The state Department of Public Health said Monday that old census data are to blame for inflated COVID-19 vaccine estimates, which wrongly assert that 44 towns across Connecticut gave first doses to their residents aged 75 and older at a rate of more than 100%.
State data reported Thursday show that in Salem and Hebron, for example, the first-dose vaccination rate was about 130% for people 75 and older.
In an email Monday, DPH spokesperson Maura Fitzgerald acknowledged the error, which she said was an “overestimate” rooted in 2014 census data. She characterized that data as “the last year for which reliable estimates are currently available.”
“Since the population has aged since 2014, the population size may be … underestimated in some towns,” Fitzgerald said.
Put another way? The state is reporting a vaccination rate that’s likely higher than reality in some towns. It’s the result of comparing the larger, older population demographics of today against a smaller, now less accurate population figure from years ago.
“This is likely to be the cause of the overestimate,” Fitzgerald said. “These data are provisional, and other factors such as duplicate records may also play a role.”
Fitzgerald said that even though the numbers are likely inflated, the data still provide useful comparisons to show overall vaccination trends.
On Thursday, Gov. Ned Lamont said 78% of the state’s population aged 75 and above had gotten at least one COVID-19 vaccination shot.
Fitzgerald said those statewide numbers are based on updated 2019 population figures, not the older, less accurate 2014 data.
She said DPH hopes to incorporate the 2019 numbers into the more granular town-level vaccination data soon.
“DPH is working right now to update town by age to the 2019 census numbers, but that work is not completed yet,” Fitzgerald said.
