What vaccinations are recommended for children after undergoing a splenectomy (removal of the spleen)?

Post-Splenectomy Vaccination for Children

All children undergoing splenectomy must receive vaccinations against encapsulated bacteria—specifically pneumococcal, meningococcal (both MenACWY and MenB), Haemophilus influenzae type b, and annual influenza vaccines—to prevent overwhelming post-splenectomy infection (OPSI), which carries a 30-70% mortality rate. 1, 2

Core Required Vaccinations

Pneumococcal Vaccines

• Administer PCV20 (preferred) or PCV15 as the initial pneumococcal vaccine, followed by PPSV23 at 6-12 weeks later (minimum 8-week interval). 3, 2
• Children require revaccination with PPSV23 every 5 years for life. 2
• The conjugated pneumococcal vaccine (PCV) is particularly important for children as it generates superior IgG memory B cell responses compared to polysaccharide vaccines alone. 4
• Children under 2 years should receive reimmunization after 2 years due to inherently reduced antibody response. 5, 2

Meningococcal Vaccines

• Both MenACWY and MenB vaccines are required—this is not optional. 3, 2
• