The changes were announced Monday, as public officials in the greater Washington region and across the country push to inoculate as many people as possible in hopes of stemming the rise in caseloads and variants of the deadly virus.Officials in several Northern Virginia jurisdictions — Fairfax, Prince William and Loudoun counties and the city of Alexandria — opened coronavirus vaccine eligibility to the remaining categories of essential worker: those who work in waste removal, housing and construction, food service, higher education, information technology and communication, media and legal services, as well as barbers and hairstylists.Arlington officials said they hope to follow suit by week’s end.Virginia Gov. Ralph Northam (D) has said the state will open vaccinations to the general population by April 18, and D.C. Mayor Muriel E. Bowser (D) on Monday moved up the mass eligibility date in her city from May 1 to April 19.Bowser said the city would probably ease capacity restrictions on entertainment venues and some other attractions by May 1. Recreation centers, libraries, museums and nonessential retail businesses will be able to operate at 50 percent capacity, an increase from 25 percent. Weddings, business meetings and special events will be allowed indoors and outdoors at 25 percent capacity, though a waiver will be required for events with more than 250 people. Indoor and outdoor school graduations and award ceremonies will be allowed with capacity limits.Bowser said indoor and outdoor city swimming pools, which remained closed all of last summer, will be able to operate at 50 percent capacity. Live-entertainment theaters may open at 25 percent capacity starting in May, though patrons must remain seated during performances. Live music will also be allowed at outdoor restaurants.Maryland officials urged the public to be patient, cautioning that appointments will not be immediately available for every newly eligible person. While the state said eligibility was expanding specifically for Maryland residents, officials have described vaccine doses as federal assets and said eligible out-of-state residents will not be turned away.Six mass vaccination sites are operating in Maryland, with three more scheduled to open this week in Montgomery, Prince George’s and Baltimore counties. People can register for appointments through the state’s central vaccine website or by calling 855-MD-GOVAX. The mass vaccination site in Hagerstown will begin accepting walk-up patients on Tuesday, joining the Salisbury location, which stopped requiring appointments as of Friday. Maryland Health Secretary Dennis Schrader told state lawmakers that M&T Bank Stadium in Baltimore will start offering walk-up shots next week. He said the state is trying to target young people and is working with universities to inoculate 54,000 college students before they leave campuses for summer break.While it will depend on the supply from the federal government, Hogan said he would anticipate that anyone who wants a vaccine should have one no later than April or May. He said the state has recently been vaccinating up to 75,000 people a day and would need more supply to hit the “magic 100,000-a-day number that our system can handle.”The state’s goal, he said, is “to eliminate, to wind down and shut down all of these 12 mass sites,” once all those who need vaccinations can get them at their pharmacy, at their doctor’s office or through another provider. “In the meantime we want to run as many people through there as we possibly can, thousands of them a day, because time is not our friend in this battle,” Hogan said.As of Monday, 18 percent of Virginia’s population was fully vaccinated and 32.8 percent had received at least one shot, according to state data. About 12 percent of D.C. residents were fully vaccinated and 23 percent had received at least one shot, city data showed. In Maryland, state data showed about 31 percent of residents had received at least one dose.The seven-day average of new daily coronavirus cases has crept up in Maryland over the past month, according to The Washington Post’s tracker, from 12 per 100,000 residents on March 5 to 21 per 100,000 as of Monday.The seven-day average for people hospitalized with covid-19 was 1,331 on Monday, compared with 1,098 one month ago. But the seven-day average number of new daily deaths stayed relatively flat, hovering between 13 and 18 over the course of the month.Hogan said one reason he is expanding vaccine eligibility to people 16 and older is that the age of those who are hospitalized in the state is dropping. “Young people felt that they were bulletproof or that they didn’t have to worry about it, but now we’re seeing that they do really need to worry about it,” he said. “We’re seeing fewer and fewer of our older residents getting sick or hospitalized or dying, because 76 percent of them have been vaccinated.”In the past five weeks, the proportion of new coronavirus cases affecting people over 60 has dropped significantly, said Ted Delbridge, the executive director of the Maryland Institute for Emergency Medical Services Systems. He warned people not to put off getting vaccinated. “Covid-19 is a serious illness,” he said. “Even if you are a lucky person and manage not to get so ill, the people closest to you, the ones you love, may not be so lucky.”In Virginia, the number of new daily cases has remained fairly consistent, with a seven-day average of 16 new cases per 100,000 people as of Monday, compared with 17 one month ago. The seven-day average number of hospitalizations is down to 1,024 from 1,301 on March 5, according to state data tracked by The Post.Cases have also essentially plateaued in the District, with a seven-day average of 17 new daily cases per 100,000 on Monday and on March 5. The seven-day average of hospitalizations declined from 242 one month ago to 219 on Monday.Bowser said city health officials “expect to see some increases in cases this month,” following Easter and spring break gatherings. “But with vaccinations and continued safeguards, we expect that later into the spring those cases will come down.”She announced an expansion of the vaccination clinic at the Walter E. Washington Convention Center, through a partnership with Safeway, and the launch Friday of a “high volume” vaccination site at Arena Stage on the Southwest Waterfront, in partnership with MedStar Health and the D.C. health department. Appointments for both clinics will be set up through D.C.’s online portal and call center, Bowser said.The health department said the city should be getting twice the number of vaccine doses it is currently allocated by the federal government, to accommodate the large number of essential workers who live in Maryland or Virginia but work and are getting vaccinated in D.C. The city receives about 25,000 doses per week, based on the Biden administration’s per capita formula, and has sought more doses since December.Erin Cox and Julie Zauzmer contributed to this report.