The Pneumocell-study: Vaccination of IgG1- and IgG2-deficient patients with Prevnar13

Abstract Background Patients with IgG-deficiency often suffer from repeated bacterial infections with S. pneumoniae. Since there is a lack of knowledge regarding whether IgG-deficient patients would benefit from conjugate pneumococcal vaccination, we set out to evaluate the effect of Prevnar13 vaccination in IgG 1 - and/or IgG 2 -deficient patients. Method We designed a small pilot-study including IgG 1 - and/or IgG 2 -deficient patients (n = 10) and age- and sex-matched healthy controls (n = 10). Serum, plasma and heparin-blood were collected prior to vaccination, as well as 1, 2 and 4 weeks post vaccination, and the levels of opsonophagocytic activity (Opa) titers and anti-pneumococcal IgG-antibodies were analyzed. Results Patients generally had lower Opa-titers than controls for most serotypes, but they exhibited an almost normal vaccine response to serotypes 6A and 6B. Notably, 5/10 patients showed vaccine-response to at least one serotype. Most patients reached the presumably protective levels of Opa-titers ≥8 and anti-pneumococcal IgG levels of 0.35 µg/ml by 4 weeks post-vaccination for a majority of the serotypes. Conclusion Our results show that vaccination of IgG-deficient patients with Prevnar13 is likely to have a clinical benefit. Our initial findings will provide a framework for future vaccine-trials in this vulnerable patient group. Registered at www.clinicaltrials.gov as NCT01847781 .