Incidence and severity of COVID-19 infection post-vaccination: a survey among Indian doctors

Abstract

Purpose The rollout of COVID-19 vaccines began in India in January 2021, with healthcare professionals being the first to receive vaccination. The purpose of this research was to study the incidence and severity of COVID-19 infections among Indian doctors, following vaccination with ChAdOx1 nCoV-19 or BBV152. Methods We conducted an online voluntary survey among Indian doctors who received one or two doses of ChAdOx1 nCoV-19 or BBV152. Questions pertaining to the incidence and severity of COVID-19 infection following vaccination were asked. Data thus obtained were analysed. Results 9146 doctors were included in this study. 8301 of these received ChAdOx1 nCoV-19, while 845 received BBV152. 2842 (31.07%) respondents reported having a COVID-19 infection following vaccination. Presence of pre-existing medical comorbidities was associated with a higher incidence, while prior COVID-19 infection and two doses of either vaccine were associated with a lower incidence of COVID-19 infection post-vaccination. Exposure to COVID-19 patients on a daily basis did not increase the incidence of COVID-19 infection among doctors who were vaccinated. Increasing age, male gender, presence of pre-existing medical comorbidities, and daily exposure to COVID-19 patients were associated with increased severity of COVID-19 infection after vaccination. Two doses of either vaccine resulted in less severity of disease compared to one dose. Conclusion ChAdOx1 nCoV-19 and BBV152 confer immunity against severe forms of COVID-19 infections. COVID-19 infections prior to vaccination result in a lower incidence of breakthrough infection. Presence of pre-existing medical comorbidities is associated with increased incidence and severity of breakthrough infections.

Incidence and severity of COVID-19 infection among health care workers following vaccination: a cross sectional survey in Maharashtra

“…In the study, male participants were more infected with COVID-19 than females and even males had acquired more COVID-19 infection following vaccination when compared to female participants. These findings were in concurrence with the findings of the study conducted by Parmeshwaran et al 8 In the present study, vaccinated participants with preexisting illnesses reported greater incidence of COVID-19 infection following vaccination and also the participants with recommended complete doses had a significantly lesser rate of COVID-19 infection post vaccination compared to those with partial doses of the respective vaccine. These results were similar to the study of Parmeshwaran et al 8 The present study also revealed reduced incidence (p<0.05) of COVID-19 infection post vaccination among participants who had history of past COVID-19 infection before the receipt of vaccine.…”

Inactivated vaccine Covaxin/BBV152: A systematic review

“…In participants with prior viral exposure, two doses of BBV152 accorded sufficient protection, with an 87% efficiency against symptomatic reinfection, while a single dose was only 16% effective ( 43 ). A questionnaire-based study of health-care workers reported significantly reduced incidence and severity of COVID-19 infection in those receiving two doses of both Covaxin and Covishield compared to a single dose of either vaccine ( 44 ). Kumar et al.…”

Risk factors for SARS-CoV-2 infection after primary vaccination with ChAdOx1 nCoV-19 or BNT1262b2 and after booster vaccination with BNT1262b2 or mRNA-1273: a population-based cohort study (COVIDENCE UK)

“…While much research has been done on risk factors for SARS-CoV-2 infection in unvaccinated populations, risk factors for breakthrough infection in vaccinated individuals are less well understood and existing studies present conflicting findings. Whereas some studies have reported a higher risk of breakthrough infection among individuals with comorbidities, 9,10 other large-scale studies have found no associations with pre-existing conditions. 2 Similarly, several studies have suggested that older age is associated with increased risk of breakthrough infections, 11,12 whereas others have found no association 13,14 or an inverse association.…”

“…2 Similarly, several studies have suggested that older age is associated with increased risk of breakthrough infections, 11,12 whereas others have found no association 13,14 or an inverse association. 2 Most studies on risk of breakthrough infection have been limited to specific subgroups, 10,13,15 focused solely on severe outcomes, 16,17 or only considered infections before a booster dose. 2,9 Additionally, the few studies considering behaviours, such as levels of physical activity or journeys on public transport, have relied on baseline values, 2 and so have been unable to capture changes in behaviour that may have occurred over the various stages of the pandemic.…”