SARS-CoV-2 infection risk in COVISHIELD (AstraZeneca-SII) Vaccinated Healthcare Workers in a Tertiary Cancer Care Centre of North-East India

COVID-19 vaccination of Healthcare workers and vulnerable groups remain priority in containing the spread of SARS-CoV-2 infection and health complications arising post COVID-19. In India, COVISHIELD is the major part of COVID-19 vaccination drive. post-vaccination SARS-CoV-2 infection risk and its impact on severity as well as mortality need to be assessed in vaccinated population. The study included 350 COVISHIELD vaccinated HCWs in tertiary cancer care centre of North-East India. A total of 16 symptomatic HCWs (4.57%) were confirmed as SARS-CoV-2 positive. Among SARS-CoV-2 positive FV HCWs none were positive within 14 days, 13.33 % within 15 to 30 days, 53.33% within 30 to 45 days, and 33.33% after 45 or more days. None of the SARS-CoV-2 positive HCWs required oxygen support or hospitalisation. We also found that 66.67% FV HCWs (n=10) had Ct values below 20, 20% (n=3) had Ct values in between 20-25 and 13.33% (n=2) had Ct values in between 30 to 35. In North-East India COVISHIELD FV HCWs HCW,SARS-CoV-2 infection and COVID-19 symptoms were mild. Majority of FV HCWs have RT-PCR COVID-19 positive Ct Value was below 20. SARS-CoV-2 infection occurred mostly after 15 days to 45 days or more post vaccination. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement None ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethics committee/IRB of Dr B. Borooah Cancer Institute waived ethical approval for this work. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes None, All data is available in the tables