The early days of Covid-19 attack was marked by total uncertainty, confusion and fear among the populace everywhere. Actually, the virus caught humanity unawares. Humans since the middle of 20th century had developed a kind of complacency that they are not as helpless as their ancestors were in the face of plague, small pox, cholera or suchlike epidemics. Medical science has been advancing at a breakneck pace since. Most known diseases are curable now. However, some types of cancers, dementia, especially Alzheimer's disease, have no cure. But medical science is familiar with such syndromes and some progress has been made in the research to fight them. But the SARS-CoV-2, or coronavirus, the virus behind COVID-19 disease-- the pandemic now raging across the globe, has been like an alien that was suddenly at humanity's doorstep. No vaccine was ready to immunize people against this alien virus. The complacency was gone and the world returned, as it were, to the bygone era when people would show a similar state of helplessness and confusion when nature visited any pestilence upon them.
So, the COVID-19 has been a great lesson for the scientists. And the outcome has been rewarding. Breaking all past records, they have developed prophylactic vaccines within the shortest possible time. After injectable vaccines, now is the time for pills to be taken orally at home. This opens up the scope for home treatment before hospitalisation, if needed. Pharmaceutical giants, Pfizer, Merck and partner Ridgeback Biotherapeutics and Roche Holding AG are at the forefront of researches to make oral anti-Covid-19 tablets. Each company has its own brand of pill under trial.
Pfizer, for example, has its drug, PF-07321332, in its late stage of trial. It is a drug to be used 12-hourly for five days. It belongs to the class of antiviral agents, the so-called protease inhibitors. Proteases are enzymes that play a crucial part in the coronavirus's replication mechanism in human body. As it is plain, the Pfizer drug PF-07321332, a protease inhibitor, prevents corona virus from reproducing. The pill is applied in combination with a low dose of another antiviral medication, ritonavir (used in HIV treatment). Ritonavir, the researchers believe, would slow down PF-07321332's metabolism thereby helping it to stay longer in body to effectively block the virus. The Pfizer drug is also being applied on high-risk patients with underlying conditions like diabetes. In its first trial conducted in July, the researchers tested the drug on people at high risk of becoming severe COVID-19 patients. The aim was to see if the drug can reduce hospitalisation and death. The second trial conducted in late August was to see the drug's efficacy on persons at low risk of getting severely ill with COVID-19. Here the aim was to see if the drug reduces the severity as well as the duration of the infection on the healthier, low risk patients.
The antiviral pill, Molnupiravir, made by Merck and partner Ridgeback Biotherapeutics, on the other hand, introduces error in the RNA of the of coronavirus thereby disabling its self-multiplication capacity. The drug, also in its very late stage of trial, is being tested on non-hospitalised adults in the same household showing symptoms of COVID-19 attack. The drug is in its Phase II/III trial. Once the detailed data are in hand, it would be possible to assess the drug's efficacy, especially on high-risk patients. The drug's rollout through emergency use authorisation (EUA) from drug regulator is awaiting the late-stage trial outcomes. The US government has promised US$1.2 billion to buy 1.7 million doses of Molnupiravir once the drug gets FDA approval. The drug made by Roche and partner Atea Pharmaceuticals (AVIR.O), AT-527, is claimed by the company to have reduced viral load on hospitalised patients.
The US government has earmarked US$3.2 billion to help develop antiviral drugs of this type that are in the R&D stage. The support to Merck and Ridgeback Biopharmaceuticals' Molnupiravir is part of this effort. It is believed the push would add further momentum to the world's war on the COVID-19 pandemic.