There has been quite of bit of discussion among our infectious disease colleagues and neonatologists as to how best to vaccinate preterm infants who have been noted to have a higher risk of invasive pneumococcal disease. Three priming schedules have been utilized nationally including a reduced schedule of only two doses at 2 and 4 months chronologic age, an accelerated schedule at 2,3, and 4 months of chronologic age or the usual extended schedule of 2,4, and 6 months of age.
Kent et al. (peds.2015-3945) opted to look at which of these schedules shows the best immunogenicity after priming and after a booster is given when the infant is 12 months of age. Using serotype-specific pneumococcal IgG for the 13 serotype pneumococcal-conjugate vaccine (PCV 13), to no surprise the best priming to the serotypes in PCV13 was in the extended schedule and least effective was in the reduced schedule (although even there 75% of infants had protection to at least half the vaccine serotypes). What is most interesting is that the reduced schedule infants showed the most improvement in IgG concentrations after the one year booster compared to the other schedules.
So which schedule is best for which preterm infant? Infectious disease specialists Drs. Mark Sawyer and Mobeen Rathore (peds.2016-0975) take a shot at helping us decide based on what age a particular preterm infant with particular health issues may be most at risk for pneumococcal infection (e.g. in early infancy or after they enter toddlerhood). To better understand why the findings are what they are in this study and what it means for your preterm patients, read both the article and commentary and see if the findings change how you immunize the preterm infants in your practice.
