Immunogenicity of Pneumococcal Vaccines Examined in Children With SLE

The use of sequential 13-valent and 23-valent pneumococcal vaccines (PCVs) achieves protective status in approximately two-thirds of patients with pediatric systemic lupus erythematosus (SLE). Lack of response may be secondary to inherent or induced functional impairments in this population, according to the results of a prospective, observational study published in Lupus.

The investigators sought to examine the immunogenicity of PCVs in a cohort of sequential children with SLE. They hypothesized a suboptimal pneumococcal vaccine response in these patients. The children were assessed in a clinic setting where they were receiving vaccinations as part of a quality improvement project and current standard of care.

A total of 26 patients were enrolled in the study between 2016 and 2018. All of the participants had received the standard childhood PCV7 vaccination at 2, 4, and 6 months of age, followed by an additional dose at 12 to 16 months of age. Patients with either newly diagnosed SLE or preexisting disease who were <19 years of age at the time of their first clinic vaccination participated in the study.

All patients had baseline pneumococcal laboratory assessment performed for antibody levels against 23 serotypes of Streptococcus pneumoniae. Participants then received the PCV13 immunization, with follow-up pneumococcal antibody levels evaluated 4 to 8 weeks later. After 8 to 32 weeks, patients received the unconjugated 23-valent pneumococcal polysaccharide (PPSV23) immunization. Pneumococcal antibody levels were obtained 4 to 8 weeks after the second vaccine.

Of 26 participants, approximately 65% attained >70% vaccinated serotype antibody levels of >1.3 mcg/dL following receipt of PCV13. Of 22 participants who were followed through PPSV23 vaccination, 59% achieved the same response. Participants with rituximab exposure in the 6 months prior to being vaccinated were more likely not to achieve protective serotype levels (P <.01 for PCV13; trend P =.07 for PPSV23). Nonresponders to PCV13 generally also did not respond to PPSV23. In contrast, retrospective healthy controls attained 100% protective levels in response to PPSV23 immunization, with 95% of the serotypes >1.3 mcg/dL.

Taking into consideration the variability in the definition of “protective” serotype concentrations, the investigators concluded that a study that evaluates the clinical efficacy of vaccines among patients with SLE and correlates with serotype concentrations may be warranted before changes in vaccine strategy are implemented in this patient population.

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Reference

Gorelik M, Elizalde A, Wong Williams K, Gonzalez E, Cole JL. Immunogenicity of sequential 13-valent conjugated and 23-valent unconjugated pneumococcal vaccines in a population of children with lupus [published online October 31, 2018]. Lupus. doi:10.1177/0961203318808589