A comparison of clinical outcomes between vaccinated and vaccine-naive patients of COVID-19, in four tertiary care hospitals of Kerala, South India

Sabarish Balachandran; Merlin Moni; Dipu T Sathyapalan; Prinoj Varghese; Manoj P Jose; Mithun R Murugan; C Rajan; Dhanraj Saboo; Sooraj S Nair; Reshmi Ann Varkey; Parvathy Balachandran; Geetha R Menon; Beena K Vasudevan; Amitava Banerjee; Chandrasekhar Janakiram; Jaideep C Menon

doi:10.1016/j.cegh.2022.100971

A comparison of clinical outcomes between vaccinated and vaccine-naive patients of COVID-19, in four tertiary care hospitals of Kerala, South India

Clin Epidemiol Glob Health. 2022 Jan-Feb:13:100971. doi: 10.1016/j.cegh.2022.100971. Epub 2022 Jan 19.

Authors

Sabarish Balachandran¹, Merlin Moni², Dipu T Sathyapalan², Prinoj Varghese³, Manoj P Jose⁴, Mithun R Murugan⁵, C Rajan³, Dhanraj Saboo⁶, Sooraj S Nair⁷, Reshmi Ann Varkey⁸, Parvathy Balachandran⁹, Geetha R Menon¹⁰, Beena K Vasudevan⁸, Amitava Banerjee¹¹, Chandrasekhar Janakiram⁹, Jaideep C Menon¹²

Affiliations

¹ Department of Emergency Medicine, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, 682041, India.
² Division of Infectious Diseases, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, 682041, India.
³ Department of General Medicine, Sree Narayana Institute of Medical Sciences, Kerala, 683594, India.
⁴ Department of General Medicine, Little Flower Hospital and Research Centre, Kerala, 683572, India.
⁵ Internal Medicine, PRS Hospital, Thiruvananthapuram, Kerala, 695002, India.
⁶ Department of Medicine, Little Flower Hospital and Research Centre, Kerala, India.
⁷ PRS Hospital, Killipalam, Thiruvananthapuram, Kerala, 695002, India.
⁸ Department of Public Health, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, 682041, India.
⁹ Amrita School of Dentistry, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, 682041, India.
¹⁰ ICMR- National Institute of Medical Statistics, New Delhi, India.
¹¹ Professor in Clinical Data Science and Honorary Consultant Cardiologist, Institute of Health Informatics, University College London, United Kingdom.
¹² Preventive Cardiology Unit, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, 682041, India.

Abstract

The problem considered: This multi-centric study analyzed data of COVID-19 patients and compared differences in symptomatology, management, and outcomes between vaccinated and vaccine-naive patients.

Methods: All COVID-19 positive individuals treated as an in-or out-patient from the 1^stMarch to 15^th May 2021 in four selected study sites were considered for the study. Treatment details, symptoms, and clinical course were obtained from hospital records. Chi-square was used to test the association of socio-demographic and treatment variables with the vaccination status and binary logistic regression were used to obtain the odds ratio with a 95% confidence interval.

Results: The analysis was of 1446 patients after exclusion of 156 with missing data of which males were 57.3% and females 42.7%. 346 were vaccinated; 189 received one dose and 157 both doses. Hospitalization was more in vaccinated (38.2% vs 27.4%); ICU admissions were less in vaccinated (3.5% vs 7.1%). More vaccinated were symptomatic (OR = 1.5); half less likely to be on non-invasive ventilation (OR = 0.5) while vaccine naive patients had 4.21 times the risk of death.

Conclusion: Severe infection, duration of hospital stays, need for ventilation and death were significantly less among vaccinated when compared with vaccine naive patients.

Keywords: COVID-19; Coronavirus; Outcomes; Vaccine; Vaccine-breakthrough infection.