U.S. President Joe Biden held a ceremony on Thursday to commemorate 50 million coronavirus vaccine stings, amid growing concerns about the emergence of new variants in at least two states.

Biden, who took office on January 20, promised to vaccinate 100 million people in his first 100 days in office. Now, on his 37th day in office, Biden said he was on track to exceed that goal.

“I’m here today to report that we’re halfway through,” Biden said, adding that he would also celebrate the 100 million dose once it is hit.

Three people – a firefighter, a nurse, and a pharmacy worker – were vaccinated during the television ceremony held at the White House Thursday.

“We are moving in the right direction,” he said, “despite the chaos we inherited from the previous administration that left us with no real plan to vaccinate all Americans.”

Washington, DC firefighter EMT Corey Hamilton receives a dose of the Pfizer vaccine during an event to commemorate the 50 millionth COVID-19 vaccination in Washington [Jonathan Ernst/Reuters]The US vaccinated an average of 1.3 million Americans a day, but that rate was derailed last week after severe winter storms across much of the country affected transportation and resulted in dozens of vaccination sites being temporarily closed.

That rate could rise soon. The U.S. could grant emergency approval for Johnson & Johnson’s single-dose vaccine this week after the U.S. Food and Drug Administration (FDA) released documents showing the vaccine against the coronavirus is safe and effective.

A regulator of independent experts is due to meet on Friday to decide whether to approve the shot. If approved, Biden said they “will be rolling it out as soon as Johnson & Johnson can get it”.

The urge to vaccinate more Americans is taking place amid a steady decline in new cases, hospitalizations, and deaths, but it is also happening amid the emergence of two varieties that some researchers say may be more transmissible and resistance to currently available vaccines show administered.

New variants

A new variant of coronavirus, which shares some similarities with a more communicable and difficult-to-treat variant discovered in South Africa, is on the rise in New York City, researchers said Wednesday.

Columbia University researchers found that variant B.1.526 has some worrying properties with B.1.351, the strain first identified in South Africa, and P.1., First identified in Brazil. Several studies have shown that these new variants are more resistant to some existing vaccines than previous versions of the coronavirus.

New York Health Commissioner David Chokshi said Thursday that the city is following the variant “very closely”.

“We currently have no evidence that the variants, this New York variant, the 1,526, contribute to the trajectory of the cases that we should emphasize are continuing to decline,” Chokshi said at a press conference.

Navy personnel prepare doses of the COVID-19 vaccine before a mass vaccination site opens in Queens, New York [Seth Wenig/Pool via Reuters]Researchers in California also discovered a new variant that may be more contagious than the original strain, according to a study published in the JAMA Medical Journal on Feb.

The study found that the California strain CAL.20C first appeared in July last year, accounting for around 35 percent of all COVID-19 cases in the state and 44 percent of the samples collected in January. According to the U.S. Centers for Disease Control and Prevention (CDC), the spread of CAL.20C has increased since September.

Charles Chiu, professor of laboratory medicine and infectious diseases at the University of California’s San Francisco School of Medicine and chief scientist on coronavirus mutations, said that variants – even if they are highly transmissible – are still controlled through social distancing and wearing masks can, wash hands, continue to vaccinate people.

“Basically, this does not change the direction we are going,” Chiu told the Washington Post. “That means we want to stop cases in which we can bring the pandemic under control.” Just having one more contagious variety around won’t mean the end of the world. “

Other studies have shown that recently introduced coronavirus vaccines are likely to still neutralize the virus and protect it from serious illness, even when infected with new variants. Vaccine manufacturers are also working on developing booster shots to fight mutated versions of the virus.