Molnupiravir dramatically reduces coronavirus replication and spread in ferrets. The virus is undetectable 24 hours after treatment with Molnupiravir.
Molnupiravir, or MK-4482/EIDD-2801, is a ribonucleoside analog of cytidine, a molecule with a basic formula similar to that of ribonucleoside analog (n4-hydroxycytidine) but with a modification that makes it not viable. This molecule induces errors in the replication of the genetic material of the virus through reverse transcriptase, thus preventing it from forming infectious virions. Therefore, it is a potentially effective broad-spectrum antiviral against all viruses with an RNA genome.
However, it has never been tested on SARS-Cov-2. For this reason, scientists at the University of Atlanta chose ferrets as an animal model to study the effect of Molnupiravir on virus transmission. They published their results in Nature. According to their study, the coronavirus is undetectable only 24 hours after treatment.
No detectable coronaviruses after 24 hours
Molnupiravir was given daily to the animals in tablet form through the feed 12 hours after they became infected with SARS-Cov-2. The scientists then observed that the treatment significantly reduced the excretion of the coronavirus in the first 12 hours after administration. The viral particles were undetectable, but the viral RNA was isolated from the animals’ noses 24 hours after treatment.
However ff the drug is administered during peak secretion, three days after inoculation of the virus in ferrets, a similar result is not observed until 36 hours after inoculation.
To study the effect of Molnupiravir on the spread of coronavirus, an infected ferret was placed in close contact with two other healthy animals for three days. The animals’ viral load was measured on the fourth day. The infected ferret, which was treated with Molnupiravir, did not transmit the coronavirus to his cagemates. His viral load was undetectable on the fourth day.
Molnupiravir is currently undergoing clinical trials sufficiently advanced to demonstrate its benefits against Covid-19 and its spread. They are funded by the pharma giant Merck in collaboration with Ridgeback Biotherapeutics, a start-up company that focuses on orphan and infectious diseases. The results of these clinical trials are expected by February 2021.