Figures for the doses of Covid-19 vaccines being allocated mainly to 92 low- and middle-income countries by June from the international COVAX scheme will be published on Wednesday, agencies said.
In all 190 countries have joined COVAX, launched last April with the goal of ensuring equitable access to vaccines during the pandemic.
The GAVI alliance, World Health Organization, Coalition for Epidemic Preparedness Innovations and the U.N. Children's Fund will publish its "interim distribution forecast" at 1300 GMT, GAVI said.
GAVI CEO Seth Berkley said last week that COVAX aimed to deliver 2.3 billion doses by year-end, including 1.8 billion to lower income countries at no cost to their governments.
UNICEF, the largest single buyer of vaccines in the world, expects a "crush" of demand in the first half of the year, with supplies only loosening in the second, its executive director Henrietta Fore said on Friday.
A vaccine crisis has flared in some areas, coming to a head with export controls announced by the European Union which followed news that AstraZeneca would cut its supply of doses to the bloc until March due to production problems.