Maryland residents who qualify for COVID-19 immunizations should register multiple times, and with multiple providers, for vaccination appointments while supply remains limited, the state’s acting health secretary said Monday.

“We encourage people to get on waiting lists,” said Dennis R. Schrader, the acting secretary, during a virtual Maryland Senate committee meeting.

He added that people should remove their names from registration lists once they secure an appointment somewhere.

Last week, Schrader said the Maryland Department of Health did not have a defined policy about registering for multiple appointments. His comments come Monday as appointments remain scarce and frustratingly difficult to come by, especially for older adults, those without computers and people lacking digital skills.

The race to secure vaccination appointments has intensified over the past several weeks as the illness caused by the coronavirus continues to kill thousands nationwide and as new, contagious variants circulate. Nearly 465,000 Americans have died due

to COVID-19 complications since March, including 7,193 Marylanders as of Monday, according to data from the Johns Hopkins Coronavirus Resource Center and the state health department.

Maryland has fully vaccinated about 2.49% of its population so far, Hopkins data shows. Some 646,925 state residents have gotten at least one dose, according to the health department.

Maryland has opened vaccine eligibility to more than 2 million people, including adults 65 and older, nursing home residents and caretakers, health care workers, educators, some essential workers, and people with certain health conditions who are either hospitalized or receiving outpatient treatment.

The demand for vaccinations far exceeds supply; the state currently receives an average of about 10,000 doses a day from the federal government to distribute to some 2,000 providers, and must conserve enough supply for people to receive two separate shots, three or four weeks apart depending on the vaccine brand.

Both of the authorized vaccines in the United States, made by Pfizer/BioNTech and Moderna, call for a two-dose regimen for maximum protection against serious illness. No single-dose vaccine candidate has been authorized yet in the U.S.

“As supply opens up, people will be able to get better access,” Schrader said in response to questioning Monday.

But the acting secretary’s comments sparked further concerns and questions from some state lawmakers, who described the registration process as cumbersome, inequitable and discouraging for their constituents.

“It’s really inconvenient for a lot of people to have to go to a dozen [websites],”Maryland Sen. Ron Young, a Democrat who represents Frederick County, told Schrader. “I’m having people telling me they’re calling all over the place, they’re not getting in. There’s got to be a better way.”

Young and Sen. Clarence Lam, a physician who represents parts of Baltimore and Howard counties, asked why the health department had not set up a single, one-stop website for registration.

Schrader said the current system is more equitable and efficient than a statewide website. “I don’t think that would be in our best interest,” he said. “There’s a very high risk we’d create a single point of failure.”

“Well, right now, you have a lot of different points of failure,” Lam replied.

Schrader again said he considered Maryland’s registration process sufficient as is, saying it aligns with those in the majority of other states. He also pointed to the new mass vaccination site at Six Flags America, saying that 12,000 appointments were efficiently claimed in 20 minutes.

“We are getting doses into arms, and it’s working,” Schrader said. “Until we get more supply, this is going to be a continuous problem.”

More vaccine candidates could receive the U.S. Food and Drug Administration’s emergency use authorization as soon as this month. Johnson & Johnson has applied for approval of the single-dose vaccine it developed. The drugmaker, which has contracted with a Baltimore company to produce its vaccine, would add 100 million doses by June to the nation’s supply if approved.

Monday evening, after the virtual meeting had concluded, the Anne Arundel County Department of Health canceled its second-dose vaccine clinics scheduled for Tuesday and Wednesday due to “the lack of vaccine arrival from the Maryland Department of Health.”

About 7,000 second doses have not arrived on time, the department said in an email, but deliveries are expected to come through later this week.

Charles Gischlar, a state health department spokesman, said the Maryland agency ordered the second doses this morning — “well in advance of the established ordering deadline” — and they are scheduled to arrive Tuesday.

“A Monday order/Tuesday delivery cadence is the established standard for second doses, and local health departments have scheduled their vaccination clinics accordingly in past weeks,” Gischlar said in an email.

He added that the U.S. Centers for Disease Control and Prevention has issued guidance that says people can receive their second doses up to 42 days after the first shot.

Schrader acknowledged last week that the state was experiencing a second-dose shortfall due to a communication error within the federal government. The U.S. Department of Health and Human Services said the shortfall stemmed from a state error. It was not clear whether Anne Arundel County’s shortfall was related to the previous second-dose shortage.

State health officials did not confirm how many second doses had gone missing, but did say that the problem had been resolved the next day. Last week, Schrader instructed vaccine providers to hold enough vaccine in reserve to administer second doses to people who already received one shot — rather than using their supply to give more people their first inoculation against the infectious disease, as some have recommended.

Schrader said Monday that health officials were reconciling last week’s deficit with the federal government now.