Vaccination and COVID-19 positivity rates in a network of eye hospitals in Southern and Eastern India during the second wave of COVID-19.

Dear Editor, In India, the first case of coronavirus disease 2019 (COVID-19) was reported on January 30, 2020, following which it spread across the entire country and slowed down by the end of 2020. Subsequently, India experienced a second wave from March to June 2021, which was more devastating than the first wave. As the pandemic worsened, a mass vaccination program was rolled out by the Central Government in India on January 19, 2021. In the first round, health-care workers (HCWs), designated as a priority group, were vaccinated across the country. Since there was no vaccine that was 100% effective, despite having obtained their vaccines, HCWs remained vulnerable to infection. In this report, we examine the relationship between vaccination, COVID-19 positive rates, and risk factors in the context of the COVID-19 second wave in a network of eye care hospitals in southern and eastern India. The study setting consisted of one Centre of Excellence (CoE), three different tertiary centres (TCs – TC1, TC2, TC3), a network of secondary centres (SCs) in four states (Andhra Pradesh, Telangana, Odisha, and Karnataka), along with a rural network of primary care vision centres (VCs) surrounding these SCs in these four states. Apart from these, another administrative campus and training centre located in the state of Telangana was also part of this study. For all the staff, data were collected in terms of their age, gender, type of employment (outsourced/full-time), working area (clinical/non-clinical), type of transport used to commute to workplace (public/private), type of family (single/nuclear/joint), and type of housing (individual home/apartment/hostel). Details of vaccination status (including the type – Covishield or Covaxin) were collected, as well as the reasons for not getting vaccinated. Testing strategy across the network included testing all symptomatic HCWs or high-risk contacts of COVID-19–positive patients, either in-house (TC3) or outsourced to accredited laboratories (all others). Data were analyzed using STATA (version 16) software (Stata Corp, College Station, TX, USA). Data between March and June 2021 were available for 2864 employees. The mean age was 32.03 years (standard deviation [SD]: 9.8 years). There were 1376 males (48.04%). Campus wise distribution of employees was as follows: CoE- 1262, TC1- 266, TC2- 156, TC3- 289, SC- 621, VC- 225, and other campus- 45. Clinical staff numbered 1771 (61.8%). Outsourced employees numbered 302 (10.5%). Also, 2141 (75.6%) were having their own transport. Type of family was as follows: single- 191 (6.7%), nuclear- 1986 (69.4%), and joint- 684 (23.9%). In terms of housing, 1648 (59.7%) employees had independent housing, 726 (26.3%) were staying in apartment, and 387 (14%) were staying in shared hostel accommodation. A total of 2382 (83.2%) staff were vaccinated, of whom 1741 (73.1%) have had Covishield vaccine and the remaining have had Covaxin. Two hundred and twenty-two (7.8%) staff members developed COVID-19 infection during this period. Among those vaccinated, 162 were positive (6.8%) and 144 (88.89%) were symptomatic. Among those who were unvaccinated, 60 were positive (12.5%) and all were symptomatic. Only three of 222 infected needed hospitalization, and all the three were from the unvaccinated group, of which one staff member died from the infection. Table 1 shows the univariate and multivariate analyses for risk factors for being COVID-19 positive. In univariate analysis, the risk factor for being COVID-19 positive was significantly higher in those at CoE, TC2, TC3, VC, and other campus, full-time employees, those staying in joint family and hostel, those staying in apartment, those not vaccinated, and those who have had Covaxin. In multivariate analysis, the odds of becoming COVID-19 positive were higher with increasing age, that is, with one unit increase, the odds increased by 2%. The odds were also higher in TC3 campus (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 1.15–8.39) and VCs (OR: 3.12, 95% CI: 1.42–6.83). The odds were also higher in those living in apartment (OR: 1.69, 95% CI: 1.14–2.5) and hostels (OR: 1.65, 95% CI: 1.0–2.76).Table 1: Univariate and multivariate logistic regression of the risk factors for becoming COVID-19 positiveDespite there being a high rate of infection in the second wave of the pandemic due to highly virulent strain, the COVID-19 vaccination program was reported to have significantly decreased hospitalizations and fatalities in many communities.[1-3] Different studies have found different positivity rates among HCWs after vaccination.[4] The difference in positivity rates between different studies could be due to the variability in the vaccination rates, types of vaccine used, testing strategy, as well as adherence to COVID-19 compliance behavior and exposure to the infection based on the type of health-care service in the unit. Our study also found that age was a significant risk factor for getting COVID-19 infection, increasing by 2% for every unit increase in age. COVID-19 showed a higher risk of serious illness and a lower possibility of recovery as people aged.[5,6] The cause could be age-related decline in immunity, decreased physiological function of vital organs, and underlying illnesses and they have all been associated with increased susceptibility to COVID-19.[7] Among the other risk factors, the risk of being COVID-19 positive was higher among the primary care VC staff as well as those in TC3 campus. We can speculate that the risk at VC seems to be higher due to the fact that the single technician staying in VC had to go out for multiple reasons (including having their meals), and also, the staff were not under close monitoring. Similarly, in TC3 campus, as there was in-house rapid testing facility, there was a tendency of higher testing, thus increasing the positivity rates. Risk was also higher for those staying in apartment and hostel for the obvious reason of overcrowding. Overcrowding in households significantly increases the risk of COVID-19.[8] In summary, this study is the first to forecast COVID-19 rates across an Indian network of eye hospitals. To protect the wellness of health-care professionals, especially adult health-care providers, all health-care professionals must undergo frequent and thorough training and continue taking vaccination booster doses. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.