Here’s how officials explained the Massachusetts vaccine website crash

Gov. Charlie Baker's administration is apologizing for the "frustration and inconvenience that our residents experienced over the course of the day."

A screenshot of the state vaccine website as newly eligible residents tried to book appointments Thursday morning. File

The Massachusetts vaccine appointment website is back up and running.

But after technical issues plagued the the website Thursday as the state expanded eligibility to nearly 1 million new residents, Gov. Charlie Baker’s administration is apologizing for the “frustration and inconvenience that our residents experienced” in the scramble to book the scarce appointments.

In a statement Thursday night, a spokesperson for the state’s COVID-19 Command Center said that PrepMod, the vendor that manages the state’s vaccine website, had “addressed the issues,” after the more streamlined portal completely crashed for roughly two hours due to the morning rush of traffic. The spokesperson said that officials were “now pressure testing the site to ensure the vendor’s adjustments are adequate.”


Baker said Thursday that the state had done some “scenario work” ahead of time, but acknowledged that their preparation “didn’t adequately prepare the site.”

Tiffany Tate, the CEO of the nonprofit that runs the PrepMod software, told Boston 25 News that the website got an “unexpected surge” of about 2 million hits in less than an hour Thursday.

“It typically gets 1,000 per minute,” Tate said. “This morning, it got 70,000 per minute.”

However, she told the outlet Thursday that residents “have every right to be frustrated.” In a statement to media outlets, PrepMod said the system had generally performed well since it was implemented, but “did not scale fast enough to accommodate” the “sudden and unprecedented surge in traffic to the site.”

The state’s COVID-19 Command Center said Thursday night that it “will continue to work on website improvements to streamline and improve this process.”

The website crash, as well as delays that persisted throughout the day, came as residents between the ages of 65 and 74 and those with certain medical conditions were for the first time allowed to book appointments for the coming week on Thursday morning. State officials had planned to release 70,000 new appointments across the state’s six mass vaccination sites.


In the statement, officials said that residents did manage to book 60,000 new appointments Thursday, and that the mass vaccination sites were completely booked.

“A small number of appointments for other locations will be posted over the next several days,” the statement said. “This includes pharmacies and regional collaboratives.”

Due to the limited national supply of vaccine doses, officials have repeatedly said that it will take about a month for the newly eligible group of residents to book appointments. However, the repeated issues with the state’s vaccine appointment website has intensified frustrations with the rollout and led to a planned State House oversight hearing next Thursday on the Baker administration’s preparedness.

Baker said Thursday that he is “going to work very hard to make sure it doesn’t happen again.”

Get's browser alerts:

Enable breaking news notifications straight to your internet browser.


This discussion has ended. Please join elsewhere on