Called molnupiravir the new drug is not as effective as Pfizer's recently approved COVID antiviral pill, and many experts suggest the FDA should never have authorized it in the first place as it has the potential to generate new SARS-CoV-2 variants.

Just a few months ago molnupiravir, being developed by pharma giant Merck, was being mooted as a game-changing new drug that could turn the tide of the pandemic. It was one of the first antiviral pills to directly target SARS-CoV-2, and a preliminary Phase 3 trial announcement indicated promising efficacy.

But as the weeks passed molnupiravir quickly lost its luster. Pfizer's novel antiviral pill raced to the head of the pack with impressive clinical trial data, while a final analysis of molnupiravir's Phase 3 data revealed a stark drop in efficacy, down to levels bordering on insignificant.

While Pfizer's final trial analysis reported up to 90 percent protection from COVID-19 hospitalization or death, molnupiravir's efficacy strangely dropped from interim analysis to final reporting. Initially Merck announced molnupiravir delivered around 50 percent protection from COVID-19 hospitalization or death but a final trial analysis weeks later revealed that efficacy had dropped to barely 30 percent.

Alongside the disappointing efficacy data, questions began to arise over the drug's safety profile, on both individual and societal levels.

Molnupiravir is a very different drug to Pfizer's COVID antiviral Paxlovid. Pfizer's drug is specifically targeted at SARS-CoV-2, working to inhibit the activity of a key enzyme the virus needs to replicate. Molnupiravir, on the other hand, targets RNA viruses in general. It was originally developed in 2018 as a tool to treat influenza, and lab work revealed it potentially worked against other RNA viruses including Ebola and the first SARS coronavirus.