The mechanism of increased susceptibility of Pneumococcal infection in patients with sickle cell anemia is:

Increased risk for pneumococcal infections Clinical Risk Group Examples Asplenia or splenic dysfunction Sickle cell disease, celiac disease Chronic respiratory disease Chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis, interstitial lung fibrosis, pneumoconiosis, bronchopulmonary dysplasia, aspiration risk, neuromuscular disease (e.g., cerebral palsy), severe asthma Chronic hea disease Ischemic hea disease, congenital hea disease, hypeension with cardiac complications, chronic hea failure Chronic kidney disease Nephrotic syndrome, chronic renal failure, renal transplantation Chronic liver disease Cirrhosis, biliary atresia, chronic hepatitis Diabetes mellitus Diabetes mellitus requiring insulin or oral hypoglycemic drugs Immunocompromise/immunosuppression HIV infection, common variable immunodeficiency, leukemia, lymphoma, Hodgkin's disease, multiple myeloma, generalized malignancy, chemotherapy, organ or bone marrow transplantation, systemic glucocoicoid treatment for >1 month at a dose equivalent to 20 mg/day (children, 1 mg/kg per day) Ref: Harisson, Edition - 18, Page 1154