LONDON — Thousands of people 80 and older have started receiving invitations to get the coronavirus vaccine in England, officials said Sunday, as Britain ramps up its national vaccination program in a bid to meet its target of inoculating about 15 million people by the middle of February.

More than 600,000 invitations are due to arrive at doorsteps across England this week, asking the elderly to sign up for jabs at new mass vaccination centers near them.

The government has given a first dose of the vaccine to more than 1.2 million people so far.

The seven new large-scale vaccination centers join some 1,000 other sites across the country, including hospitals, general practitioners’ clinics and some drugstores.

Officials are hoping a speedy mass vaccination rollout will help get Britain out of its third national lockdown, which was ordered this month to curb an alarming surge of COVID-19 infections and deaths. Britain has seen 81,000 deaths in the pandemic, according to a tally by Johns Hopkins University.