Indian drugmaker Bharat Biotech has slammed a recent comparative study of antibodies produced by its vaccine Covaxin vis-à-vis Serum Institute of India's locally produced Covishield.
Covaxin is the indigenously manufactured vaccine by Hyderabad-based Bharat Biotech in collaboration with ICMR and the National Institute of Virology (NIV).
Saying that the study has "lots of flaws," a Bharat Biotech statement said, "A recent comparative report on 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."
The unpublished study, conducted on 515 healthcare workers (425 Covishield and 90 Covaxin recipients), and recently uploaded on preprint server MedRxiv said Covishield recipients were found to have a higher sero positivity rate and average rise in anti-spike antibody (ASA) than those who got Covaxin.
Bharat Biotech’s statement added that “this report is not a peer-reviewed publication, nor statistically & scientifically designed study, the study design & conduct reflect an ad hoc analysis, rather than predetermined hypothesis. Further, the study was not registered on CTRI website, nor approved by CDSCO & SEC.”
"It is critical to understand the Phase-3 data will first be submitted to CDSCO, followed by peer reviewed journals, with a timeline of 3 months for publication, and as communicated earlier COVAXIN phase 3 results full trial data
will be made public during July: Bharat Biotech."
Bharat Biotech’s SARS-CoV-2 project lead Dr Raches Ella @RachesElla had tweeted "…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.”
Another tweet from Dr Ella said, “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.”
Dr Ella tagged the study's lead author Dr A.K. Singh and said medical journal Lancet recommends authors refrain from actively seeking media attention for articles which are not peer reviewed.
Dr Singh tweeted: “Brother, whole country is getting vaccinated even without a preprint phase 3 results – lest forget published one. We owe a sincere gratitude to Bharat Biotech but that does not mean one should raise finger on others effort. Of course, we will produce published results finally.”
On June 8, Suchitra Ella, who heads business development and advocacy (joint managing director) at Bharat Biotech, tweeted that Covaxin had got “Brazil - Anvisa audit approval”.
She tweeted the announcement that regulatory approvals for Covaxin are in process in 60 countries, including the US, Brazil, Hungary, etc. And that emergency use authorisation (EUA) has been obtained in 13 countries with more to follow.
While Bharat Biotech’s statement found support among Twitter users, many others demanded that Bharat Biotech publish Covaxin's phase three results before trying to point out shortcomings in studies conducted by others.
Abhishek @the_malakas replying to @ANI tweeted, "It's nothing but a hitjob against covaxin, and I'm glad that Bharat Biotech has responded. But it needs to produce the result of trials which it conducted against the delta and alpha variants to keep these hitjobs away."
Twitter user Navroop Singh @NavroopSingh_ came out in support of Covaxin and tweeted that “COVAXIN doing great against immune escape variants two studies out today one against B.1.315 (Beta) & Delta (B.1.617.2) & other against the new variant discovered by NIV Pune B.1.1.28 P2. Variant. Kudos @BharatBiotech Flag of India#COVAXIN.
On June 9, a joint study conducted by researchers from Pune’s National Institute of Virology, the Indian Council of Medical Research (ICMR), and Bharat Biotech stated that Covaxin is effective against the Beta and the Delta variants of coronavirus. The study has been conducted based on samples from 20 people who have recovered from COVID-19 and 17 others who have received both doses of Covaxin. The authors of the report include ICMR chief Balram Bhargava.
The government on June 8 had placed fresh orders for 44 crore COVID-19 vaccines following the change in the national vaccination policy announced by the Prime Minister on June 7. These orders are to be supplied between August and December with 25 crore Covishield doses and 19 crore doses of Covaxin.