On Tuesday morning (NZST), in the skies over the US, so-called miracle flights are delivering what could be the ultimate Christmas present to a nation that's on its knees due to COVID-19.
Cargo planes from FedEx and UPS are shuttling the first shipments of a coronavirus vaccine from main hubs in Tennessee and Kentucky. Each company has been given half of the supply to safely distribute to Americans from coast to coast.
At airports, vaccine carrying aircraft have been given priority landing, something usually reserved for aircraft in emergency situations.
In Kentucky, it wasn't plane spotters at the airport watching flights take off, it was people keen to witness the departure of the historic and hopefully life-changing flights.
"I just had to see it for myself," one woman told a local news station, wiping away her tears.
The gravity of the mission wasn't lost on Andrew Boyle, co-president of Boyle Transportation, which was hired by UPS to help ferry the vaccine.
"Today, we're not hauling freight, we're delivering hope," he said.
And it's not just the mobilisation of these flights that is critical: onboard the vaccine has to be kept at -70C for the entire journey. To put that into perspective, the coldest temperature ever recorded at Scott Base in Antarctica was -57C in September 1968.
Since the beginning of the COVID-19 pandemic, FedEx has delivered more than 55 kilotons of personal protective equipment (PPE), including more than two billion face masks.
Raj Subramaniam, president and chief operating officer of the FedEx Corporation, says this mission may be one of the most important it ever carries out at as a company, but says it's almost as though the network the company has built over nearly 50 years was custom built for this sort of deployment.
The FedEx network consists of more than 5000 facilities, more than 670 aircraft, more than 180,000 vehicles and nearly 600,000 team members worldwide.
At present, FedEx operates nearly 32,000 flights per month, and has more than 90 cold chain facilities across five continents with plans to open additional facilities in coming years.