This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
23 serotypes pneumococcal vaccine Most useful in 
Select and explain. 
A. Cystic fibrosis, B. Recurrent otitis media & sinusitis, C. Child less than 2 years, D. Sickle cell anaemia
D: Sickle cell anaemia
Answer: D: Sickle cell anaemia 
Explanation: 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