COVID-19 Vaccinations by County - ARCHIVED

NOTE: As of 2/16/2023, This page is not being updated, for data on COVID-19 Updated (Bivalent) Booster Coverage go to https://data.ct.gov/Health-and-Human-Services/COVID-19-Updated-Bivalent-Booster-Coverage-By-Town/bqd5-4jgh.

Important change as of June 1, 2022

As of June 1, 2022, we will be using 2020 DPH provisional census estimates* to calculate vaccine coverage percentages at the county level. 2020 estimates will replace the 2019 estimates that have been used. Caution should be taken when making comparisons of percentages calculated using the 2019 and 2020 census estimates since observed difference may result from the shift in the denominator. 

* DPH Provisional State and County Characteristics Estimates April 1, 2020. Hayes L, Abdellatif E, Jiang Y, Backus K (2022) Connecticut DPH Provisional April 1, 2020, State Population Estimates by 18 age groups, sex, and 6 combined race and ethnicity groups. Connecticut Department of Public Health, Health Statistics & Surveillance, SAR, Hartford, CT.

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This tables shows the number and percent of people that have initiated COVID-19 vaccination, are fully vaccinated and had additional dose 1 by county of residence.

All data in this report are preliminary; data for previous dates will be updated as new reports are received and data errors are corrected.

Population size estimates are based on 2019 DPH census estimates until 5/26/2022.  From 6/1/2022, 2020 DPH provisional census estimates are used. 

A person who has received at least one dose of any COVID-19  vaccine is considered to have initiated vaccination. A person is considered fully vaccinated if they have completed a primary series by receiving 2 doses of the Pfizer, Novavax or Moderna vaccines or 1 dose of the Johnson & Johnson vaccine. The fully vaccinated are a subset of the number who have initiated vaccination. Percentages are calculated using 2019 census data (https://portal.ct.gov/DPH/Health-Information-Systems--Reporting/Population/Annual-Town-and-County-Population-for-Connecticut). 

A person who completed a Pfizer, Moderna, Novavax or Johnson & Johnson primary series (as defined above) and then had an additional monovalent dose of COVID-19 vaccine is considered to have had additional dose 1. The additional dose may be Pfizer, Moderna, Novavax or Johnson & Johnson and may be a different type from the primary series. For people who had a primary Pfizer or Moderna series, additional dose 1 was counted starting August 18th, 2021. For people with a Johnson & Johnson primary series additional dose 1 was counted starting October 22nd, 2021. For most people, additional dose 1 is a booster. However, additional dose 1 may represent a supplement to the primary series for a people who is moderately or severely immunosuppressed. Bivalent booster administrations are not included in the additional dose 1 calculations.

The percent with at least one dose may be over-estimated and the percent fully  and additional dose 1 vaccinated may be under-estimated because of vaccine administration records for individuals that cannot be linked because of differences in how names or date of birth are reported.

County of residence is determined based on the town of residence.  Town of residence is verified by geocoding the reported address and then mapping it to a town using municipal boundaries.  If an address cannot be geocoded, the reported town is used, if available.  Out-of-state residents vaccinated by CT providers excluded from this table.  People for whom an address is not currently available are shown in this table as “Address pending validation”.  

Connecticut COVID-19 Vaccine Program providers are required to report information on all COVID-19 vaccine doses administered to CT WiZ, the Connecticut Immunization Information System. Data on doses administered to CT residents out-of-state are being added to CT WiZ jurisdiction-by-jurisdiction.