ABSTRACT
COVID-19, an infectious disease, has become a leading cause of death in many people. The rapid emergence of the pandemic prompted the development of a vaccine to mitigate the disease's harmful consequences. Vaccination is the only effective way to prevent infection from spreading and build immunity to the virus. However, developing adverse effects has become a major problem for vaccine reluctance. Accordingly, the interest has been shifted towards identifying the adverse effects developed following immunization. The current study objective is to assess and compare the intensity of adverse effects following 1st and 2nd dose of COVID-19 vaccination and the medication administered to relieve the symptoms associated with vaccination. A cross-sectional study was performed in a community over six months. A total of 836 participants were involved in the study. All the data regarding the vaccination were collected through a specially designed questionnaire form and analyzed in all the participants within the study group. According to the study, at least 1 AEFI was developed in about 90% of the study population. The most common systemic and local effect developed in the study population was fever (59.42%) and pain at the injection site (69.82%), respectively. With both vaccines (ChAdOx1 nCoV-19 and BBV152), the incidence and severity of AEFIs were lower after the second dose than after the first dose, and most of the symptoms associated with vaccination were alleviated by taking home remedies and symptomatic treatment. The adverse effects reported after receiving the ChAdOx1 nCoV-19 and BBV152 vaccines are typical of most vaccines, and the majority of them were tolerated, and most subsided in less than 24 hours.
ABSTRACT
OBJECTIVES: India introduced BBV152/Covaxin and AZD1222/Covishield vaccines in January 2021. We estimated the effectiveness of these vaccines against severe COVID-19 among individuals aged ≥45 years. METHODS: We did a multi-centric, hospital-based, case-control study between May and July 2021. Cases were severe COVID-19 patients, and controls were COVID-19 negative individuals from 11 hospitals. Vaccine effectiveness (VE) was estimated for complete (2 doses ≥ 14 days) and partial (1 dose ≥ 21 days) vaccination; interval between two vaccine doses and vaccination against the Delta variant. We used the random effects logistic regression model to calculate the adjusted odds ratios (aOR) with a 95% confidence interval (CI) after adjusting for relevant known confounders. RESULTS: We enrolled 1143 cases and 2541 control patients. The VE of complete vaccination was 85% (95% CI: 79-89%) with AZD1222/Covishield and 71% (95% CI: 57-81%) with BBV152/Covaxin. The VE was highest for 6-8 weeks between two doses of AZD1222/Covishield (94%, 95% CI: 86-97%) and BBV152/Covaxin (93%, 95% CI: 34-99%). The VE estimates were similar against the Delta strain and sub-lineages. CONCLUSION: BBV152/Covaxin and AZD1222/Covishield were effective against severe COVID-19 among the Indian population during the period of dominance of the highly transmissible Delta variant in the second wave of the pandemic. An escalation of two-dose coverage with COVID-19 vaccines is critical to reduce severe COVID-19 and further mitigate the pandemic in the country.