The first doses of Pfizer-BioNTech's Covid-19 vaccine arrived in the UK on Thursday -- a day after the country approved the vaccine for distribution, according to British media.
Pfizer and Downing Street declined to comment to CNN, citing security reasons.
The UK’s Department of Health told CNN that up to 800,000 doses of the vaccine are being made available next week.
The vaccines were carried by a fleet of unmarked trucks through the Eurotunnel from Belgium and are on their way to undisclosed storage facilities in England, Wales, Scotland, and Northern Ireland, according to CNN affiliate ITV News.
The in-demand vaccine will be distributed from these storage facilities early next week to 50 hospital hubs acting as vaccination points, according to the health ministry.
Earlier on Thursday, England's Deputy Chief Medical Officer, Jonathan Van-Tam, said "We expect to receive (the Pfizer vaccine) very shortly in the UK, and I do mean hours, not days," in an interview with BBC Radio.
First vaccine approval: The UK became the first western country to authorize use of a coronavirus vaccine. The country has ordered 40 million doses of the Pfizer jab, enough to vaccinate 20 million people -- roughly a third of the UK's population -- as the vaccination involves two shots administered at least three weeks apart.