin.
While 827 participants were screened, 375 were enrolled for vaccination. 100 each were randomly assigned to the three vaccine groups, and 75 were randomly assigned to the control group (Algel only).
The study population did not have ethnic diversity and most of the participants were men, further underscoring the importance of assessing BBV152 in other populations, the report says.
BBV152 is the first inactivated SARS-CoV-2 vaccine that has been reported to induce a Th1-biased response. BBV152 can be stored at 2–8°C, which is compatible with immunisation cold-chain requirements. Both Algel-IMDG formulations were selected for the phase 2 immunogenicity trials. Further efficacy trials are warranted, the authors state.