A Phase 2 interventional study of Prevenar13 (PCV13) and Pneumovax (PPS23) and Placebo / Pneumovax (PPS23) in Splenectomised Patients, sponsored by Assistance Publique - Hôpitaux de Paris. Completed at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-01.
Sponsored by Assistance Publique - Hôpitaux de Paris · Phase 2, Interventional, and Prevention
This research is a multi-center French randomized and double blind phase IIb clinical trial evaluating 2 revaccination strategies against pneumococcal infections among splenectomised patients. The main objective is to evaluate at M13 the immunological response of 2 pneumococcal revaccination strategies (combined revaccination by a boost dose of PCV13 following 12 months later by PPS23, versus PPS23 alone) in splenectomised adults.
For the prevention of invasive pneumococcal diseases, two polysaccharide vaccines are currently available: a non-conjugate vaccine, Pneumovax® (PPS23), and a conjugate vaccine, Prevenar13® (PCV13), inducing protection against 23 and 13 pneumococcal serotypes, respectively. The PPS23 is considered weakly immunogenic, especially in infants, elderly and immunocompromised patients, while PCV13 is now available for adults. In France, in April 2017, the new recommendations for at risk patients including asplenic patients are to revaccinate by PPS23 at least five years after the previous PPS23. However a phenomenon of vaccine hyporesponsiveness and a risk of immune tolerance to pneumococcus after repeated administrations of PPS23 are described. Large doses of polysaccharide antigens recruit memory and naive B cells, resulting in the production of low and high avidity antibodies, while low doses only stimulate memory B cells, inducing high affinity antibodies. Because of that, Swiss current recommendations are to revaccinate with PCV13 at 5 years the splenectomised patients. The recommendations of revaccination by PPS23 for USA or PCV13 for Switzerland have never been evaluated in clinical trial. Moreover, using combined PCV13/PPS23 could increase serotype coverage. Studying the immune response following combined revaccination by a boost dose of PCV13 following by PPS23 versus PPS23 alone will help to document and improve the vaccine recommendations.
The main objective is to evaluate at M13 the immunological response of 2 pneumococcal revaccination strategies (combined revaccination by a boost dose of PCV13 following 12 months later by PPS23, versus PPS23 alone), in splenectomised adults.
The primary endpoint is the proportion of patients responding to a minimum of 5 of the 9 serotypes analysed (9 serotypes among the 12 common serotypes to both PPS23 and PCV13: 1, 3, 6B, 7F, 9V, 14, 19A, 19F, and 23F) at M13 in each arm. A responder to a serotype is defined as a four-fold increase of the rate of OPA (OpsonoPhagocytic Assay) compared to baseline and titer ≥ LLOQ (Lower Limit of Quantification).
281 studies on the registry are indexed under Pneumococcal Infections; 27 are open to participants now.
This study's enrollment of 39 is below the median of 379 across 230 interventional studies indexed under Pneumococcal Infections.
Browse Pneumococcal Infections studies →Assistance Publique - Hôpitaux de Paris is the lead sponsor of 3,505 studies on the registry; 1,006 are open to participants now.
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Exclusion Criteria:
Prime-boost strategy combining a single dose of 13-valent pneumococcal conjugate vaccine (Prevenar 13, PCV13) at month 0 (M0) followed by a single dose of 23-valent unconjugated vaccine (Pneumovax, PPS23) at month 12 (M12).
Biological: Prevenar13 (PCV13) and Pneumovax (PPS23) · Biological: Blood sample
Standard strategy combining a single dose of placebo vaccine (Prevenar 13 placebo) at month 0 (M0) followed by a single dose of 23-valent unconjugated vaccine (Pneumovax, PPS23) at month 12 (M12)
Biological: Placebo / Pneumovax (PPS23) · Biological: Blood sample
One dose of PCV13 at Month 0 and one dose of PPS23 at Month 12
One dose of Placebo at Month 0 and one dose of PPS23 at Month 12
an additional 5 mL sample of blood at one of the visits, preferably at the first visit, concerning patients included in Parisian centers who did not participate in SPLENEVAC 1 study.
