WASHINGTON (NEXSTAR) — After getting emergency use approval from the federal government over the weekend, millions of doses of Johnson & Johnson’s COVID-19 vaccine are en route to points across the country.

“Doses will be delivered as early as tomorrow,” White House COVID-19 Response Team coordinator Jeff Zients said during a Monday briefing.

Like the federal government has been doing with all vaccines, the set of nearly 4 million Johnson & Johnson doses will be distributed among states proportionately by population.

“So for example, if a state represents 2% of the U.S. population, it receives approximately 2% of the Pfizer allocation,” he explained.

The White House team says the distribution of the Johnson & Johnson vaccine is a significant step in the fight against the pandemic, saying that with three options available, they hope to reach more members of vulnerable populations.

“Increased vaccine supply creates greater opportunity for people to get vaccinated,” Dr. Marcella Nunez-Smith, who is heading up the Biden administration’s COVID-19 Health Equity Task Force, said.

The vaccine has an 85% efficacy rate, it’s the first one available that requires only a single shot and it doesn’t require the low refrigeration points of Pfizer and Moderna’s doses. Nunez-Smith said the refrigeration requirements will be key in getting vaccines to underserved rural communities and communities of color.

With variants spreading quickly and the nation still a long way from herd immunity, she urged people not to be picky.

“Get the first vaccine that is available to you when it is your turn,” Nunez-Smith said.

Johnson & Johnson said it is working to deliver 16 million more doses by the end of March.