Pfizer Inc. /zigman2/quotes/202877789/composite PFE -0.63% said Tuesday it has signed a voluntary license agreement with United Nations-backed public health organization the Medicines Patent Pool that will allow generics makers to manufacture its COVID-19 oral antiviral treatment. The move will help expand access to the drug to low and middle-income countries. Under the terms of the main license agreement, qualified generic medicine manufacturers worldwide that are granted sub-licenses "will be able to supply PF-07321332 in combination with ritonavir to 95 countries, covering up to approximately 53% of the world's population," the company said in a statement. "This includes all low- and lower-middle-income countries and some upper-middle-income countries in Sub-Saharan Africa as well as countries that have transitioned from lower-middle to upper-middle-income status in the past five years. " Pfizer will not receive royalties on sales in those countries and will also waive royalties on sales in all countries covered by the agreement as long as COVID remains classified as a Public Health Emergency of International Concern by the World Health Organization. Pfizer said last week it would seek an emergency-use authorization for the treatment "as soon as possible." The company released data from a double-blind Phase 2/3 clinical trial in 1,219 unvaccinated adults with COVID-19 who were at high risk of severe disease and found it reduced the risk of dying or ending up in the hospital by 89%. Less than 1% of the patients who took the drug were hospitalized by the 28-day mark, compared with the 7% who received the placebo and were hospitalized or died. Participants took two pills a day for five days. Antivirals are expected to become a game changer in the pandemic, as they can be taken at home, while the current treatments are done by infusion in a clinical setting. Pfizer shares were down 0.7% premarket but have gained 35% in the year to date, while the Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA -0.38% has gained 18% and the S&P 500 /zigman2/quotes/210599714/realtime SPX -1.04% has gained 25%.