Shipping a coronavirus vaccine around the world will be the "largest transport challenge ever" according to the airline industry.
The equivalent of 8,000 Boeing 747s will be needed, the International Air Transport Association (IATA) has said.
There is no Covid-19 vaccine yet, but IATA is already working with airlines, airports, global health bodies and drug firms on a global airlift plan.
The distribution programme assumes only one dose person is needed.
"Safely delivering Covid-19 vaccines will be the mission of the century for the global air cargo industry. But it won't happen without careful advance planning. And the time for that is now," said IATA's chief executive Alexandre de Juniac.
