Just as Massachusetts sets its sights on Phase 4 of its reopening plan, the state has marked another milestone: 1 million people vaccinated against COVID-19.

The state surpassed the seven-figure vaccination mark on Friday, according to Gov. Charlie Baker.

“Massachusetts has now fully vaccinated over 1 million people and continues to be a national leader in vaccine administration,” he said on Twitter. “Thank you to everyone who has supported this progress!”

Having 1 million people vaccinated is a quarter of those necessary to achieve herd immunity in the state. Baker has said he hopes to have just over 4 million of the state’s almost 6.9 million residents vaccinated by the Fourth of July.

“We ran a pretty decent [vaccination] program so far, despite the bumps along the way,” Baker told The Boston Globe in a recent interview.

Earlier this week, Baker also announced the vaccine eligibility dates for remaining residents — everyone over age 16 will be eligible to make an appointment starting April 19 as the state anticipates receiving more vaccines from the federal government. Currently, residents over the age of 65, those with two or more of certain medical conditions, and most education workers are eligible, along with those under Phase 1 of the three-phase rollout.

On Monday, eligibility opens to people 60 and over and those working in certain industries. Then, on April 5, eligibility opens to people 55 and over and those with one of the qualifying medical conditions, according to the state timeline.

Baker has said he hopes to have made a large dent in the vaccine goal by Memorial Day. Surveys indicate that Massachusetts has one of the highest percentages of people who anticipate getting a vaccine.

Despite the vaccine news, public health experts are urging caution considering that the nation’s overall number of COVID-19 infections has plateaued after it was on a decline. The country is still seeing about 50,000 new cases a day, according to Dr. Ashish Jha, dean of Brown University School of Public Health.

“Even hospitalizations are inching up in some places,” Jha wrote in a recent Twitter thread. “Not a surprise. B.1.1.7 probably represents about 40% of infections in U.S. today. Means about 20,000 infections identified today were likely from B.1.1.7. It will become the dominant variant in [the] next couple of weeks.”

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