This table will no longer be updated after 5/30/2024 given the end of the 2023-2024 viral respiratory vaccine season.

This table shows the cumulative number and percentage of CT residents who have received an updated COVID-19 vaccine during the 2023-2024 viral respiratory season by age group (current age).
CDC recommends that people get at least one dose of this vaccine to protect against serious illness, whether or not they have had a COVID-19 vaccination before. Children and people with moderate to severe immunosuppression might be recommended more than one dose. For more information on COVID-19 vaccination recommendations, click here.
• Data are reported weekly on Thursday and include doses administered to Saturday of the previous week (Sunday – Saturday). All data in this report are preliminary. Data from the previous week may be changed because of delays in reporting, deduplication, or correction of errors.
• These analyses are based on data reported to CT WiZ which is the immunization information system for CT. CT providers are required by law to report all doses of vaccine administered. CT WiZ also receives records on CT residents vaccinated in other jurisdictions and by federal entities which share data with CT Wiz electronically. Electronic data exchange is being added jurisdiction-by-jurisdiction. Currently, this includes Rhode Island and New York City but not Massachusetts and New York State. Therefore, doses administered to CT residents in neighboring towns in Massachusetts and New York State will not be included. A full list of the jurisdiction with which CT has established electronic data exchange can be seen at the bottom of this page (https://portal.ct.gov/immunization/Knowledge-Base/Articles/Vaccine-Providers/CT-WiZ-for-Vaccine-Providers-and-Training/Query-and-Response-functionality-in-CT-WiZ?language=en_US)
• Population size estimates used to calculate cumulative percentages are based on 2020 DPH provisional census estimates*.
• People are included if they have an active jurisdictional status in CT WiZ at the time weekly data are pulled. This excludes people who live out of state, are deceased and a small percentage who have opted out of CT WiZ.
* 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.

The spread of the COVID-19 Delta variant has prompted many governments, schools, and companies to institute vaccine mandates. Proponents suggest that mandates will enhance public health and increase vaccination rates. Critics suggest that evidence of mandates’ effectiveness is unclear and warn that mandates risk increasing societal inequalities if unvaccinated minority groups opt out of educational, commercial, and social activities where mandates are required. We conduct an original survey experiment on a representative sample of 1,245 Americans to examine the efficacy and effect of COVID-19 mandates. Our findings suggest that mandates are unlikely to change vaccination behavior overall. Further, they may increase the likelihood that sizable percentages of the population opt out of activities where vaccines are mandated. We conclude that mandates that do go into effect should be accompanied by targeted, persuasive communications targeted to specific information needs and identities.

Context

Vaccinations provide people the ability to develop immunity to particular diseases. When the majority of a population is vaccinated, “herd immunity” protects those who have not been vaccinated by blocking the spread of these diseases. A medical research paper published by The Lancet in 1998 suggested an association between the Measles/Mumps/Rubella (MMR) vaccine and Autism spectrum disorders. The paper was later fully-retracted due controversy surrounding the lead author, who had financial conflicts of interest and allegedly manipulated the study data. However, it generated worldwide concern over the safety of MMR and other types of vaccines, including Diphtheria/Tetanus/Pertussis (DTP).

In California by 2010, the growing trend for parents to opt out of having their children receive vaccines over the following decade coincided with the largest Pertussis outbreak in more than 60 years. Reduced vaccination frequency was also linked to a high-profile measles outbreak in 2014 that began at Disneyland. The resulting California state legislation (Senate Bill 277), signed June 2015, made it much more difficult for parents to opt out of vaccinations for their children. The data set will allow you to explore individual public and private school vaccination rates of incoming Kindergarten students for the 2000 to 2014 school years.

Content

The data are records for every school with ten or more students reporting the number of incoming Kindergarteners who provided either proof of immunization, personal beliefs exemption (PBE), or permanent medical exemption (PME). Annual records for the 2000-2001 through 2014-2015 school years have been formatted and combined. Common variables in these annual data sets included in the merged file are the number of students, school name, school county, the number of PBEs, PMEs, and number of students vaccinated for:

• Diphtheria/Tetanus/Pertussis (DTP)
• Polio
• Measles/Mumps/Rubella (MMR)

One additional file contains 5 years of county-level Pertussis case numbers and rates. Another additional data file contains the number of infant Pertussis cases for infants under three months old for each county in California between 2014-2015.

Geographic data are available in a file based on scripted geocode calls using the ggmap R package to find latitude and longitude data using the school names and county names. Not all calls returned a valid coordinate, so additional indicator variables in this file indicate the quality of the match. The isSchool indicator variable is 1 if the geocode search meta data included "school" and the countyMatch indicator is 1 if the latitude and longitude coordinates are contained within the appropriate county in CA.

References:

1. Retracted Lancet Research Article
2. Report on 2010 Pertussis Outbreak

Acknowledgements

Individual data files and detailed annual reports for every school year in this data set are provided by the California Department of Public Health (CDPH). Individual schools and licensed child care facilities are required to report immunization information to CDPH every year to maintain compliance with the California Health and Safety Code. Additional details as well as child care and 7th grade data files can be found on the CDPH website: https://www.cdph.ca.gov/programs/immunize/Pages/ImmunizationLevels.aspx

County level case data were pulled from the following report: https://archive.cdph.ca.gov/programs/immunize/Documents/Pertussis_Report_1-7-2015.pdf

Infant Pertussis data were reported to CDPH as of 2/10/2016. Additional Pertussis reports can be found here: https://www.cdph.ca.gov/programs/immunize/Pages/PertussisSummaryReports.aspx

Inspiration

While the Disneyland measles outbreak received much media attention, Pertussis outbreaks in California present great health risks to infants and the elderly. Can you predict which counties and schools are at greatest risk for outbreaks and/or quantify the association between vaccination rates and the number infant Pertussis cases?