Until now, officials have avoided specifying dates for the rest of the rollout, instead concentrating on providing shots for the million or so people who are currently eligible: senior citizens, people with two or more chronic health conditions, and teachers and educators.
Two other large groups — about 360,000 workers in a range of essential industries, and 430,000 people with one chronic health issue, according to the state — are still expected to be added to the mix before Massachusetts ends all restrictions and opens vaccine appointments to a final 2.55 million people in the general population over the age of 16.
The state’s vaccine website has long said the Baker administration intends to open appointments to the general public at some point in April, ahead of the Biden deadline. And officials noted that the state has generally followed the eligibility schedule on the website aside from a few unexpected changes along the way, such as adding educators to the mix.
Baker has also stressed that the biggest question in quickly opening vaccines to all adults is whether the federal government can significantly increase the supply of vaccines.
“I welcome President Biden’s [May 1 deadline] and redouble my call on the federal government to do everything in its power to increase vaccine production to meet the massive demand,” the governor said in a statement last week.
As the pace of the Massachusetts vaccine drive picked up in the last month, experts said the state could be trailing others in opening eligibility for a number of reasons. There are demographic considerations, for example: states with older populations or larger health care workforces may take longer to get through that pool.
Dr. Ashish Jha, dean of the Brown University School of Public Health, said there may be a negative reason some states are able to open eligibility more quickly: a lower level of demand for the vaccine among the eligible population and more people who are unwilling or unable to get vaccinated.
“Some states have been able to move fast because they have a lot of hesitancy, and a lot more people aren’t getting vaccinated,” Jha said. “Swinging doors wide open . . . isn’t necessarily a sign that you’re doing things great.”
In Massachusetts, some older residents who are not yet eligible have worried they will struggle to get an appointment when the general public is allowed, because there will be so much competition. Under the state’s current guidelines, a 64-year-old without any health conditions would become eligible at the same time as a 16-year-old, and may actually be vaccinated after that person.
“Are they going to do some sort of scramble, or are they going to see we have a lot of people age 64 and take so many from each age group?” asked Pam Cirincione of Wakefield, who, at 64, is less than a year shy of being eligible.
Some states, including Connecticut, Maine, and Rhode Island, plan to more gradually increase eligibility by incrementally reducing the minimum age before later opening to everybody, a maneuver that Maine Governor Janet Mills said was intended to better balance supply and demand.
The Baker administration said in early March that it will consider the idea, but has since declined to further comment.
The governor has said Massachusetts has the capacity to greatly increase the number of shots given per day at various sites, but only with greater supply. Baker has also called on the federal government to provide a longer-term forecast of how many doses states will receive each week to help with planning and scheduling.
There are some signs that supply is picking up. The state this week is receiving more than 170,000 new first doses from the federal government, a nearly 9 percent increase from last week, buoyed by 8,000 doses of the Johnson & Johnson vaccine that officials did not expect.
Over the last month, the state has received on average about 168,000 first doses a week from the federal government, compared to about 102,750 in the previous four-week span, according to the Centers for Disease Control and Prevention. Still more doses are delivered and administered in the state through federal programs at CVS pharmacies and community health centers.
And public health analysts widely expect the supply to continue to march upward in the coming weeks, with some viewing nationwide eligibility by May 1 as an easily accomplishable goal.
“May 1 has become the default across most states, if not all states,” said Josh Michaud, associate director for global health policy at the Kaiser Family Foundation. “To my mind, it means there is a lot of confidence in the federal government that there will be enough doses.”
Biden emphasized that he does not expect anybody who wants a shot will be able to get one by May 1. As the floodgates open and millions more people enter the system, it will still likely take weeks to get everybody appointments — even with increased supply.
Massachusetts has already experienced what can happen when too many people flood the vaccine system. In February, when the state expanded eligibility to all people over 64 and with multiple health conditions, residents struggled for weeks to book appointments and the state’s website initially crashed from all the traffic. Some experts have questioned whether Massachusetts and other states opened up eligibility too quickly at a time when demand so heavily outstripped supply.
“If you have to include a warning statement [that scheduling will take weeks] at the beginning, that suggests maybe they should have been a little bit more judicious,” said Dr. Eric Toner, a senior scholar at the Johns Hopkins Center for Health Security.
But there have been changes to the Massachusetts sign-up process in the weeks since, most notably with the launch of a new preregistration system that manages all the demand and puts eligible residents into a digital queue.
While preregistration doesn’t solve supply and demand issues, it could eliminate much of the angst in a scheduling process that previously forced people to constantly check and refresh a website in desperate hope for an opening. Now, residents can sign up to be put in line, and notified when a nearby appointment is available to be booked.
Anybody can preregister, but only eligible residents will be put in the queue on a first-come, first-serve basis. The state says there will be no such advantage for noneligible people who sign up early. They will instead only enter a queue on the date their population is deemed eligible by the state, and will be randomly assigned a place regardless of when they signed up, officials said.