Prophylactic role of ivermectin in SARS-CoV-2 infection among healthcare workers

Background: Healthcare workers (HCWs) are vulnerable to getting infected withSARS-CoV-2. Preventing HCWs from getting infected is a priority to maintain healthcare services. The therapeutic and preventive role of ivermectin in COVID-19 is being investigated. Based on promising results of in vitro studies of oral ivermectin, this study was conducted with the aim to demonstrate the prophylactic role of oral ivermectin in preventing SARS-CoV-2 infectionamong HCWs at All India Institute of Medical Sciences (AIIMS), Bhubaneswar. Methods: A prospective cohort study was conducted at AIIMS Bhubaneswar, which provides both COVID and Non-COVID care since March 2020. All employees and students of the institute who provided written informed consent participated in the study.Uptake of two-doses of oral ivermectin (300 μg/kg at a gap of 72 hours) was considered as exposure. The primary outcome of the study was COVID-19 infection in the following month of ivermectin consumption diagnosed by RTPCR as per Government of India testing criteria guidelines.The log-binomial model was used to estimate adjusted relative risk, and the Kaplan-Meier failure plot was used to estimate the probability of COVID-19 infection with follow-up time. Results: Of 3892 employees, 3532 (90.8%) participated in the study. The ivermectin uptake was 62.5% and 5.3% for two-doses and single-dose, respectively. Participants who took ivermectin prophylaxis had a lower risk of getting symptoms suggestive of SARS-CoV-2 infection(6% vs 15%). HCWs who had taken two-doses of oral ivermectin have a significantly lower risk of contracting COVID-19 disease during the following month (ARR 0.17; 95% CI, 0.12-0.23). Females had a lower risk of contracting COVID-19 than males (ARR 0.70 95% CI, 0.52-0.93). The absolute risk reduction of SARS-CoV-2 infection was 9.7%. Only 1.8% of the participants reported adverse events, which were mild and self-limiting. Conclusion: and relevance Two-doses of oral ivermectin (300 μg/kg given 72 hours apart) as chemoprophylaxis among HCWs reduces the risk of COVID-19 infection by 83% in the following month. Safe, effective, and low-cost chemoprophylaxis have relevance in the containment of pandemic alongside vaccine.