The purpose of this study is to measure whether PCV21 vaccine (investigational pneumococcal vaccine) is safe and can help the body to develop germ-fighting agents called "antibodies" (immunogenicity) compared with 20vPCV (licensed pneumococcal vaccine) when given as a single dose to children aged 2 to 17 years with sickle cell disease who had received or not a previous vaccination with pneumococcal conjugate or pneumococcal polysaccharide vaccine.
Aged 2 to 17 years on the day of inclusion.
Participants who have a documented diagnosis of sickle cell disease (SCD) in their medical record.
Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be pre-menarchal or surgically sterile. OR
Is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 4 weeks after study intervention administration. A participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 25 hours before the study intervention.
Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy.
History of microbiologically confirmed S. pneumoniae infection or disease.
History of seizure or significant stable or progressive neurological disorders such as inflammatory nervous system diseases, encephalopathy, and cerebral palsy.
Known systemic hypersensitivity to any of the study interventions components, or history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances.
Parallel
PCV21
Biological/VaccineInvestigational pneumococcal conjugate vaccine
20vPCV
Biological/Vaccine20-valent pneumococcal conjugate vaccine
Number of participants reporting immediate adverse events (AEs)
Unsolicited (spontaneously reported) systemic AEs after injection of a pneumococcal vaccine
Number of participants reporting solicited injection site and solicited systemic reactions
Number of participants reporting unsolicited (spontaneously reported) injection site reactions and unsolicited systemic AEs after injection of a pneumococcal vaccine
Number of participants reporting serious adverse events (SAEs) and adverse events of special interest (AESIs)
SAEs and AESIs are collected throughout the study period
Number of participants with serotype-specific IgG concentrations for all serotypes included in PCV21
Ab concentrations for each pneumococcal serotype are measured by ECL assay
Number of participants with serotype specific opsonophagocytic activity (OPA) titers for all serotypes included in PCV21
Serotype specific OPA titers for each pneumococcal serotype are determined by multiplex opsonophagocytic killing assay (MOPA)
Number of participants with serotype specific opsonophagocytic activity (OPA) titers for all serotypes included in PCV21
Serotype specific OPA titers for each pneumococcal serotype are determined by multiplex opsonophagocytic killing assay (MOPA)