This article is more than 5 years old. Information may no longer be current.
IgG levels among preterm infants contingent on Prevnar 13 schedules
A reduced primary schedule for the Prevnar 13 vaccine yielded higher post-booster immunoglobulin G concentrations in premature babies, but the best schedule to follow would be when patients faced their greatest risk for disease, according to study findings.
“Premature infants are at increased risk of vaccine-preventable diseases, including a twofold risk of invasive pneumococcal disease compared with term infants,” Alison Kent, MBChB, MRCPCH, professor in the pediatric infectious disease research group and vaccine institute at St. George’s, University of London, and colleagues wrote. “In most industrialized countries with established pneumococcal immunization programs, the 13-valent pneumococcal conjugate vaccine [Prevnar 13, Pfizer; PCV 13] has superseded the 7-valent pneumococcal conjugate vaccine (PCV7) and has been shown to be highly immunogenic in term infants.”
In a phase 4, multicenter, open-label, 1-year randomized controlled trial, the researchers examined 210 preterm babies for immunogenicity based on reduced (2 and 4 months), accelerated (2, 3 and 4 months) and extended (2, 4 and 6 months) doses of PCV13 schedules. All patients also received a 12-month booster after the primary series. The researchers measured serotype-specific pneumococcal immunoglobulin G (IgG) for PCV13 serotypes with enzyme-linked immunosorbent assay 1 month after the booster administrations.
They determined that 75% of babies in the reduced schedule group (95% CI, 62-85), 88% on the accelerated schedule (95% CI, 76-95) and 97% on the extended schedule (95% CI, 87-99) had protective antibody concentrations for no less than 50% of the PCV13 serotypes. In addition, the majority of patients had seroprotective IgG concentrations regardless of vaccination schedule. The analysis showed, however, that participants in the extended schedule group had lower geometric mean protective antibody concentrations (P < .05) vs. reduced (for nine serotypes) and accelerated (for four serotypes) schedules after the booster and primary PCV13 series vaccinations.
The researchers recommended that physicians who vaccinate premature infants with PCV13 use the current data as a reference for their immunization programs and epidemiologic schedules.
“Our results indicate that most preterm infants can achieve seroprotective antibody concentrations for the serotypes in PCV13 regardless of the primary schedule administered, especially after the 12-month booster, but the magnitude of their immunologic response is dependent on the primary schedule they receive,” Kent and colleagues wrote. – by Kate Sherrer
Disclosure: Kent reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.
