Updated

Following the recent emergency use approval of Johnson & Johnson’s COVID-19 vaccine, all U.S. adults will be able to receive a coronavirus vaccine by the end of May, President Joe Biden announced on Tuesday. 

Biden during a press conference officially announced that pharmaceutical giant Merck & Co. is teaming up with rival Johnson & Johnson to help manufacture its recently-approved COVID-19 vaccine in a bid to speed the country's vaccination efforts, a process that began slowly but has accelerated in recent weeks. 

The emergency approval of a vaccine, in addition to the collaboration between Merck and Johnson & Johnson, was key in moving the target of the vaccines being available to all adult Americans from July to the end of May, some two months sooner than initially expected. Biden credited a "stepped-up process" in seeing this timeline accelerated. 

Johnson & Johnson previously agreed to supply the U.S. with 100 million doses of its one-shot vaccine by June, but White House officials said the company had struggled with supply and material issues.

MERCK, JOHNSON & JOHNSON PARTNER ON COVID-19 VACCINE MANUFACTURING

Last week, ahead of the FDA's emergency use authorization, Jeff Zients, White House COVID-19 coordinator, said the Biden administration was working to further "accelerate the pace and timeframe" for which the company delivered the agreed-upon supply after learning Johnson & Johnson had fallen behind in their production schedule. 

COVID-19 NOT LIKELY TO BE OVER BY END OF YEAR, WHO SAYS

Increased production of the Johnson & Johson jab is an "opportunity to help address urgent vaccination needs more quickly," the president said. He also noted his goal of vaccinating 100 million Americans in his administration's first 100 days will likely be met, as the country is already "halfway to that goal" in his first 37 days, Biden said, adding he is "confident" the U.S. "will make it all the way." 

With more vaccines, the country will also require more vaccinators, Biden said, noting doctors and nurses across the country have come out of retirement to assist with these efforts. He added that thousands of federal personnel — namely those from the Federal Emergency Management Agency (FEMA), the Department of Defense, and beyond — have also aided in vaccination efforts. 

Additionally, Biden wants all states to give priority to K-12 teachers, child-care works, school staffers, and other educators, advising states to provide at least one COVID-19 vaccine to this group by the end of March. This group will also be able to use the federal pharmacy program to obtain a vaccination appointment, he said. 

CLICK HERE FOR COMPLETE CORONAVIRUS COVERAGE

In the meantime, Biden implored all U.S. citizens to remain vigilant, especially amid emerging variants of the novel disease. 

"Things may get worse again as new variants spread and as we face setbacks, like recent winter storms in the Midwest and South. But our administration will never take this public health threat lightly," Biden said. "Now is not the time to let our guard down. People’s lives are at stake."

Fox News' Alexandria Hein contributed to this report.