Monday's potential breakthrough in the race to develop a COVID-19 vaccine has left governments scrambling to meet the logistical challenge of distributing hundreds of millions of doses once it becomes available in coming months. Interim trial data showed the experimental vaccine developed by Pfizer Inc and Germany's BioNTech was 90% effective, spurring hopes of an end to a pandemic that has cost more than a million lives and crashed the world's major economies. With the two groups expecting to produce some 50 million doses by the end of the year and 1.3 billion doses next year, assuming regulatory approval, German Health Minister Jens Spahn, said the vaccine was a "light at the end of the tunnel". Both the United States and the European Union have agreements to secure hundreds of millions of doses of the drug, but authorities will need sophisticated planning and logistics to ensure they are distributed effectively. BioNTech said it was planning to price the two-shot regimen below "typical market rates" and would differentiate pricing between countries or regions. But the vaccine must be shipped and centrally stored at minus 70 degrees Celsius, putting it out of reach for the moment of many poor countries in Asia and elsewhere which lack the necessary refrigeration equipment. Needing temperatures matching an Antarctic winter, it is likely to need centralized vaccination locations, Swiss health experts said on Tuesday. "The exciting news yesterday (Monday) of a possible effective vaccine becoming available presages significant cold chains challenges for African countries by the type of vaccine that that is," Matshidiso Moeti, the World Health Organization's regional director for Africa, told a ministerial assembly. "Which will need to be factored into the support to be provided." Thermal boxes would preserve the ultra-low temperatures for up to 10 days for ambient temperatures of up to 25 Celsius without opening them and up to 15 days if the boxes are opened and then re-iced, BioNTech said in presentation slides. As previously announced, the vaccine can be kept for up to five days at fridge temperatures. Too many unknowns U.S. Health Secretary Alex Azar said on Tuesday the United States, which has a $2 billion contract for 100 million doses of the Pfizer vaccine, could receive 20 million doses per month starting at the end of this month if Pfizer moves as quickly as expected to secure regulatory approval. For its part, the European Commission, which is negotiating with vaccine makers on behalf of EU states, is expected to sign off on a deal on Wednesday to secure 300 million doses of the vaccine. Britain, which expects to have 10 million doses of the vaccine available by the end of the year, asked the National Health Service to be ready to deploy any COVID vaccine from the start of December. European logistics specialists said they were capable of meeting the challenge of ultra-cold storage. "Distribution will not fail because of logistics," Frank Appel, chief executive of Germany's Deutsche Post, told journalists. The group said it was already talking to pharmaceutical companies and governments on the details, including the need for cooling. Deutsche Post said its contract logistics division operates in more than 180 locations worldwide, tailored to the needs of the pharmaceutical industry, where sensitive medical products can be stored and packaged at different temperatures. With Germany expecting to receive 100 million doses of the vaccine, authorities in Berlin also expect to draw on the military to help manage storage. A government source in Italy said the army was also likely to be called on to help manage storage and distribution. —Emma Thomasson Source