Study Shows PCV13 Followed by PPSV23 Protects Against Pneumococcal Diseases in Patients With SCD

Immunization with the 13-valent conjugate pneumococcal vaccine (PCV13) prior to the 23-valent polysaccharide vaccine (PPSV23) was found to protect against pneumococcal disease by enhancing the antibody response across a wide variety of pneumococcal serotypes in adult patients with sickle cell disease (SCD), according to a study published in Clinical Infectious Diseases.

The study authors noted that patients with SCD have a high risk for invasive pneumococcal diseases. They added that the immunological efficacy of PCV13 followed by PPSV23 has been poorly documented in adult patients with SCD.

The open-label, phase 2 study (NCT02274415) was conducted between 2013 and 2017 at Henri Mondor Hospital in France. The trial randomized 128 patients to receive PPSV23 at week 4 either with or without PCV13 at baseline.

The investigators sought to analyze safety and humoral immunity through week 96 with a primary endpoint of the total amount of patients who had a 4-fold increase in serotype-specific immunoglobulin (Ig)G antibody levels to at least 10 pneumococcal serotypes between baseline and week 8. The investigators used a modified intention-to-treat population defined as those administered at least 1 vaccine dose for the primary efficacy analysis.

The proportion of responders (4-fold increase of serotype-specific IgG antibodies) to at least 10-shared serotypes was assessed at week 8. Secondary endpoints in the trial included geometrical mean titers (GMTs), responders to 0-1, 2-5, 6-9, and 10-12 serotypes, pneumococcal opsonophagocytic (OPA) activity, and response durability at weeks 24 and 96.

The mean age of individuals administered either PCV13 plus PPSV23 (n=63) or PPSV23 alone (n=65) was 39.2±10.6 and 38.7±10.3 years, respectively. Further, 54.0% and 50.8% were women, 68.2% and 72.3% had hemoglobin SS SCD, 23.8% and 23.1% had hemoglobin SC SCD, and 98.4% and 98.4% had anemia, respectively.

A significantly greater percentage of those in the PCV13 plus PPSV23 versus PPSV23 alone cohorts showed a 2-fold increase in antibody titers to at least 10 pneumococcal serotypes at weeks 8 (47.4% vs 19.7%; P <.001), 24 (41.7% vs 23.6%; P =.050), and 96 (38.7% vs 13.5%; P =.017). Further, a significantly greater number of patients in the PCV13 plus PPSV23 versus PPSV23 alone cohort showed a 4-hold increase in antibody titers to at least 10 serotypes at week 8 (24.6% vs 8.2%; P =.016).

The data show that administration of PCV13 plus PPSV23 compared with PPSV23 alone produced improved antibody responses to 0 to 1 (15.8% vs 52.5%), 2 to 5 (35.1% vs 31.1%), 6 to 9 (24.6% vs 8.2%), and 10 to 12 (24.6% vs 8.2%) pneumococcal serotypes.

“A PCV13/PPSV23 regimen improved the breadth and magnitude of antibody responses against a large range of pneumococcal serotypes in adults with SCD,” the study authors concluded. “The sustainability of the immune response requires recall strategies.”

Reference

Giovanna Melica, Pablo Bartolucci, Etienne Audureau, Philippe Le Corvoisier, Anoosha Habibi, Justine Gellen, Dalia Selmane, Marc Michel, Christine Lacabaratz, Yves Levy, Immunological efficacy of pneumococcal vaccination including the 13-valent pneumococcal vaccine in adult patients with sickle-cell disease: results of the randomized DREVAC controlled trial, Clinical Infectious Diseases, 2023;, ciad037, https://doi.org/10.1093/cid/ciad037. Accessed March 6, 2023.