@article {Tsunduee008271, author = {Tenzin Tsundue and Tenzin Namdon and Tenzin Tsewang and Sonam Topgyal and Tashi Dolma and Dekyi Lhadon and Tsering Choetso and Tenzin Woesal and Tenzin Yangkyi and Amita Gupta and David Peters and Zorba Paster and Dawa Phunkyi and Tsetan Dorji Sadutshang and Richard E Chaisson and Kunchok Dorjee}, title = {First and second doses of Covishield vaccine provided high level of protection against SARS-CoV-2 infection in highly transmissible settings: results from a prospective cohort of participants residing in congregate facilities in India}, volume = {7}, number = {5}, elocation-id = {e008271}, year = {2022}, doi = {10.1136/bmjgh-2021-008271}, publisher = {BMJ Specialist Journals}, abstract = {Objectives This study aimed to determine the effectiveness of Covishield vaccine among residents of congregate residential facilities.Design A prospective cohort study in congregate residential facilities.Setting Dharamshala, Himachal Pradesh, India, from December 2020 to July 2021.Participants Residents of all ages in seven facilities{\textemdash}three monasteries, two old age homes and two learning centres{\textemdash}were enrolled.Exposures First and second doses of Covishield vaccine against SARS-CoV-2 infection.Main outcomes measures Primary outcome was development of COVID-19. Secondary outcome was unfavourable outcomes, defined as a composite of shortness of breath, hospitalisation or death. Vaccine effectiveness (\%) was calculated as (1-HR){\texttimes}100.Results There were 1114 residents (median age 31 years) participating in the study, 82\% males. Twenty-eight per cent (n=308/1114) were unvaccinated, 50\% (n=554/1114) had received one dose and 23\% (n=252/1114) had received two doses of Covishield. The point prevalence of COVID-19 for the facilities ranged from 11\% to 57\%. Incidence rates (95\% CI) of COVID-19 were 76 (63 to 90)/1000 person-months in the unvaccinated, 25 (18 to 35)/1000 person-months in recipients of one dose and 9 (4 to 19)/1000 person-months in recipients of two doses. The effectiveness of first and second doses of Covishield were 71\% (adjusted HR (aHR) 0.29; 95\% CI 0.18 to 0.46; p\<0.001) and 80\% (aHR 0.20; 95\% CI 0.09 to 0.44; p\<0.001), respectively, against SARS-CoV-2 infection and 86\% (aHR 0.24; 95\% CI 0.07 to 0.82; p=0.023) and 99\% (aHR 0.01; 95\% CI 0.002 to 0.10; p\<0.001), respectively, against unfavourable outcome. The effectiveness was higher after 14 days of receiving the first and second doses, 93\% and 98\%, respectively. Risk of infection was higher in persons with chronic hepatitis B (aHR 1.78; p=0.034) and previous history of tuberculosis (aHR 1.62; p=0.047).Conclusion Covishield was effective in preventing SARS-CoV-2 infection and reducing disease severity in highly transmissible settings during the second wave of the pandemic driven by the Delta variant.Data are available upon reasonable request. As the data are generated from communities of Tibetan refugees in India, they are sensitive. We will make the data available on reasonable request.}, URL = {https://gh.bmj.com/content/7/5/e008271}, eprint = {https://gh.bmj.com/content/7/5/e008271.full.pdf}, journal = {BMJ Global Health} }