PfizerThe oral course will be available in up to 4,000,000 units Covid-19The company revealed Tuesday that it had reached an agreement with United Nations Children’s Fund to provide treatment for dozens of countries in need.

Pfizer will start supplying Paxlovid antiviral tablets to UNICEF next month. The company expects that it will do this until the end. According to Pfizer, the tablets will be provided at no cost for low-income countries, and higher-income ones will have to pay more due to a tiered pricing structure.

CNBC asked Pfizer for financial details of the deal.

Pfizer licensed Paxlovid via the Medicines Patent Pool. This U.N.-backed organization will enable other companies to create a generic version of Covid to increase supply in low-income countries around the globe. So far 35 companies in 12 nationsLatin America, South America, and South Asia signed deals to produce either raw ingredients or finished drug products.

UNICEF and Paxlovid will be supplied to those 95 countries with low or middle incomes. Pfizer stated that the aim of this agreement was to give short-term access the oral antiviral therapy while companies set up generic manufacturing.

In December, the U.S. Food and Drug Administration approved Paxlovid for use on an urgent basis by people aged 12 and over. Clinical trials showed that Paxlovid prevented hospitalization for those who were at highest risk of serious Covid.

Based on agreements already concluded or nearing completion, Pfizer anticipates Paxlovid sales of $22 billion by 2022. Up to 20 million Paxlovid prescriptions will be delivered to the U.S. by this drugmaker through September 2017.

Paxlovid should be administered immediately after the Covid-19 diagnosis. It is administered in three tablets twice daily over five days. Pfizer developed two tablets of nirmatrelvir and one tablet each of ritonavir. Both drugs are widely used in HIV treatment. Nirmatrelvir stops the replication of the virus’ enzyme, while Ritonavir slows patients’ metabolism and allows the drug to stay active longer.

Pfizer has licensed Paxlovid widely for generic production, but not the Covid vaccine. Oxfam America called upon shareholders attending the annual meeting to help fund a feasibility report on the transfer of technology that underpins the vaccine into developing countries.

The board of Pfizer has asked shareholders to reject the proposal. They argue that vaccine technology is complicated and needs high-level expertise to ensure the highest quality shots. Pfizer plans to provide 2 billion doses of vaccines to the poorer countries by 2022.