LONDON — Shipments of the coronavirus vaccine developed by American drugmaker Pfizer and Germany’s BioNTech were delivered Sunday in the U.K. in super-cold containers, two days before it goes public in an immunization program that is being closely watched around the world.

Around 800,000 doses of the vaccine were expected to be in place for the start of the immunization program on Tuesday, a day that Health Secretary Matt Hancock has reportedly dubbed as “V-Day,” a nod to triumphs in World War II.

“To know that they are here, and we are amongst the first in the country to actually receive the vaccine and therefore the first in the world, is just amazing,” said Louise Coughlan, joint chief pharmacist at Croydon Health Services NHS Trust, just south of London.

Last week, the U.K. became the first country to authorize the Pfizer-BioNtech vaccine for emergency use. In trials, the vaccine was shown to have around 95% efficacy.

Vaccinations will be administered starting Tuesday at around 50 hospital hubs in England. Scotland, Wales and Northern Ireland will also begin their vaccination rollouts the same day.