Gov. Charlie Baker announced that more than 35,000 new COVID-19 vaccination appointments would go live Thursday at sites across the state, but added that many of them have already been booked.
The new appointments included 20,000 at the Fenway Park and Gillette Stadium mass vaccination sites, he said, all of which are already spoken for.
Another 15,000 vaccination appointments were added at mass vaccination sites in Danvers and Springfield, and those were still in the process of being booked as of midday Thursday.
"We're talking about really large numbers here," Baker said. "We can't expect everyone's going to get vaccinated right away."
"The biggest challenge for this is more vaccines, more slots, which will make it possible for more people to book," he added.
Baker said tens of thousands of new appointments will open up at the mass vaccination sites each Thursday, and smaller vaccination sites at CVS, Walgreens, Price Chopper and community health centers will post them more frequently but will have fewer slots to fill to begin with.
"If you don't see an opening, you should just go back and go back to that site each day," he said. "Eventually, an opportunity will become available and you can take it."
Baker spoke Thursday from the 1620 Winery in Plymouth, where he announced another $45 million in grants to 1,100 small businesses impacted by the COVID-19 pandemic. So far, the state has given out $280 million in grants to 5,800 small businesses.
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All Massachusetts residents age 75 and older are now eligible to make an appointment to get a COVID-19 vaccine, but Wednesday’s online rollout did not go smoothly for many.
There were numerous accounts of older residents who could not navigate the state-run website or waited hours only to find that all slots were already full. Several lawmakers in that age range slammed the system as confusing and even "ineffective."
The second phase of the administration's vaccine rollout plan will begin next week, making doses available to residents 75 and older to start.
In his State of the Commonwealth address Tuesday night, Baker said residents could start using the state's website -- mass.gov/covidvaccine -- to check their eligibility and book appointments for vaccines.
Senate President Emerita Harriette Chandler, who is 84, and Sen. Patricia Jehlen, who is 77, tweeted nearly identical messages Wednesday that they "personally struggled" to use the vaccination website now that they both are set to become eligible.
"My office has heard from dozens of frustrated constituents, and I expect that is only the tip of the iceberg," Chandler said in her tweet. "We are trying our best to help, but this website is simply ineffective."
Baker said Thursday that he's heard from many people that the state needs some sort of a call center that people who can't use the online system can access.
"We agree with that, and that will be happening next week," he said.
Baker said Wednesday that it is hard to answer specific questions about issues with the website. He urged younger residents to help their older friends and family navigate any technological hurdles while hinting that the administration "is working to create additional resources" to make appointments.
Asked why New Hampshire runs a single centralized online system for vaccines but Massachusetts does not and whether the difference in populations is a factor, Baker replied, "I don't know, but I will see if we can get an answer to that question."
He added that there are more than 1 million Massachusetts residents over the age of 75 who will gain eligibility to receive vaccines starting Monday, meaning the single group that will kick off Phase 2 outnumbers the state's entire vaccine haul so far.
"It's going to take a while for that collection to work their way through a system that went form 80,000 a week to 100,000 a week," Baker said Thursday. "That's better, but you're still talking about 100,000 first doses in a situation where you have almost 10 times that many who are eligible."
Federal officials plan to boost the amount of vaccines distributed to states, territories and tribes by roughly 17% for the next three weeks, up to a minimum of 10 million doses per week in that span.
However, according to Baker, the Biden administration stressed during a Tuesday call with governors that the additional supply might vary by state.
"The conversation we had with the administration was about a national number, but they said we should be careful about projecting that national adjustment to our own states," Baker said Wednesday, referencing the call organized by the National Governors Association. "We haven't heard officially what that will mean for Massachusetts."
"I'm hoping by tomorrow, certainly by Friday, we'll know what the answer to that is," Baker added. "I heard the same 17% number, but they made very clear to us: don't just assume that means you're going to get 17% (more) of what you have."