(NEXSTAR) – Dr. Anthony Fauci is predicting that nearly all Americans will have access to COVID-19 vaccinations by April, as increased supply allows most people to get shots.

Speaking to NBC’s “Today Show,” the science adviser to President Joe Biden says the rate of vaccinations will greatly accelerate in the coming months. He credits forthcoming deliveries of the two approved vaccines, the potential approval of a third and moves by the Biden administration to increase the nation’s capacity to deliver doses.

Fauci says that “by the time we get to April,” it will be “open season, namely virtually everybody and anybody in any category could start to get vaccinated.”

“I would imagine, and in fact I’m fairly certain, that as we get into and towards the end of April we’ll see … pharmacies, community vaccine centers [and] mobile units really stepping up the pace of vaccination,” Fauci said.

He cautioned it will take “several more months” to deliver injections to adult Americans but predicted herd immunity could be achieved by late summer.

On Thursday, President Biden toured the National Institutes of Health Viral Pathogenesis Laboratory just outside of Washington.

The U.S. is on pace to exceed Biden’s goal of administering 100 million vaccine doses in his first 100 days in office, with more than 26 million shots delivered in his first three weeks. Meanwhile, Biden is moving to ease supply bottlenecks and ensure the nation has enough of the current two-dose vaccines to protect 300 million Americans by the end of summer.

The Associated Press contributed to this report.