Bharat Biotech Calls Out ‘Covishield vs Covaxin’ Comparative Study, Adds That Report Had Lot Of Flaws

Bharat Biotech, a Hyderabad-based vaccine manufacturing company, called out a recent comparative study of antibodies generated by its vaccine Covaxin and Serum Institute of India's locally produced Covishield vaccine as per a report in Livemint.

"A recent comparative report on the evaluation of immunogenicity responses to spike protein after 1st and 2nd dose of Indian manufactured vaccines study had lots of flaws. The journal that stated comparative report said more antibodies produced by Covishield than Covaxin," Bharat Biotech said in a statement on Wednesday(9 June).

Bharat Biotech alleged that the study was "not a peer-reviewed publication, nor statistically and scientifically designed study."

"It's not a peer-reviewed publication, nor statistically & scientifically designed study, the study design and conduct reflect an ad hoc analysis, rather than predetermined hypothesis. Further, the study was not registered on CTRI website, nor approved by CDSCO & SEC," the company stated.

The study available on medRxiv states in its finding that from among the 515 HCW (305 Male, 210 Female), 95 per cent showed seropositivity after two doses of both vaccines. Of the 425 Covishield and 90 Covaxin recipients, 98.1 per cent and 80 per cent, respectively, had antibodies.

Bharat Biotech said that phase 3 result's complete trial data for COVAXIN would be made public during July.

The statement added, "Once data from final analysis of phase III studies are available, Bharat Biotech will apply for full licensure for COVAXIN."

Raches Ella, head of business development and advocacy at Bharat Biotech, questioned the media reports stating the aforementioned reports and tweeted, “@Teensthack @singhak_endo surprised that media/researchers are concluding based on non-peer-reviewed work. Limitation 1: Spike-based IgG's are not appropriate when evaluating Covaxin, which induces broad antibody responses to Spike, N, and M. Recommend live virus neutralization.”

He added, “Limitation 2: Past history of Covid was based on verbal response and not by a pre-vaccination IgG test. The study fails to account for asymptomatics (predominant presentation of Covid) and introduces misclassification bias. SARS-CoV-2 naïve participants may not be naïve after all.”