More than 600,000 people in the United Kingdom have received the first dose of the Pfizer-BioNTech COVID-19 vaccine since the rollout began earlier this month.

The UK was the first country in the world to approve and begin inoculating people with the vaccine. Care home residents, adults over 80, and health and social care staff were first to receive the shot at more than 500 sites across the country.

The UK has ordered 40 million doses of the vaccine. Health Secretary Matt Hancock said that he expects to receive millions of doses before the end of the year.

The second dose must be given three weeks after the first.