D.C.-area residents expressed new frustrations Monday over how to access the coronavirus vaccine, as the pool of eligible recipients grew and the available supply was far outstripped by demand.

More than 1,400 new vaccination appointments in the District were snapped up in 25 minutes, city officials said, while people who were newly eligible in Maryland and parts of Virginia also struggled to get appointments.

In Fairfax County, Virginia’s most populous jurisdiction, the health department started accepting registrations for residents 65 and older or who are at least 16 and have a high-risk medical condition or disability that increases their chance of getting severely ill from covid-19, the disease caused by the virus.

More than 50,000 people have signed up, said health department spokesman Jeremy Lasich. But the county infrastructure right now would allow for only about 10,000 shots a week, and Lasich said the health department has been getting between 4,600 and 12,000 doses a week, with the shipments being on the lower end recently.

Some of those who went online to get an appointment Monday were sent an email with a unique link to sign up; others were told there were not enough doses to go around and put on a waitlist.

“Don’t call us, we’ll call you,” quipped one 74-year-old Annandale resident who spoke on the condition of anonymity because he worried about risking his future access to the vaccine.

Lasich said the health department heard from some residents who were confused by the messages, which he said were simply intended to provide updates on the process and assure them they are still registered.

Maryland expanded vaccine eligibility Monday to Phase 1B, which includes people age 75 and older, K-12 teachers, child-care workers, those in assisted-living facilities and incarcerated people at high risk of developing complications from covid-19.

But some residents said on community email groups and in emails to The Washington Post that appointments were hard to secure and were unavailable in some places.

A Chevy Chase resident said he found the state’s sign-up website difficult to navigate, especially for seniors who might not be as tech-savvy. The man, who is 77, said he was frustrated that he couldn’t find any available appointments in Montgomery County. He said he made an appointment for next week in another county, which he declined to name because he said he didn’t know if it was allowed.

“Something like this should be as user-friendly as possible,” he said, speaking on the condition of anonymity because he was worried about his medical privacy. “I get that it’s a tough thing to do, but we’ve known this vaccine is coming for months. It should be much smoother.”

Jinlene Chan, Maryland’s acting deputy health secretary, said no state policy requires people to be vaccinated in their home county. However, she said local health departments have discretion in doling out their doses.

Maryland Gov. Larry Hogan (R) publicly received his first dose of the Moderna coronavirus vaccine Monday, and he urged state residents to seek it as soon as they qualify. Hogan, who is 64 and had cancer, said he qualified for the vaccine under the “continuity of government” category in Phase 1B.

“The only way that we’re going to return to a sense of normalcy is through these coronavirus vaccines,” Hogan said. First lady Yumi Hogan, as well as Lt. Gov. Boyd K. Rutherford (R) and his wife, Monica Rutherford, also were publicly vaccinated.

Hogan acknowledged his state and others have faced criticism for the sluggish rollout of vaccinations. But he said the state is months ahead of schedule in expanding to other priority groups and that it is vaccinating people at a faster rate than the federal government is supplying doses. Public advocacy campaigns to encourage residents to get the vaccines are expected to launch in the next few weeks, he said.

Maryland reported 1,769 new coronavirus cases Monday, the lowest single-day tally in three weeks (reporting often slows on weekends). Twenty-nine new deaths were reported.

D.C. reported 182 new cases and seven deaths Monday — four women and three men, ranging in age from 58 to 90 years old. Virginia, which on Sunday reported a record 9,914 new cases, on Monday added 7,245 cases and 10 deaths.

D.C. resident Gail Hochhauser said she and her husband, who are both over 65, have grown “extraordinarily frustrated” trying to make a vaccine appointment in the city since becoming eligible Jan. 11.

The city shifted strategy late last week, reserving some appointments for residents of its least affluent wards, which have been hit hardest by the virus. That decision came after data showed that only a tiny fraction of the available appointments had gone to poorer residents.

Hochhauser, who is the director of development for a nonprofit, said she and her husband tried the District’s website via separate computers at 9 a.m. every day last week and again Monday. If the website didn’t crash or boot them off, she said, they would hit refresh over and over. After 20 to 30 minutes, she said, they would see, “No appointments currently available.”

When she called the city’s coronavirus alert center just after it opened at 8 a.m., Hochhauser said, she got a recording, once saying she was 196th in line and another time 220th.

She said she and her friends are worried that the vaccine will be made available to the next eligible group before medically vulnerable seniors have had a chance.

“It’s just not working,” she said.

A D.C. Health Department spokeswoman said the city is “working closely with partners around-the-clock” to improve the appointment scheduling process.

“We know how stressful of a time this is, and we will continue to advocate to the federal government for more vaccine for our residents and workers,” the spokeswoman said. “The District of Columbia will continue to make the vaccine available promptly as we receive doses, and we remain committed to ensuring an equitable distribution.”

This story has been updated to clarify how much vaccine Fairfax County has available.

Julie Zauzmer contributed to this report.