Covid-19 Vaccination and Case fatality rate in India

Abstract

The disease COVID-19 entered India in January 2020 and since then has spread substantially within the country. Till date India has experienced two severe wave of COVID-19 infection. In the absence of any effective therapeutics or drugs, emerging variants of the virus and with an unknown epidemiological life cycle, lockdown and restrictions at public places slowed down the spread of novel corona virus in the country [1].  However, a high number of new COVID-19 cases and deaths due to it are reported across the country. In India, vaccine against corona virus was initiated in January 2021 to elderly and individuals with chronic disease to control the spread and severity of the disease. It is anticipated that the third wave of COVID-19 will emerge in India in near future. The government has increased the vaccination rate and seeks to achieve higher coverage as early as possible to avoid a severe outcome in the third wave. Therefore, in this paper, we aimed to assess the effectiveness of vaccination in controlling the severity of the disease (case fatality rate) in Indian population and six selected states.

Corona virus disease (COVID-19) was declared a pandemic by the World Health Organization (WHO) on 11^th March, 2020 [2]. In India, the first confirmed case of COVID-19 was reported from Kerala on 30^th January 2020. There was a rapid increase in the number of positive cases thereafter and the first mortality due to COVID-19 was reported on 12^th March 2020 from Karnataka, India [3-4].  As of August 06^th 2021, more than 31.8 million confirmed cases of Covid-19 were reported in India, the second highest number of cases by any other country after United States of America [5]. Maharashtra, Kerala and Karnataka are the hot spots for COVID-19 infection. The number of deaths due to COVID-19 had surpassed 0.42 million in the country and the maximum mortality is reported from Maharashtra [5]

India being the second most populated country in the world has faced a challenge in controlling the spread of the infection. During the first wave of COVID-19, the main challenges were acute shortage of beds, medicine and ventilators, lesser trained healthcare workforce, scarcity of Personal Protective Equipments (PPE) and unvaccinated healthcare workers [6]. Indian Council of Medical Research and the Ministry of AYUSH (Ayurveda, Yoga and Naturopathy, Unani, Siddha, and Homeopathy) recommended the use conventional preventive and treatment strategies to improve individual’s immunity against COVID-19 and to lower the severity of viral infection [7]. During the second wave of COVID-19, the main challenges were shortage of beds with ventilators and limited oxygen supply [8].There are a number of barriers prevalent in the country that hinders the achievement of high vaccination rate like illiteracy, access to healthcare services, belief in traditional medicines and myths associated with vaccine.

We carried out a study to evaluate the effectiveness of vaccination in India to control the severity of COVID-19 from 21^st March 2020 to 6^th August 2021 (total 72 weeks). The data was collected from the dashboard on the website of Ministry of Health, India, covid19india.org and cowin dashboard. In addition we randomly selected six states of India to include in the analysis.

We divided the period of 72 weeks into pre-vaccination and post-vaccination phase. We analyzed the data of COVID-19 phase wise at national level and for 6 states of India. We calculated case fatality rate (CFR) by using the formula “total mortality due to COVID-19 in a given period divided by total confirmed cases” in that duration. The vaccination coverage was calculated by using the formula “cumulative frequency of vaccine dose given to the people in that duration divided by approximate population above 18 years”.

In the time period of this study, March 21^st 2020 to 6^th August 2021, a total of 72 weeks of COVID-19 infection has completed in the country. In India, first dose of vaccination started in 44^th week after the emergence of COVID-19 infection and second dose was initiated from 48^th week. At the country level the highest CFR was 17.3% during pre-vaccination phase in 12-16 weeks and in post-vaccination phase the highest CFR was 21.0% in 64-68 weeks. The increased CFR post-vaccination may be due to the low coverage of vaccination as the country had first dose coverage of 300/1000 population and second dose coverage of 73/1000 population by 68 weeks.

As on 6^th August 2021, the 1^st dose coverage of COVID-19 vaccine in India was 388/1000 population and 2^nd dose coverage was 115/1000 population. Among the 6 states studied, 3 states [New Delhi-1^st dose (668/1000 population) and 2^nd dose (250/1000 population); Karnataka-1^st dose (554/1000 population) and 2^nd dose (157/1000 population); and Telangana-1^st dose (449/1000 population) and 2^nd dose (147/1000 population)] had higher vaccine coverage than at the national level.

Telangana showed better vaccination coverage with low severity compared to other states, while New Delhi showed a decline in the case fatality rate after the first and second dose coverage of vaccination increased by two times. Thus, vaccination for COVID-19 infection is found to be effective in decreasing the severity of the disease. The eligible population should avail the services provided at the government facilities free of cost to reduce the disease burden of severe cases being admitted to health facilities.