Virginia said it would allow residents 16 or older to begin getting vaccinated against Covid-19 on April 19, joining more than 40 states that have sped up efforts to open the process to all adults as federal health officials warn about a possible fourth surge of the coronavirus.

“The Covid-19 vaccine is the light at the end of the tunnel,” Gov. Ralph Northam said in a statement. “And that light is getting brighter every day, as more and more Virginians get vaccinated.”

Inoculation efforts in the United States have sped up as states push to make more adults eligible, heeding a call from the president to rapidly expand eligibility. As of Wednesday, an average of 2.83 million shots a day were being administered across the country, according to data reported by the Centers for Disease Control and Prevention. About 31 percent of Virginia’s total population has gotten at least one shot, putting it in the top 20 states, according to a New York Times analysis of C.D.C. data.

On Monday, President Biden ordered his coronavirus response team to ensure that by April 19 there would be a vaccination site within five miles of 90 percent of Americans’ homes. It builds on his plan for states to open eligibility to all adults by May 1.