Effectiveness of BBV152/Covaxin and AZD1222/Covishield Vaccines Against Severe COVID-19 and B.1.617.2/Delta Variant in India, 2021: A Multi-Centric Hospital-Based Case-Control Study

Tarun Bhatnagar,Satyendra Khichar,Ravisekhar Gadepalli,Nivedita Gupta,Naveet Wig,Priya Abraham,Puneet Misra,G Vijaykrishnan,Binod Kumar Patro,Ashish Surana,Monika Pathania,Jeromie Wesley Vivian Thangaraj,Mahendra Kumar Garg,Dinesh Babu,Savita Patil,Ashwini Agarwal,Anil Kumar,Farzana Islam,Randeep Guleria,Sangita Bhalavi,Lalit Dar,Vineet Jain,Anjan Trikha,Pankaj Bhardwaj,Basavana Gowdappa,Yasir Alvi,Triparna Majumdar,Yogesh Bahurupi,Sanjeev Misra,Sunil Kohli,Priyamadhaba Behera,Naimesh Shah,Nishant Kumar Chauhan,Santhosh Kumar Muthusamy,Deepak Shukla,Sirshendu Chaudhuri,R Sabarinathan,Rajendra Joshi,Mridu Dudeja,Jaykaran Charan,Manisha Dudhmal,Baijayantimala Mishra,Smita Sinha,Sitanshu Sekhar Kar,Vartika Saxena,Shashi Kant,Abhinendra Kumar,Deepak Kumar,Mahalingam Venkateshan,Rahul Dhodapkar,Ramniwas Jalandra,Minakshi Dhar,R Deepashree,Meenakshi Khapre,Deepjyoti Kalita,Sarita Wadhava,Kb Chetak,Akhil Dhanesh Goel,Sarika P Kombade ,Rima R Sahay ,Prakash Patel ,Amoghashree ,K Sanjay ,Uday Narlawar ,P Ashok ,Dipu Ts ,Manish Patel ,Mr Narayana Murthy ,Priyanka Pandit Biswas ,Prasanta Raghab Mohapatra ,Faheem Ahmed ,Dimpal A Nyayanit ,Mannu Jain ,Anil S Bilimale ,Kiran G Kulirankal ,M Shwethashree ,Pragati Rathod ,Anita M Shete ,Pragya Yadav ,M Jawahar ,Palanivel Chinnakali ,Aswathy Sreedevi ,Arvind Kumar Singh ,A V Gayathri ,Manickam Ponnaiah ,K.v Leela ,Ayan Kumar Das ,M Logaraj ,Manoj Kumar Gupta ,A Tejashree ,Manoj Murhekar

doi:10.2139/ssrn.3955739

Abstract

Background: India introduced BBV152/Covaxin and AZD1222/Covishield vaccines from January 2021. We estimated effectiveness of these vaccines against severe Coronavirus disease 2019 (COVID-19) among individuals aged >=45 years.Methods: We did a multi-centric, hospital-based, case–control study between May and July 2021. Cases were severe COVID-19 patients and controls were COVID-19 negative individuals from 11 hospitals. Vaccine effectiveness (VE) was estimated for full (2 doses ≥14days) and partial (1 dose ≥21 days) vaccination; duration between two vaccine doses and against the Delta variant. We used a random effects logistic regression model to calculate adjusted odds ratios (aOR) with 95% CI after adjusting for relevant known confounders.Findings: We enrolled 1,143 cases and 2,541 controls. The VE of full vaccination was 80% (95% CI: 73%-86%) with AZD1222/Covishield and 69% (95% CI: 54%-79%) with BBV152/Covaxin. The VE was highest for a gap of 6-8 weeks between two doses of AZD1222/Covishield (92%, 95% CI: 82%-96%) and BBV152/Covaxin (92%, 95% CI: 26%-99%). The VE estimates were similar against the Delta strain and sub-lineages.Interpretation: BBV152/Covaxin and AZD1222/Covishield were effective against severe COVID-19 among the Indian population during the period of dominance of highly transmissible Delta variant in second wave of pandemic. An escalation of two-dose coverage with COVID-19 vaccines is critical to control the pandemic in the country.Funding Information: Indian Council of Medical ResearchDeclaration of Interests: None to declare. Ethics Approval Statement: We obtained written informed consent from all the participants or their legally authorized representatives. Study procedures were approved by the Institutional Human Ethics Committees of all participating institutions.

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