Four dose hepatitis B vaccination among children aged 19-35 months—National Immunization Survey, 2010

Background: U.S. infants typically receive 3 doses of hepatitis B (HepB) vaccine to protect against infection. When HepB-containing combination vaccines became available in the late 1990s, 4 doses of HepB were permitted when 3 doses followed a monovalent birth-dose. Because detection of hepatitis B vaccine-induced antibody might be greater among infants who receive >3 doses of HepB, we assessed the proportion U.S. infants who received ≥4 doses. Methods: We analyzed data from the 2010 National Immunization Survey for children aged 19-35 months to determine the weighted proportion of children who received ≥4 doses of HepB vaccine. Multivariate logistic regression was used to determine characteristics associated with receipt of a birth dose plus ≥3 doses of combination vaccine. Results: Of 17,004 children surveyed, 30.1% received ≥4 doses of hepatitis B vaccine, of whom 68.5% received a birth dose and ≥3 doses of combination vaccine. Provider-related characteristics associated with receipt of a birth dose and ≥3 doses of combination vaccine included children with ≥3 vaccination providers (aOR 2.1, 95% CI 1.3-3.2, one provider as referent) and children who received vaccination exclusively from public or hospital providers (private providers as referent) (aOR: 1.5, 1.2-1.9, and aOR: 1.7, 1.4-2.1, respectively). Non-Hispanic black (aOR 0.75, 0.60-0.93) and multiple race children (aOR 0.73, 0.60-0.90) had lower odds of receiving a birth dose and ≥3 doses of combination vaccine compared with non-Hispanic white children. Conclusions: A sizable minority of children received ≥4 doses of HepB. Investigation is needed to determine the effect of an additional dose on long-term protection against infection.