People 75 and older can sign up for vaccine beginning Wednesday

John Tlumacki/Globe Staff

Massachusetts embarks on the next stage of its COVID-19 vaccination program on Wednesday, extending eligibility to people 75 and older, the population most devastated by the coronavirus, amid frustration over the pace and priority of distribution.

As the Biden administration announced plans to buy 200 million more doses of the vaccine and increase weekly shipments to states, Massachusetts officials said residents 75 and over could now register for appointments at scores of immunization sites across the state. The first shots for this age cohort, approximately 450,000 people, will begin Monday.

“By the end of this week, we will have 103 vaccination sites open to the public with the ability to administer about 240,000 doses each week,” Governor Charlie Baker said Tuesday in his State of the Commonwealth address. “And by mid-February, we will have 165 public sites, including seven mass vaccination sites, and all together, we will have the capacity to administer approximately 305,000 doses every week.

All locations, which can be viewed at https://www.mass.gov/covid-19-vaccine, require appointments, and individuals must present proof of eligibility to receive the vaccine. The website doesn’t offer a single schedule form but instead links to signup pages at each location. The vaccine requires two doses that must be received at the same location, according to state officials.

Health and Human Services Secretary Marylou Sudders said earlier this week that officials would try to reach people who may not be computer-savvy through a “massive communication” to local councils on aging and organizations that work with the elderly.

But some advocates said they were worried that seniors who lack Internet access or are uncomfortable with computers would be left behind.

“It’s concerning that it’s dependent on people’s ability to sign up online, particularly given what we know about the virus’s disproportionate impact on low-income communities and communities of color,” said Carolyn Villers, executive director of the Massachusetts Senior Action Council.

“Navigating a phone is something we take for granted, like it’s another appendage. But for seniors, it’s really challenging,” she added. “Particularly for folks who may not have family to help navigate this, I think it will definitely leave many behind.”

AARP Massachusetts sent a letter to Baker and the Legislature Tuesday saying that most deaths have been among adults over 50, according to a statement from the organization, and that officials need to provide information about how to get the vaccine.

“We continue to hear from members that they do not know when, where or how to schedule an appointment. This is unacceptable,” the statement said.

The state’s phased vaccination program began in December with front-line health care workers and residents and staff of long-term-care facilities. Eligibility has expanded to include first responders and congregate care settings, such as prisons and homeless shelters.

Following recommendations from the federal Centers for Disease Control and Prevention, the state is giving higher priority for vaccination to seniors, who are at higher risk of serious illness and death from COVID-19.

The leaders of two statewide teachers unions and the Boston Teachers Union said they were alarmed by state’s new vaccination plan, which prioritizes older residents over many essential workers, including K-12 educators.

Merrie Najimy, president of the Massachusetts Teachers Association, Beth Kontos, president of American Federation of Teachers Massachusetts, and Jessica Tang, president of the Boston Teachers Union, said the new plan “will significantly delay the vaccination of educators and slow down a safe return to more in-person learning in public schools and colleges.”

“The governor keeps pushing schools to reopen for in-person learning more quickly, regardless of the risks to staff and students, yet he has just made it much harder to do that safely,” Kontos said a statement.

President Biden said Tuesday that the federal government would purchase an additional 100 million doses each of the two approved vaccines. With existing purchases, the White House expects to be able to deliver enough of the two-dose regimens to states to vaccinate 300 million people by the end of the summer or early fall. Biden called the push to increase supply a “wartime effort.”

On Monday, Baker outlined a plan to add more than 60 injection sites across the state, including three new mass vaccination locations, as state officials acknowledged that hundreds of thousands of doses were sitting on freezer shelves in hospitals and the warehouses of pharmacies serving senior care sites. State officials said they had temporarily halted vaccine shipments designated for long-term-care facilities because so many are unused.

Figures posted on the CDC website Tuesday showed that the government plans to make about 10.1 million first and second doses available next week, up from this week’s allotment of 8.6 million. The figures represent doses of both the Pfizer and Moderna vaccines.

The state has come under criticism for its vaccine guidelines, but Dr. Anthony S. Fauci, the federal government’s top infectious disease specialist, said Massachusetts is doing a “really good job” on its COVID-19 vaccine rollout compared with other states.

“When you have capabilities like Boston in the state of Massachusetts, as being able to put the vaccines in people’s arms, the discrepancy between supply and demand looks more acute and profound,” Fauci said in an interview with WBUR radio on Monday. “But that’s not uniform throughout the country.”

Federal figures show that Massachusetts, as of last week, ranked in the bottom half of states in vaccination rate. Less than 5.4 percent of Massachusetts residents had been inoculated as of Friday, compared with 8 percent of residents in Connecticut, more than 10 percent in West Virginia, and 11 percent in Alaska.

State officials said their vaccine program is on track, noting that they set clear priorities for who goes first: front-line health workers who treat COVID-19 patients, and residents most vulnerable to the virus. In comparison, they said, other states have taken “a more open access approach,” that enables them to inject greater numbers but also leaves unvaccinated some who are at higher risk.

Baker announced Monday that people who are ages 65 and older will move up in priority during Phase 2 of the state’s vaccination process. People with two or more comorbidities will become eligible for vaccines at the same time as people 65 and older.

Material from the Associated Press was used in this report. Felicia Gans of the Globe staff and Globe correspondents Nick Stoico and Charlie McKenna contributed to this report.