Study of a Single Dose of a 21-valent Pneumococcal Conjugate Vaccine in Children and Adolescents With Sickle Cell Disease

Study Summary

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.