LONDON, United Kingdom (AP) — Britain said Sunday it has secured two million more doses of a promising coronavirus vaccine as it gears up to launch within days the country’s most ambitious inoculation program in decades.

The UK has had Europe’s deadliest coronavirus outbreak, with more than 58,000 confirmed virus-related deaths. It now hopes to hit a more positive milestone by becoming one of the first countries in the world to start vaccinating its population against COVID-19.

The UK government has agreed to buy more than 350 million doses of vaccines from seven different producers, should they prove effective, as it prepares to vaccinate as many of the country’s 67 million people as possible.

The Department of Health said Sunday it had increased its order for a vaccine developed by US firm Moderna from five million to seven million doses, enough for 3.5 million people.

The Moderna vaccine is expected to be referred soon to the UK’s Medicines and Healthcare Products Regulatory Agency, to see if it is safe and effective. Two other vaccines — one developed by Pfizer and German firm BioNTech, the other by Oxford University and AstraZeneca — are already being assessed by the regulator, the final stage before being rolled out.

Britain has ordered 40 million doses of the Pfizer/BioNTech vaccine and 100 million doses of the Oxford/AstraZeneca vaccine.

Hospitals in England have been told they could receive the first doses of the Pfizer shot as early as the week of December 7 if it receives approval, the Guardian and Financial Times reported. The US vaccination program also hopes to begin inoculating some Americans in December.

The government says frontline health care workers and nursing home residents will be the first to be vaccinated, followed by older people, starting with those over 80. The plan is to work down the age and risk groups until everyone 18 and over has been inoculated.

Peter Openshaw, professor of experimental medicine at Imperial College London, said he “wouldn’t be too surprised if an announcement would be made within the next two weeks, possibly even as early as next week”.

Non-medical staff including volunteer first-aiders are already being trained to give the shots, which will be administered at around 1,000 community vaccination centres and 40 to 50 large-scale facilities in stadiums and conference venues, according to a government planning document.

Prime Minister Boris Johnson said officials hope to vaccinate “the vast majority of the people who need the most protection by Easter”.

Writing in the Mail on Sunday, Johnson said the roll-out of a vaccine could be “just days away”. But he said there would not be a quick end to the onerous restrictions on business and everyday life that have been imposed to curb the spread of the virus.

“There are still long weeks and months ahead before we can be completely confident that we can vaccinate enough people in the country, and thereby remove enough targets for the virus, in order to beat the disease,” he wrote.

A four-week national lockdown in England is due to end Wednesday, and will be replaced by a three-tiered system of regional measures. The vast majority of the country is being put into the upper two tiers, meaning most people will be barred from meeting up with friends indoors, pubs and restaurants still face restrictions and everything from large weddings to choir practices are being banned.

Pfizer and BioNTech say their vaccine is 95 per cent effective, according to preliminary data. It must be stored at ultra-cold temperatures of around minus 70 degrees Celsius (minus 94 Fahrenheit). The Moderna vaccine, which also needs to be stored at freezer temperatures, was also about 95 per cent effective in clinical trials, the company said.

The Oxford-AstraZeneca vaccine can be stored at conventional refrigerator temperatures, making its distribution much simpler, and is also cheaper than its main rivals. But some scientists have questioned gaps in its reported results.

Oxford and AstraZeneca reported this week that their vaccine appeared to be 62 per cent effective in people who received two doses, and 90 per cent effective when volunteers were given a half dose followed by a full dose. They said the half dose was administered because of a manufacturing error, and they plan a new clinical trial to investigate the most effective dosing regimen.

Full data from the Oxford-AstraZeneca trial is expected to be published soon, and may answer some of the questions about the vaccine.

Openshaw said he’d be happy to get any vaccine that is approved.

“If my GP rings me and says ‘I’ve got an approved vaccine,’ I really don’t care which one it is,” he told the BBC.