The Effectiveness of SARS-CoV-2 Vaccination in Preventing Severe Illness and Death - Real-world Data from a Cohort of Patients Hospitalized with COVID-19

Hari Krishna Raju Sagiraju; Arunmozhimaran Elavarasi; Nishkarsh Gupta; Rohit Kumar Garg; Saurav Sekhar Paul; Saurabh Vig; Prashant Sirohiya; Brajesh Ratre; Rakesh Garg; Anuja Pandit; Ram Singh; Balbir Kumar; Ved Prakash Meena; Naveet Wig; Saurabh Mittal; Sourabh Pahuja; Karan Madan; Nupur Das; Tanima Dwivedi; Ritu Gupta; LaxmiTej Wundavalli; Angel Rajan Singh; Sheetal Singh; Abhinav Mishra; Manisha Pandey; Karanvir Singh Matharoo; Sunil Kumar; Anant Mohan; Randeep Guleria; Sushma Bhatnagar

doi:10.4103/ijcm.ijcm_1388_21

The Effectiveness of SARS-CoV-2 Vaccination in Preventing Severe Illness and Death - Real-world Data from a Cohort of Patients Hospitalized with COVID-19

Indian J Community Med. 2022 Oct-Dec;47(4):510-516. doi: 10.4103/ijcm.ijcm_1388_21. Epub 2022 Dec 14.

Authors

Hari Krishna Raju Sagiraju¹, Arunmozhimaran Elavarasi², Nishkarsh Gupta³, Rohit Kumar Garg⁴, Saurav Sekhar Paul⁴, Saurabh Vig³, Prashant Sirohiya³, Brajesh Ratre³, Rakesh Garg³, Anuja Pandit³, Ram Singh³, Balbir Kumar³, Ved Prakash Meena⁴, Naveet Wig⁴, Saurabh Mittal⁵, Sourabh Pahuja⁵, Karan Madan⁵, Nupur Das⁶, Tanima Dwivedi⁶, Ritu Gupta⁶, LaxmiTej Wundavalli⁷, Angel Rajan Singh⁷, Sheetal Singh⁷, Abhinav Mishra³, Manisha Pandey³, Karanvir Singh Matharoo³, Sunil Kumar⁸, Anant Mohan⁵, Randeep Guleria⁵, Sushma Bhatnagar⁴

Affiliations

¹ Department of Preventive Oncology, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
² Department of Neurology, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
³ Department of Onco-Anesthesia and Palliative Medicine, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
⁴ Department of Medicine, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
⁵ Pulmonary Medicine, Critical Care and Sleep Disorders, All India Institute of Medical Sciences, New Delhi, India.
⁶ Department of Laboratory Oncology, All India Institute of Medical Sciences, New Delhi, India.
⁷ Department of Hospital Administration, All India Institute of Medical Sciences, New Delhi, India.
⁸ Department of Surgical Oncology, All India Institute of Medical Sciences, New Delhi, India.

Abstract

Background: While long-term studies on the correlates of protection, vaccine effectiveness, and enhanced surveillance are awaited for SARS-CoV-2 vaccine, studies on breakthrough infections help understand the nature and course of this illness among vaccinated individuals and guide in public health preparedness. This study aims to compare the differences in the hospitalization outcomes SARS-CoV-2 infection of fully vaccinated individuals with with those of unvaccinated and partially vaccinated individuals.

Materials and methods: Single institution observational cohort study. This study compared the differences in clinical, biochemical parameters and the hospitalization outcomes of 53 fully vaccinated individuals with those of unvaccinated (1464) and partially vaccinated (231) individuals, among a cohort of 2,080 individuals hospitalized with SARS-CoV-2 infection. Descriptive statistics and propensity-score weighted multivariate logistic regression analysis adjusting for clinical and laboratory parameters were used to compare the differences and to identify factors associated with outcomes.

Results: Completing the course of vaccination protected individuals from developing severe COVID-19 as evidenced by lower proportions of those with hypoxia, abnormal levels of inflammatory markers, requiring ventilatory support, and death compared to unvaccinated and partially vaccinated individuals. There were no differences in these outcomes among patients who received either vaccine type approved in India.

Conclusions: Efforts should be made to improve the vaccination rates as a timely measure to prepare for the upcoming waves of this highly transmissible pandemic. Vaccination rates of the communities may also guide in the planning of the health needs and appropriate use of medical resources.

Keywords: Breakthrough infection; SARS-CoV-2 vaccine; mortality; severe illness.