Vaccine-induced protection against hepatitis B in pediatric solid organ transplant patients

Vaccination against hepatitis B virus (HBV) has led to a worldwide reduction in disease burden and mortality. Vaccine immunogenicity data in transplanted children are limited, and vaccine-induced protection may be reduced. We evaluated HBV vaccination coverage, seroprotection rates, and factors influencing vaccine immunity among pediatric solid organ transplant (SOT) patients.

We retrospectively identified patients ≤21 years of age evaluated for SOT and/or transplanted at our center between January 1, 2015, and December 31, 2018. A detailed chart review was conducted using a standard questionnaire to gather information on demographic, clinical, and laboratory features of patients' HBV vaccination, and hepatitis B surface antibody (HBsAb) titers.

A total of 381 patients undergoing evaluation and/or transplantation were included: 139 (36.5%) liver, 138 (36.2%) kidney, and 104 (27.3%) heart. Overall, HBsAb at evaluation was reactive in 216 (56.7%), indeterminate in 17 (4.5%), non-reactive in 138 (36.2%), and not available in 10 (2.6%). Of those that completed a primary HBV vaccine series (n = 304), HBsAb was reactive in 164 (53.9%), indeterminate in 13 (4.3%), non-reactive in 119 (39.1%), and not available in 8 (2.6%). For those up to date for age on HBV vaccinations with non-reactive/indeterminate titers at evaluation, revaccination and a follow-up HBsAb were available in 45 patients of which 33 (73.3%) seroconverted to a reactive HBsAb titer.

Vaccine-induced protection against HBV infection among high-risk pediatric SOT recipients can be improved by serology-based intervention. Though the absence of HBsAb does not always indicate loss of protection, boosting or completing primary series is recommended.