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Post-Vaccination Symptomatic SARS-CoV-2 Infections are Minimal and Non-Serious: An Observational Multicenter Indian Cohort Study of 28342 Healthcare Workers

29 Pages Posted: 20 Jul 2021

See all articles by Raju Vaishya

Raju Vaishya

Indraprastha Apollo Hospitals

Anupam Sibal

Indraprastha Apollo Hospitals

Arpita Malani

Indraprastha Apollo Hospitals

Sujoy Kar

Apollo Hospitals

Hari Prasad K.

Apollo Hospitals Enterprises Ltd

Kiran SV

Apollo Hospitals Enterprises Ltd

Sangita Reddy

Apollo Hospitals Enterprises Ltd

Shobana Kamineni

Apollo Hospitals Enterprises Ltd

Suneeta Reddy

Apollo Hospitals Enterprises Ltd

Preetha Apollo Reddy

Apollo Hospitals Enterprises Ltd

Prathap Chandra Redddy

Apollo Hospitals Group

More...

Abstract

Background: The healthcare workers (HCWs) have been on the frontline in combating the pandemic and were prioritized for vaccination when COVID-19 vaccines became available. Although vaccines effectively prevent infection in most cases, some cases of post-vaccination infections have been reported, raising concerns about vaccine efficacy. This study investigated the efficacy of COVID-19 vaccines in preventing and reducing the severity of post-vaccination infections (PVI) among HCWs.

Methods: This observational study examined 28342 vaccinated HCWs with SARS-CoV-2 (symptomatic severe acute respiratory syndrome coronavirus 2) infections during the initial five months of vaccination (January 16-June 15, 2021). They worked at 43 Apollo Group hospitals in 24 Indian cities. PVI was investigated after recombinant ChAdOx nCOV-19 (Recombinant) or the whole virion inactivated Vero cell vaccines were administered. Various parameters were evaluated such as age, sex, time to infection, type of vaccine, infections after a single and two doses, monthly and regional case distribution, clinical severity of infection, hospitalization and intensive care unit (ICU) requirement, and death.

Findings: Symptomatic PVIs occurred in a low percentage of vaccinated cohorts (5⸱07%, p<0⸱001), and these were predominantly mild and did not result in hospitalization, ICU admissions (p<0⸱0001), or death. Both vaccines provided similar protection, with PVI incidences of 5⸱11% and 4⸱58%, following  ChAdOx nCOV-19 (Recombinant) and the whole virion inactivated Vero cell vaccines, respectively (p<0⸱001). Nursing and Clinical staff and cohorts>50 years significantly contracted more infections(p<0⸱001 and p=0⸱001, respectively). Two-dose vaccination has significantly lower odds of developing PVI (0.83, 95%CI – 0.72 to 0.97). Maximum infections occurred during the peak of the second COVID-19 wave from mid-April to May 2021 (p<0⸱001). No significant difference existed in the infection between sex, vaccine type, and the number of vaccine doses received (p≥0⸱05).

Interpretation: PVI occurred in a small percentage of HCWs. Vaccination protected them significantly from the infection but also severe disease.

Funding Information: None.

Declaration of Interests: None.

Ethics Approval Statement: This study was approved by an Ethical Institutional Committee (EIC), and a consent waiver was given by the EIC.

Suggested Citation

Vaishya, Raju and Sibal, Anupam and Malani, Arpita and Kar, Sujoy and K., Hari Prasad and SV, Kiran and Reddy, Sangita and Kamineni, Shobana and Reddy, Suneeta and Reddy, Preetha Apollo and Redddy, Prathap Chandra, Post-Vaccination Symptomatic SARS-CoV-2 Infections are Minimal and Non-Serious: An Observational Multicenter Indian Cohort Study of 28342 Healthcare Workers. Available at SSRN: https://ssrn.com/abstract=3889352 or http://dx.doi.org/10.2139/ssrn.3889352

Raju Vaishya (Contact Author)

Indraprastha Apollo Hospitals ( email )

New Delhi
India

Anupam Sibal

Indraprastha Apollo Hospitals ( email )

New Delhi
India

Arpita Malani

Indraprastha Apollo Hospitals

New Delhi
India

Sujoy Kar

Apollo Hospitals ( email )

Jubilee Hills Hyderabad
India

Hari Prasad K.

Apollo Hospitals Enterprises Ltd

Jubilee Hills Hyderabad
India

Kiran SV

Apollo Hospitals Enterprises Ltd

Jubilee Hills Hyderabad
India

Sangita Reddy

Apollo Hospitals Enterprises Ltd

Jubilee Hills Hyderabad
India

Shobana Kamineni

Apollo Hospitals Enterprises Ltd

Jubilee Hills Hyderabad
India

Suneeta Reddy

Apollo Hospitals Enterprises Ltd

Jubilee Hills Hyderabad
India

Preetha Apollo Reddy

Apollo Hospitals Enterprises Ltd

Jubilee Hills Hyderabad
India

Prathap Chandra Redddy

Apollo Hospitals Group

Jubilee Hills Hyderabad
India

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