The selective effect of Ivermectin on different human coronaviruses; in-vitro study

Background : The outbreak of coronavirus disease COVID-19, caused by Severe Acute Respiratory Coronavirus-2 (SARS-CoV-2) has become an urgent public health concern worldwide. Although several clinical trials have pointed to new drugs with some anti-COVID-19 activity, we are far from having a safe and effective drug. In this study, we tested the effect of ivermectin on several coronaviruses (serotypes), including variants of SARS-CoV-2. Methods : The effect of ivermectin was tested on cells infected with four different coronaviruses: NL63 (Alphacoronavirus genus.), OC43, SARS-CoV-2, and Omicron (all Betacoronavirus genus). Two hours post-infection, different doses of ivermectin were added to the cell culture. Results : There was no effect of even a high dose of ivermectin on NL63, however, we found a significant effect on OC43 PFU with a 40% inhibition at a dose of 5M. The impact of ivermectin on SARS-CoV-2 and on its Omicron variant was much more pronounced and at a dose of 5M there was inhibition of 90% and 95% respectively. Discussion : Although coronaviruses have been recognized as human pathogens for more than 50 years, no effective treatment strategy exists. Our current study did not demonstrate any effect of ivermectin on Alphacoronavirus but it had a specific impact on the Betacoronavirus genus with a mild impact on OC43 and a decidedly pronounced effect on SARS-CoV-2 including its Omicron variant. Ivermectin should be further studied as a single agent or as part of combined treatment against Coronaviruses.