More than 1 million people received a COVID-19 vaccination in the past 24 hours, the highest figure in more than a month and a half, President Joe Biden announced Thursday as the nation works to beat back the advance of the highly transmissible delta variant of the coronavirus.

ABC News added that 562,000 of those shots were first doses, a key metric in the White House’s efforts to vaccinate millions of Americans who have so far hesitated to get inoculated. The delta variant has thrown any hopes for a vast reopening of society into disarray, with cases rising in every state in the country and hospitals from Hawaii to Arkansas running out of intensive care unit beds to treat a crush of severely ill people.

The figures released Thursday are below the peak of 3.4 million doses reported on April 13.