Can you trust Covaxin data?

The good news is that Bharat Biotechs Covaxin safety and efficacy analyses data in trial III has been announced and the vaccine was found to have 778 per cent efficacy and nearly 65 per cent efficacy for the Delta variants But health care experts differ on this While some have lauded the outcome of the results others said that unless appropriate immunological studies are documented it is impossible to judge the efficacy of any vaccineThe Covaxin vaccine Phase 3 controlled clinical trial on 25800 volunteers was conducted in India in 25 hospitals Although the interim analysis done in March 2021 had shown the overall preventive efficacy at 81 per cent the recently submitted final data analysis to the DCGI worked out to 778 per cent The vaccine was well tolerated and did not report any serious side effects including deathsCovaxin has been evaluated through neutralizing antibody responses against several variants of concern namely B16172 Delta B16171 Kappa B117 Alpha B1351 Beta P2 B1128 Gamma Representation picAshish RajeldquoThe stratified analysis of the final data reportedly showed that Covaxinrsquos preventive efficacy was 934 per cent towards occurrence of severe Covid19 and 636 percent towards that of asymptomatic infection It provided almost 65 per cent protection against the Delta variants prevalent in India during the early part of 2021 This possibly did not include Deltaplus variants that started to appear in India in AprilMay 2021 The latter is not a major lacuna in the Covaxin study because viral mutations are a dynamic phenomenon and clinical trials do not necessarily track all dynamic occurrences But its a welcome step that Bharat Biotech and ICMR have submitted the final reports to the Drugs Controller General of India DCGI and the World Health Organisation WHO to satisfy monitoring and safety systems said Dr Subhash Hira professor of Global Health at the University of WashingtonSeattle and member invited to several WHO Covid review fora Although I have not seen the full report I feel that rapid evaluation of the report leading to the full license of DCGI will be important That should provide an opportunity to scale up its production for use both nationally and internationallyrdquo added Dr HiraDr Hira added ldquoMost developing countries are struggling to get Covid19 vaccines A vulnerable country like the Democratic Republic of Congo DRC with a population of 90 million people has administered vaccines to 45000 people This is despite the fact that its health systems have welltrained vaccinators who successfully injected Ebola vaccines into the entire eastern part of DRC a few years ago Covaxins scaledup production can help deliver the affordable vaccine to the Southern world without depriving India of suppliesrdquoHowever Dr Wiqar Shaikh professor of Medicine Grant Medical College and Sir JJ Group of Hospitals differed on the study He said that Bharat Biotech the makers of Covaxin have published the results of their Phase 3 trials in a nonpeer reviewed journal medRxiv Dr Shaikh said The paper discussing the results of the Phase 3 trials mentions that the efficacy of Covaxin was 778 per cent and notes the development of IgG antibodies following its administration But what is surprising is that there is no mention in the study of the more important memory T cells such as NK cells and the cytotoxic cells both of which are extremely significant in providing longterm immunity from Covid19Dr Shaikh quoted a study from the journal Nature in July 2020 in which data was used from patients who suffered from the SARSCoV1 SARS virus in 2003 and which induced a durable memory Tcell response which has lasted for more than 17 years These memory Tcells also proved to be effective against the current Covid19 virus SARSCoV2Dr Shaikh said that medRxiv has published a disclaimer as part of the article that clarifies the nature of the Covaxin study It said This article is a preprint and has not been certified by peer review It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practicerdquoHe emphasized that unless appropriate immunological studies are documented it is impossible to adjudge the efficacy of any vaccine Immunological data particularly of memory T cells is about efficacy against mutant variants such as the Delta variant Dr Shaikh concluded Unless we have robust data on vaccine induced memory T cells we will need to modify the vaccine against variants and may not have longterm benefits Besides an annual vaccine against Covid19 may need to be administered as in the case of influenzaAn email was sent to Bharat Biotech seeking comments on Dr Shaikhs remarks but no reply was received till the time of going to pressIn its official statement on the safety and efficacy of the trial III results Bharat Biotechs BBIL Chairman and Joint Managing Director Dr Krishna Ella said ldquoThe safety and efficacy readouts of Covaxin as a result of conducting the largest ever Covid19 vaccines trials in India establishes the ability of India and developing world countries to focus towards innovation and novel product development We are proud to state that innovations from India will now be available to protect global populationsrdquoCovaxin has been specifically designed to meet the needs of global distribution chains the requirements for which are more critical in low and middleincome countries It has been formulated to enable shipping and longterm storage at 28ordmC It is also formulated to adhere to a multidose vial policy thereby reducing open vial wastage and saving money to procurement agencies and governments alikeSuchitra Ella joint managing director Bharat Biotech said ldquoIt is a momentous day for everyone at Bharat Biotech as we announce the Final Phase3 results of Covaxin and its efficacy of 77837 We wish to thank ICMR NIVPune Virovax DSMB and the Adjudication Committee We earnestly thank our clinical trial sites principal investigators IQVIA and every participant who has reposed their faith in CovaxinWe sincerely thank all our employees for enduring work pressures through the pandemic and lockdown with 24x7 commitment amidst unprecedented number of physical challenges stress and continuous operations We specially thank our medical affairs team for leading the project the technical and marketing teams which have relentlessly worked to complete the clinical trials and coordination of 25 sites across the country since May 2020rdquoCovaxin has been evaluated through neutralizing antibody responses against several variants of concern namely B16172 Delta B16171 Kappa B117 Alpha B1351 Beta P2 B1128 Gamma The data from these studies has been extensively published in peer reviewed journals and available for review in the public domainProf Dr Balram Bhargava secretary Department of Health Research amp Director General Indian Council of Medical Research said ldquoI am delighted to note that Covaxin developed by ICMR and BBIL under an effective public private partnership has demonstrated an overall efficacy of 77837 in Indiarsquos largest Covid19 Phase 3 clinical trial thus far Our scientists at ICMR and BBIL have worked tirelessly to deliver a truly effective vaccine of highest international standards Covaxin will not only benefit the Indian citizens but will also immensely contribute to protect the global community against the deadly SARSCoV2 virus I am also pleased to see that Covaxin works well against all variant strains of SARSCoV2 The successful development of Covaxin has consolidated the position of Indian academia and industry in the global arenardquo778Percentage of efficacy of Covaxin