Uncertainty abounds in vaccine eligibility numbers

WHEN THE MASSACHUSETTS COVID-19 Command Center calculates how many people are eligible for vaccinations in each of the state’s three phases, there’s a problem: The total number is 1 million more adults than actually live in the state.

The main reason is that the state is double counting many individuals in these estimates.

As a result, while the Command Center has said an estimated 2.55 million people could become eligible for vaccinations in the final group – generally healthy people between ages 16 and 55 who are not essential workers – the uncertainty in the numbers raises the possibility that the final group may be smaller than expected.

The state estimated that 770,000 people were eligible in Phase 1 of vaccinations, which covered health care workers, first responders, and people living in nursing homes, prisons or other congregate care settings.

Phase 2 is the largest group, with an estimated 3.4 million people, according to the COVID-19 command center. That group now includes anyone 55 and older, educators, a host of other essential workers, and anyone with at least one medical condition that puts them at high risk of COVID-19.

The state says the remaining eligible population, Phase 3, is around 2.55 million.

The problem is that adding those eligibility groups together gets to 6.72 million adults over age 16 (children cannot get the shots). Based on publicly available census data, Massachusetts’ adult population is approximately 5.6 million, a number the Command Center agrees with.

The main reason for the 1.1 million mismatch, according to the Command Center, is that people are double counted.

The state did exclude nursing home residents who are in Phase 1 from its count of other 75 plus residents in Phase 2. But anyone whose job or health condition places them in Phase 1 or 2 was not excluded from the age-based calculations. So a 30-year-old pregnant accountant vaccinated in Phase 2 is also included in the 2.55 million Phase 3 number. A 60-year-old health care worker vaccinated in Phase 1 is also included in the Phase 2 numbers.

That means there is no way to then know how many people are actually in each phase, and which groups are smaller than anticipated.

But there is some indication that some people not officially eligible until later stages based on age, health, or profession got vaccinated earlier. This could have been done legally – because they were a companion for someone over 75 or they secured a leftover dose – or it could mean they got a vaccine improperly.

Under the state guidelines in place through this past weekend (before more people became eligible Monday), 2.44 million Massachusetts residents were eligible for vaccines, according to the Command Center’s estimates. As of Sunday, March 21, 1.92 million people had gotten a first dose of a vaccine, which would come out to 78.8 percent of the number of eligible individuals.

Baker said Tuesday that almost 80 percent of residents 75 and older had received at last one vaccine dose and more than 70 percent of those 65 to 74. But it is unlikely that every eligible group has a vaccination rate that comes out to a the nearly 79 percent average. For example, news reports have cited data showing that just 50 percent of state correction officers have gotten the vaccine.

One wild card is the state lets anyone get a shot who lives, works, or studies in Massachusetts, so it is possible that the eligible population is slightly larger than the census figures would suggest. For example, a health care worker commuting from Connecticut could get a vaccine here. The other caveat is these numbers are estimates, not exact figures.

The bottom line is people are getting vaccinated. And the expected crush of 2.5 million people who can only get vaccines after April 19 may not be as large as anticipated. But exactly how large that final group will be, we don’t know.