Watson, a therapy dog with the police department in Pawtucket, R.I., keeps a girl company as she receives her coronavirus vaccination on Dec. 7. (David Goldman/AP)

However, the achievement comes as the nation’s tallies of daily deaths and new cases rose in the past week and hospitalization rates jumped by 10 percent. The looming threat of the newly identified omicron variant of the coronavirus also hangs over the country as it enters the holiday season.

Omicron cases have been detected in 21 states so far, according to a Centers for Disease Control and Prevention tracker, most recently in Texas on Wednesday.

The World Health Organization, drug companies and U.S. health officials have so far said omicron may prove more transmissible than previous variants but potentially cause milder cases of covid-19. However, they have issued strong caveats, saying the data is preliminary and research is ongoing to find out more about the variant, with no firm conclusions yet drawn.

The WHO said omicron cases had been reported in 57 countries as of Wednesday. World leaders, including President Biden, have put in place travel restrictions, tightened domestic measures to limit the spread of the virus and reinvigorated booster and vaccination drives. Vaccine makers say they stand ready to tweak their shots as needed and have underscored the importance of booster doses.

More than two-thirds of the eligible U.S. population has received at least one dose of a coronavirus vaccine, while some 24 percent have been fully vaccinated with a booster dose, according to CDC data.

All adults in the United States have been eligible for a vaccine shot since April. In May, shots were authorized for almost 17 million children between ages 12 and 15. An additional 28.5 million children ages 5 to 11 can now receive vaccinations, making 87 percent of the population eligible.

Senior U.S. health officials have described the ongoing crisis as a “pandemic of the unvaccinated,” urging holdouts to get the shot. In Illinois, some Democratic state lawmakers are proposing unvaccinated hospital patients pay their covid medical bills out of pocket, according to legislation put forward this week. And in Texas, a study released last month found that in all age groups, the state’s unvaccinated were 40 times more likely to die than fully vaccinated people.

Despite the vaccine milestone, an eventual “end” to the coronavirus pandemic has been hoped for since the virus first crashed ashore nearly two years ago, and as the slow-moving crisis heads into its third year, many are suffering from pandemic fatigue.

A major report released Wednesday assessing the efforts of 195 countries also concluded that each, including the United States, remains dangerously unprepared to respond to future epidemic and pandemic threats.

More than 790,000 people have died of the coronavirus in the United States so far and over 5 million globally.