BOSTON (CBS) — Testifying before a panel about the state’s COVID vaccine rollout on Tuesday, Gov. Charlie Baker restated his goal of getting more than 4 million residents fully vaccinated – a number he said is needed to reach the “herd immunity” tipping point in the fight against the coronavirus.

“To reach herd immunity in Massachusetts, we need to vaccinate about 4.1 million people fully,” Baker said.

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Herd immunity, as defined by the CDC, refers to the point at which “a sufficient proportion of a population is immune to an infectious disease (through vaccination and/or prior illness) to make its spread from person to person unlikely.”

Baker noted that so far, more than a million residents are fully vaccinated by either receiving both doses of the Pfizer or Moderna vaccine, or one shot of the single-dose Johnson & Johnson vaccine. Another group of just about one million people have received one vaccine dose and are waiting for their second.

Another million people have preregistered and are set to receive an appointment when they become eligible, Baker said. And hundreds of thousands more will go through their medical providers or retail pharmacies to set up appointments.

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“Taken together, Massachusetts has this tremendous goal in its site and we just need to follow through in this final stretch,” he said.

Another 850,000 residents could start booking appointments for the vaccine Monday as people age 60 and older and essential workers became eligible.

The total number of confirmed cases in the state is now 580,683 while the total number of deaths is 16,558.

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Visit Mass.Gov/CovidVaccine to book an appointment or call the hotline at 211. Staff