It will take one of the largest logistics operations in world history to deliver billions of doses of any new COVID-19 vaccine throughout the world and planning for this unprecedented operation has hardly begun.

Cargo aircraft will play the key role in getting these vaccines from where they're produced, mainly in developed countries, to all countries of the world, said the International Air Travel Association (IATA). This historic effort might require more than 8,000 cargo aircraft the size of the massive Boeing 747, estimates IATA. This number of aircraft, however, assumes the vaccine will be a one-dose drug. Of the four vaccines supported by U.S. funding in phase 3 clinical trials, only one is a one-dose vaccine.

"The potential size of the delivery is enormous," IATA pointed out Wednesday. "Just providing a single dose to 7.8 billion people would fill 8,000 (Boeing) 747 cargo aircraft."

The freighter version of the iconic Boeing 747 still remains one of the top cargo aircraft today. The Boeing 747 freighter versions are the Boeing 747-8F and the Boeing 747 LCF.

IATA called the upcoming deliveries of a COVID-19 vaccine or vaccines the "largest single transport challenge ever." This early, IATA asked governments to start preparing for the large-scale delivery of the vaccines by all modes of transport, especially air transport.

"Safely delivering COVID-19 vaccines will be the mission of the century for the global air cargo industry," said IATA CEO Alexandre de Juniac. "But it won't happen without careful advance planning. And the time for that is now."

IATA contends the delivery of these new vaccines requires careful planning with the air transport industry to avoid "potentially severe" issues when it's ready for global distribution. It urged governments to begin planning with "industry stakeholders" to ensure full preparedness when these vaccines become available for distribution.

IATA emphasized air cargo plays "a key role in the distribution of vaccines in normal times through well-established global time- and temperature-sensitive distribution systems." It said this capability will be crucial when it comes to transporting vaccines around the world.

Transporting vaccines never simple; they have to be handled and transported in accordance with international regulatory requirements. This means transporting vaccines at controlled temperatures and without delay to ensure the quality of the product.

IATA said while there are still many unknowns, such as the number of doses, temperature sensitivities and manufacturing locations, it's clear "the scale of activity will be vast, that cold chain facilities will be required and that delivery to every corner of the planet will be needed."

"We know the procedures well. What we need to do is scale them up to the magnitude that will be required," said Glyn Hughes, IATA's head of cargo.

Governments will have to ensure facilities and processes are now in place to ensure the quality of the vaccines.