(Bloomberg) -- More than two dozen generic-drug manufacturers have agreed to produce low-cost versions of Merck & Co.’s Covid-19 pill, a key step in bringing virus-fighting tools to lower-income countries that have struggled to get vaccines.

Companies in Bangladesh, China, India, Kenya, South Africa, Vietnam and other countries signed pacts to supply more than 100 low- and middle-income nations, the United Nations-backed Medicines Patent Pool said Thursday.

The effort to widen access to Covid drugs is advancing amid concerns that poorer nations could be left behind as they have been with vaccines. The latest development follows licensing accords announced late last year by Merck and Pfizer Inc., which is introducing another antiviral pill.

The manufacturers are working closely with regulatory authorities, and the expected treatments should be “rapidly available” in lower- and middle-income regions, said Charles Gore, the patent pool’s executive director. Yet as richer nations rush to purchase supplies, less affluent countries may have to wait until early 2023 for generic-drug companies to produce large quantities, London-based analytics firm Airfinity Ltd. estimated last month.

The patent pool said 27 generic-drug companies agreed to produce versions of the Merck antiviral, molnupiravir, developed with Ridgeback Biotherapeutics LP. Almost half will make both the raw ingredient and the finished drug.

Merck and its partners won’t receive royalties as long as Covid is classified as a public health emergency of international concern by the World Health Organization as part of the earlier agreement announced in October. The U.S. drugmaker said earlier this week it will supply the global relief organization Unicef with as many as 3 million treatment courses of molnupiravir.

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