Immunogenicity
Immune response at M13 against minimum of 5 of the 9 serotypes analysed (9 serotypes among the 12 common serotypes to both PPS23 and PCV13: 1, 3, 6B, 7F, 9V, 14, 19A, 19F, and 23F) in each arm. A responder to a serotype is defined as a four-fold increase of the rate of OpsonoPhagocytic Assay (OPA) compared to baseline (M0) and titer ≥ Lower Limit of Quantification (LLOQ).
Time frame: at Month 13
Enzyme-linked immunosorbent assay (ELISA) antibody dosages
ELISA antibody concentration against 9 common serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F), and, the proportion of positive serotypes: serotype is considered positive if the immunoglobulin G (IgG) antibody concentration in ELISA shows a two-fold increase from baseline (M0) in each arm from baseline.
Time frame: Month 0 to Month 24
Enzyme-linked immunosorbent assay (ELISA) antibody dosages
ELISA antibody concentration against 9 common serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F), and, the proportion of positive serotypes: serotype is considered positive if the IgG antibody concentration is ≥ 1μg/ml in each arm from baseline.
Time frame: Month 0 to Month 24
Enzyme-linked immunosorbent assay (ELISA) antibody dosages
ELISA antibody concentration against 9 common serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F), and, the proportion of positive serotypes: serotype is considered positive if the IgG antibody concentration shows a two-fold increase from baseline (M0) in each arm and IgG ≥ 1μg/ml from baseline.
Time frame: Month 0 to Month 24
Titration of OPA -
OPA titers against 9 common serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F) and the proportion of positive serotype: serotype is considered positive if the antibody titer shows a four-fold increase from baseline (M0).
Time frame: at Month 0, Month 13 and Month 24
Titration of OPA -
OPA titers against 9 common serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F) and the proportion of positive serotype: serotype is considered positive if the antibody titer ≥ LLOQ.
Time frame: at Month 0, Month 13 and Month 24
Titration of OPA -
OPA titers against 9 common serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F) and the proportion of positive serotype: serotype is considered positive if the antibody titer shows a four-fold increase from baseline (M0) and titer ≥ LLOQ.
Time frame: at Month 0, Month 13 and Month 24
ELISA antibody dosages
ELISA antibody concentration against 3 uncommon specific serotypes of PPS23 (12F, 10A and15B) and the proportion of positive serotypes: serotype is considered positive if the IgG antibody concentration shows a two-fold increase from baseline (M12) in each arm and IgG ≥ 1 μg/ml
Time frame: at Month 12, Month 13 and Month 24
ELISA antibody dosages
ELISA antibody concentration against 3 uncommon specific serotypes of PPS23 (12F, 10A and 15B) and the proportion of positive serotypes: serotype is considered positive if the IgG antibody concentration shows a two-fold increase from baseline (M12) in each arm.
Time frame: at Month 12, Month 13 and Month 24
ELISA antibody dosages
ELISA antibody concentration against 3 uncommon specific serotypes of PPS23 (12F, 10A and 15B) and the proportion of positive serotypes: serotype is considered positive if the IgG antibody concentration in ELISA is ≥ 1μg/ml in each arm.
Time frame: at Month 12, Month 13 and Month 24
Sustainability and evolution of the immune response
Measure of ELISA concentration and OPA titers for the 9 PCV13 serotypes in each arm.
Time frame: at Month 0 and Month 24
ELISA antibody dosages
ELISA antibody concentration against 9 common specific serotypes (1, 3, 6B, 7F, 9V, 14, 19A, 19F and 23F) and the proportion of positive serotype: serotype is considered positive if the IgG antibody concentration in ELISA and shows a two-fold increase from baseline (M0) in each arm in SPLENEVAC 1
Time frame: at Month 3
Percentage of patients presenting local or systemic reactions post-immunization
Number of subjects with local and systemic reactions following vaccinations (tolerability) in each arm.
Time frame: Month0 to Month 24
Plan to share: No
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Assistance Publique - Hôpitaux de Paris