A report published online on Research Square ahead of peer review by the University of California, San Francisco (UCSF) researchers stated that the use of Pfizer Inc′s oral antiviral drug Paxlovid needs additional clinical evidence.

Three recent case studies revealed that patients with COVID-19 infections suffered long-term symptoms. The three patients, all in their 40s and previously vaccinated against COVID-19 were all enrolled in the UCSF LIINC long COVID study. Two patients who received Paxlovid antiviral medication reported significant improvement in their long-term COVID symptoms.  The third patient was administered the drug as directed to treat an acute infection. His symptoms subsided at first but reoccured quickly after he stopped using the medication, and he later acquired long COVID.

Long COVID is thought to affect up to 30% of persons infected with the coronavirus and can last for months, with symptoms including weariness, fast heartbeat, shortness of breath, chronic pain, mental fog, and muscle weakness. It affects both mild and severe COVID-19 patients, including youngsters, and can be severe enough to keep people out of work.

Researchers expressed hope that the drug would be effective as an early antiviral therapy and would also aid in the prevention of severe and long COVID. However, the third case study, tells a different story. 

The findings aren′t conclusive, but they do provide insight into long COVID, a poorly known syndrome that leaves researchers searching for answers. Hence, antiviral medicines, like Paxlovid, required more detailed and large-scale trials. (Reuters, May 6, 2022)