United Airlines Holdings Inc. began charter flights to send doses of Pfizer and BioNTech's COVID-19 vaccine, ahead of approval from regulators.

United Airlines Starts Shipping Pfizer’s COVID-19 Vaccine to Distribution Centers
A United Airlines plane takes off above American Airlines planes on the tarmac at Los Angeles International Airport (LAX) on October 1, 2020 in Los Angeles, California. Mario Tama/Getty Images

People familiar with the matter told Wall Street Journal that initial flights by United Airlines link to a global supply chain being assembled to tackle the hurdles of distributing the COVID-19 vaccine.

This move was Pfizer's way of moving quickly if its COVID-19 vaccine gets approval from the Food and Drug Administration (FDA) and other regulators.

According to The Hill, the United Airlines flights for Pfizer's shots were supported by the Federal Aviation Administration.

"As a result of the historic pace of vaccine development through Operation Warp Speed and careful logistics planning, the FAA today is supporting the first mass air shipment of a vaccine," a statement from the FAA on Friday read.

The airline with fly between Brussels International Airport and Chicago O'Hare International Airport for the effort to distribute, said a report from FOX News.

According to Pfizer, its vaccine candidate's late-stage clinical trial showed that it was 95 percent effective against the coronavirus.

Its request for emergency use approval was filed to the FDA last week.

Pfizer Expands Storage Capacity at Distribution Sites

Pfizer expanded the storage capacity of its distribution sites in several sites, including those in Pleasant Prairie, Wisconsin and the city of Karlsruhe in Germany.

As part of its distribution plan, the drugmaker also plans to include refrigerated storage sites at its final-assemble centers in Kalamazoo, Michigan and Puurs, Belgium.

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Pfizer's corporate headquarters stand in midtown Manhattan on a morning where volunteers with Doctors Without Borders dumped $17 million in fake money outside of the building to protest high vaccine prices on November 12, 2015 in New York City. Spencer Platt/Getty Images

To distribute the vaccine across the globe, the drug company said it plans to use suitcase-size frozen storage in cargo planes.

Since the Pfizer vaccine was fast-tracked, it has to be kept at below freezing temperatures so special storage and transport accommodations have to be met for it to remain effective.

It has to be stored at temperatures as cold as minus 70 degrees or lower.

Pfizer and United Airlines declined to comment on the plan, but other airlines are also preparing for future shipments of COVID-19 vaccines, said FOX.

FAA Provides Guidance in COVID-19 Vaccine Distribution

In connection to Pfizer's plans, United Airlines will be allowed to carry five times the amount of dry ice normally allowed to keep the vaccine at the needed cold temperature.

Andrew Peterson, an assistant professor at George Mason University also said that storing Pfizer inoculation would be a "Herculean task."

"Beyond the challenge of physically transporting the vaccine by air and land to distribution centers across America and internationally, there are the additional obstacles of keeping the vaccine at sub-zero temperatures and monitoring deliveries for theft," he told FOX.

As many manufacturers, air carriers and airport authorities work towards distributing any vaccine to fight the pandemic, the FAA works to provide guidelines.

It helps in implementing existing regulatory requirements for safely transporting large amounts of dry ice, which can be a hazardous material.

In October, the FAA established its own COVID-19 Vaccine Air Transport team to ensure "safe, expeditious, and efficient transportation of vaccines," the agency said.

To speed up the distribution of vaccine, all flights connected to vaccine cargo was ensured the highest safety levels and around-the clock air traffic services.