Worldwide demand for Pfizer Inc's oral Covid-19 antiviral treatment Paxlovid has been unexpectedly light due to complicated eligibility requirements, reduced testing, and potential for drug interactions, a Reuters review of data and interviews with experts has found.

Demand also has been hampered by the perception that Omicron infections are not that severe.

Paxlovid was expected to be a major tool in the fight against Covid-19 after it reduced hospitalisations or deaths in high-risk patients by around 90 percent in a clinical trial.

Thousands of people still die from Covid-19 every week, even as...