More than 550,000 first doses of the coronavirus vaccine have been administered in the United States with more to come, just as Congress approves another round of aid.

The U.S. government began its massive vaccination rollout last week, starting with administering the first doses of the Pfizer vaccine to front-line healthcare workers. So far, at least 556,208 doses have been administered, a number that is expected to balloon as more doses of the Pfizer vaccine and first doses of the Moderna vaccine are administered to healthcare providers and long-term care facilities.