Prespecified Homeopathic Medicines in the Prevention of Confirmed and Suspected Cases of COVID-19: A Community-Based, Double-Blind, Randomized, Placebo-Controlled Prophylaxis Trial

Introduction: Homeopathic medicines have been used for decades in the prevention and treatment of infectious diseases. However, the preventive efficacy of specific homeopathic medicines in COVID-19 is not well characterized. This study aimed to evaluate the comparative efficacy of prespecified homeopathic medicines in preventing COVID-19. Methods: A community-based, double-blind, randomized, placebo-controlled trial was conducted on 4,034 participants residing in Ward No. 27 of the Howrah Municipal Corporation in India. Participants were randomized to receive one of three prespecified homeopathic medicines [Influenzinum 30C, Arsenicum album 30C, Anas barbariae hepatis et cordis extractum 200K (Oscillococcinum (R))], or placebo. The outcomes were the incidence of laboratory-confirmed and suspected cases of COVID-19 during a follow-up period of 1 month. Results: During the follow-up period, a total of 13 new laboratory-confirmed COVID-19 cases were reported in the study population. Among these, 5 cases in Influenzinum group, 2 cases in Arsenicum album group, 1 case in Oscillococcinum (R) group, and 5 cases in Placebo group were reported. On the other hand, number of suspected COVID-19 cases was significantly less in all the three homeopathic medicine groups compared to placebo. The least number of suspected cases reported in the Oscillococcinum (R) group (aOR: 0.058; 95% confidence interval [CI]: 0.029, 0.114), followed by the Arsenicum album (aOR: 0.337; 95% CI: 0.238, 0.475) and Influenzinum (aOR: 0.539; 95% CI: 0.401, 0.726) groups. Conclusion: Prespecified homeopathic medicines, particularly Oscillococcinum (R) and Arsenicum album 30C, may have a role in preventing COVID-19, especially in reducing the incidence of suspected or COVID-19-like respiratory illnesses. However, the result failed to demonstrate a statistically significant difference in the occurrence of confirmed cases of COVID-19 between the study groups. Further research is needed to evaluate the efficacy of these medicines in different populations and settings.