Subtitles section Play video Print subtitles Pfizer and by on Tech have agreed to supply their cove in 19 shot to the World Health Organization's Kovacs Vaccine scheme, which is aimed at lower income countries. That's according to two sources familiar with the deal, who said it's expected to be announced on Friday. The scheme was set up last year as a result of concerns that poor nations would lose out as rich country scrambled to Secure Cove in 19 vaccines for their citizens. The Pfizer and by on tech vaccine would be Kovacs is second after AstraZeneca's details on the size of the deal or the price Kovacs would pay were not immediately clear. But the sources said the allotment of doses would likely be relatively small. One source says the limited doses air primarily meant for health care workers and Kovacs countries. The Pfizer shot is also more complicated to transport and store requiring ultra cold freezers, which may not be practical for poor countries with hot climates. Reuters reported Wednesday that the W H O plans to approve several more vaccines from Western and Chinese manufacturers in the coming weeks. In an updated forecast published on Thursday, Kovac said it planned to deliver nearly two billion doses to 92 countries this year, covering over a quarter of their populations. The Kovacs scheme is set to start distributing CO vid 19 vaccines next month. Ukraine said earlier on Thursday that its first delivery of some 210,000 doses under the Kovacs scheme could arrive in the first half of February.