Uptake of pneumococcal conjugate vaccine among children in the 1998-2002 United States birth cohorts.
BACKGROUND
Routine childhood immunization with pneumococcal conjugate vaccines (PCV7s) began in 2000 in the United States. Despite vaccine shortages, reductions in invasive pneumococcal disease occurred rapidly during 2000-2002. Age-appropriate PCV7 coverage was estimated and characteristics associated with undervaccination were identified for children in the 1998-2002 birth cohorts.


METHODS
Data were analyzed for 85,135 children aged 19-35 months in the 2001-2004 National Immunization Surveys. To obtain PCV7 coverage estimates by birth cohorts, a pooled analysis was conducted by combining individual survey years that sampled children with appropriate birth dates. Logistic regression models were used to identify factors associated with age-appropriate vaccination.


RESULTS
The proportion of children receiving the primary 3-dose PCV7 series by age 12 months increased from 45.5% (+/-0.6) among children born in 2000 to 62.1% (+/-0.7) among those born in 2002. By age 24 months, an estimated 30.7% (+/-0.6), 38.0% (+/-0.6), and 49.0% (+/-1.1) of children born in 2000, 2001 and 2002, respectively, had received all four PCV7 doses; however, only 15.0% (+/-0.4), 16.1% (+/-0.4) and 24.4% (+/-0.6) of children were age-appropriately immunized. Among children born in 1998 and 1999, 10.1% +/-0.5) and 37.6% (+/-0.7), respectively, received one or more catch-up doses during their second year of life. Lower age-appropriate PCV7 coverage was independently associated with black race, Hispanic ethnicity, receiving vaccinations from public health providers, and low household income.


CONCLUSIONS
The dramatic reductions in pneumococcal-related diseases from direct and indirect vaccine effects occurred when few children had received the recommended complete vaccine schedule, and there were substantial racial and socioeconomic disparities in coverage.
Nuorti
J Pekka
JP
National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. pnuorti@cdc.gov
Martin
Stacey W
SW
Smith
Philip J
PJ
Moran
John S
JS
Schwartz
Benjamin
B
D002675:Child, Preschool; D004363:Drug Utilization; D005191:Family Characteristics; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D008297:Male; D022401:Meningococcal Vaccines / Q000008:administration & dosage* / Q000600:supply & distribution; D011008:Pneumococcal Infections / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000600:supply & distribution; D012959:Socioeconomic Factors; D014481:United States; D018074:Vaccines, Conjugate
D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022401:Meningococcal Vaccines; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate