The UN health agency Friday "strongly recommended" the use of nirmatrelvir and ritonavir, sold under the name Paxlovid, for mild and moderate Covid patients at the highest risk of hospital admission. The oral antiretroviral drug was developed by Pfizer and is "the best therapeutic choice for high-risk patients to date," the World Health Organization (WHO) said. The recommendation is based on new data from two randomised controlled trials involving more than 3,000 patients that found an 85 percent reduction in the risk of hospitalisation. Read: WHO says global COVID cases, deaths declined again last week However, the WHO said availability, lack of price transparency in bilateral deals made by the producer, and the need for prompt and accurate testing before administering it are turning this life-saving medicine into a major challenge for low- and middle-income countries. One obstacle for low- and middle-income countries is that the medicine can only be administered while the disease is at its early stages, making prompt and accurate testing essential for successful outcomes.