Massachusetts opened vaccination appointments to residents in Phase Two, Group two of the state’s vaccine rollout plan Thursday.

The move extends vaccines to residents 65 and older, people with two or more medical conditions, such as cancer and kidney disease — as well as those who smoke or are pregnant — and residents and staff of affordable senior living spaces, according to a press release from the governor’s office. 

An additional 1 million people are now eligible to schedule appointments, according to the press release, but due to “extremely high demand for appointments and limited vaccine supply,” it could take some residents more than a month to schedule one.

As of Monday, Massachusetts has administered 84.6 percent of the doses distributed to the state, and only about five percent of the population is fully vaccinated, according to the Centers for Disease Control and Prevention.

When residents visited the State’s VaxFinder website to book appointments Thursday, the site crashed and left many unable to schedule their vaccine. The State reported in a tweet that the website was “experiencing delays and technical difficulties” during the surge of online users.

A total of 70,000 new appointments were made available at mass vaccinations sites including Eastfield Mall in Springfield, Gillette Stadium in Foxborough and Fenway Park, in addition to more than 170 additional locations including retail pharmacies, according to the press release.

As of Monday evening, there were no known vaccine appointments available in or around Boston, according to VaxFinder.

Paul Beninger, an associate professor of public health and community medicine at Tufts University, said the vaccine distribution in Massachusetts has not moved as quickly as needed.

“It’s something of a travesty of efficiencies that they haven’t ramped up,” Beninger said. “They’ve really not been as competent or as capable as they should be in actually having the systems in place to be able to manage the logistics, the scheduling and the prioritization.”

Massachusetts currently ranks 32nd in the nation in percentage of allotted vaccine doses distributed — up from 43rd at the beginning of the month.

Beninger said slow rollout for Phase Two, Group one, which includes individuals over the age of 75, created a “bottleneck.”

Cambridge-based CIC Health is organizing the mass vaccination effort at Gillette Stadium and Fenway Park. CIC Health administers the Moderna vaccine at Gillette and Pfizer’s at Fenway Park.

In addition to the 65 plus age group, individuals 16 and older with two or more certain medical conditions are also eligible to be vaccinated beginning Thursday, according to the press release. Some of the conditions are respiratory issues such as moderate-to-severe asthma, chronic obstructive pulmonary disease and smoking.

Across the state, 14.8 percent of men and 12.6 percent of women reported smoked, according to 2017 survey results published by the Massachusetts Tobacco Cessation and Prevention Program. 

Beninger noted that smokers are at a higher risk for respiratory illnesses.

“It’s one of those social pariahs, smoking,” Beninger said. “[People should] just be more sensitive to the real physical or physiological risks that are associated with those behaviors and be careful about the judgmental aspect.”

Beninger said retail pharmacies and primary care physicians are the way to expand vaccinations across the Commonwealth, especially in more densely populated areas.

“A lot of more traditional populations of patients respect and value their doctor,” he said. “You need all the different types of venues because there are different social, different philosophical, different patient factors that go into it.”