Long-lasting hyporesponsivenss induced by the 23-valent pneumococcal polysaccharide vaccine (PPV23) in asplenic patients with β-thalassemia major

Our findings suggest that PPV23 should be used cautiously in asplenic adults vaccinated with multiple PPV23s in the past. Measurement of anti-pneumococcal antibodies before and after vaccination could be used to optimise timing of vaccinations and certify vaccine immunogenicity in such individuals.