The US firm developed antiviral COVID 19 pills, which are the next step in the pandemic battle.
Some countries have raised concerns that shortages and manufacturing chaos could hamper global supply, according to The Washington Post.
Wealthy countries have already advance-purchased many of the treatments expected to be available in the first half of 2022.
The pills involved are Pfizer s Paxlovid and Merck's Molnupiravir, co-developed with Ridgeback Biotherapeutics and Emory University.
A World Health Organization report earlier this month warned of the high risk of shortages of Paxlovid for low and middle-income countries until generic versions are more widely available, which is likely to be the second half of 2022, according to the Post.
Pfizer and Merck have reached an agreement to share the license for the drugs making generic versions available in India and Bangladesh.
Although vaccines help to build immunity before infection, antiviral treatments such as Paxlovid and molnupiravir are used soon after symptoms appear.
Pfizer and Merck have shared the licenses for their drugs with the United Nations-backed Medicine Patent Pool, a nonprofit that aims to improve access to medicines, as well as with specific producers.
Under the agreement, each company would allow generic versions of the drugs to cover more than half of the world's population, with Pfizer and Merck retaining market control for high-income and upper-middle-income countries.
The drugsmakers will need time to draw up manufacturing plans, with treatments still need regulatory approval.