What vaccines are recommended for patients with HbSS (Hemoglobin SS) sickle cell disease?

Vaccination and Assessment for Patients with HbSS Sickle Cell Disease

Patients with HbSS sickle cell disease require comprehensive pneumococcal, meningococcal, Haemophilus influenzae type b, and annual influenza vaccination due to functional asplenia, which places them at 20-30 times higher risk of invasive bacterial infections with mortality rates of 30-70%. 1, 2

Critical Pre-Vaccination Assessment Questions

Disease History and Complications

• Document history of invasive pneumococcal disease, acute chest syndrome, or pneumonia, as poor vaccine responders have significantly increased risk of recurrent pulmonary events (39% vs 10% in good responders) 3
• Assess for prior splenectomy or palpable spleen, as HbSS patients typically develop functional asplenia by age 2-5 years, though timing varies 1
• Review history of stroke or abnormal transcranial Doppler results, as silent cerebral infarcts are common in HbSS and may affect healthcare planning 1

Current Medications and Prophylaxis

• Confirm penicillin prophylaxis status: 125 mg orally twice daily starting by 2 months of age, increased to 250 mg twice daily at age 3, continued until at least age 5 or completion of pneumococcal vaccine series 1
• Document use of hydroxyurea or L-glutamine, as these may affect infection risk and vaccine response 1, 4

Vaccination History

• Obtain complete pneumococcal vaccination records including PCV13, PCV15, PCV20, and PPSV23 with specific dates and number of doses 1
• Document meningococcal vaccine history for both MenACWY and MenB serotypes 1, 2
• Verify Haemophilus influenzae type b completion and annual influenza vaccination status 1

Pneumococcal Vaccination Protocol

For Children Under 6 Years

Administer complete PCV series (PCV15 or PCV20 preferred) with catch-up dosing through 71 months of age. 1

For Children 6-18 Years Previously Vaccinated

• If at least one dose of PCV20 was received: No additional pneumococcal vaccines needed 1
• If only PCV13 or PCV15 received: Give one additional dose of PCV20 OR PPSV23 1

For Children 6-18 Years Never Vaccinated

Give single dose of PCV15 or PCV20; if PCV15 used, follow with PPSV23 at least 8 weeks later. 1, 2

For Adults (≥19 Years)

Administer PCV13 first, followed by PPSV23 at least 8 weeks later, with a second dose of PPSV23 five years after the first dose. 1, 2, 5 This prime-boost strategy improves breadth of antibody response, with 24.6% achieving response to 10-12 serotypes versus only 8% with PPSV23 alone 5

Critical pitfall: Despite vaccination, IPD incidence remains 29 times higher in children with HbSS compared to the general population, and after 2010, all IPD serotypes in HbSS patients were not covered by PCV13, emphasizing the importance of newer vaccines like PCV20. 4

Meningococcal Vaccination

Administer MenACWY vaccine at young age (starting at 2 months) with booster every 5 years for lifelong protection. 1, 2

Give MenB vaccine after age 10 years per recommendations for functional asplenia. 1 The 40-70% mortality rate from meningococcal infections in asplenic patients makes this vaccination critical 1, 2

Important timing consideration: Do not administer MCV4-D in patients under 2 years simultaneously with PCV due to reduced antibody response to pneumococcal serotypes 1

Haemophilus Influenzae Type B

Verify completion of primary Hib series by 6 months with booster at 6-8 months later, or single dose if vaccinated after 14 months of age. 1

For unvaccinated patients ≥5 years: Give one dose of Hib vaccine 1, 2

Annual Influenza Vaccination

Administer inactivated influenza vaccine (IIV) annually starting at 6 months of age. 1, 2

Never use live attenuated influenza vaccine (LAIV/nasal spray) in patients with functional asplenia. 1, 2

Additional Standard Vaccinations

Hepatitis B

Follow standard age-appropriate schedule; no special dosing required for HbSS patients without renal disease. 1

HPV Vaccine

Administer HPV vaccine series to patients aged 11-26 years per standard recommendations. 1

Tetanus/Diphtheria/Pertussis

Give DTaP for children under 7 years; Tdap for adolescents and adults per standard CDC schedule. 1

MMR and Varicella

Administer per standard schedule if not immunosuppressed; these live vaccines are generally safe in HbSS patients. 1

Post-Vaccination Monitoring

Consider measuring pneumococcal antibody titers 4-8 weeks after vaccination in high-risk patients with recurrent infections, as poor vaccine response predicts future acute chest syndrome (p=0.003) and pneumonia (p=0.036) 3

HbSS patients demonstrate poorer vaccine response than HbSC patients, with only 42% achieving good vaccine response versus 64% in HbSC, though this difference was not statistically significant 3

Patient and Family Education

Educate about lifelong infection risk and need for immediate medical attention for fever >101°F (38°C), as overwhelming post-splenectomy infection remains life-threatening despite vaccination 2

Reinforce daily home spleen palpation and recognition of splenic sequestration crisis 1

Emphasize continuation of penicillin prophylaxis even after vaccination completion, particularly in patients with history of invasive pneumococcal infection or surgical splenectomy 1