Ans-D. Sickle cell anaemia* PPSV23 (Pneumovax or Pnu-Immune) is the most widely available formulation and contains 23 pneumococcal polysaccharides* A single dose of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) is indicated for adults (ages 19 to 64 years)* Vaccination with both PCV13 and PPSV23 is indicated in individuals with impaired splenic function for eg- Sickle cell disease or other hemoglobinopathy