The pill shows a 30% reduction in hospitalisations and deaths based on data from over 1,400 patients, compared to about 50% in October based on data from 775 patients.
Pfizer will sub-licence production of its Paxlovid pill to generic drug manufacturers for supply in 95 low- and middle-income nations covering around 53% of the world's population.
The trials conducted on 90 people located in home-like conditions with someone who has symptomatic Covid-19 began on Nov 12 and will continue until March 2023.
Doctors warn vaccine hesitant people not to confuse the benefit of the treatments with prevention afforded by vaccines.
Both drugs are being studied to see if they can prevent infection in people exposed to the virus.
Health Minister Khairy Jamaluddin says the treatment pills are necessary in addition to the vaccination programme.