Date of Award

January 2014

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)


School of Public Health

First Advisor

Daniel M. Weinberger

Second Advisor

Melinda M. Pettigrew



Streptococcus pneumoniae is an important human pathogen with more than 92 identified serotypes of varying invasiveness. Asymptomatic colonization of the nasopharynx can later cause diseases such as sinusitis, AOM, or IPD. Children under age five are the major reservoirs of infection. Pediatric conjugate vaccines effectively reduce vaccine-type carriage and disease. Vaccinating children can have indirect effects on adults.

Materials and Methods:

This paper used CIRTS to describe patterns of three- and four-dose PCV uptake throughout Connecticut in 2000 to 2009 birth cohorts. Spatial cluster analysis was used to detect any clusters with higher than expected proportions of unvaccinated children. Log-binomial regression models were used to assess unadjusted and adjusted associations between variables from the 2000 U.S. Census and proportions of unvaccinated children in ZCTAs. These factors describe the racial and socioeconomic composition, age distribution, population density, and housing characteristics of ZCTAs.


There were 315,628 children across 266 ZCTAs in the registry. Across all cohorts and ZCTAs, 91 percent of children received three doses of PCV and 74 percent received all four doses. Vaccination rates varied across cohorts and by poverty level. Cluster analysis revealed several significant clusters. All selected community-level variables were independently associated with a high proportion of unvaccinated children in ZCTAs. All but three variables comprise a final multivariate model.


Connecticut enjoys a robust uptake of both three and four doses of PCV. Areas near Groton, New Haven, and parts of Windham, Tolland, Hartford, and New London counties would benefit from increased vaccine delivery efforts. Socioeconomic variables were consistently related to risk of ZCTAs having a high proportion of unvaccinated children.

Abbreviations Used:

AIC= Akaike information criterion

APIC=Advisory Committee on Immunization Practices

AOM=acute otitis media

CDC=Centers for Disease Control and Prevention

CIRTS=Connecticut Immunization Registry and Tracking System

HMO=health maintenance organization

IAP=Immunization Action Plan

IPD=invasive pneumococcal disease


PCP=primary care physician

PCV=pneumococcal conjugate vaccine

PCV7=heptavalent pneumococcal vaccine

PCV13=13-valent pneumococcal conjugate vaccine

PPV23=23-valent plain polysaccharide vaccine

RR=relative risk

CHIP=Children's Health Insurance Program

UFFS=unassigned fee-for-service

VFC=Vaccines for Children

VT=vaccine type

ZCTA=zip code tabulation area


This is an Open Access Thesis.

Open Access

This Article is Open Access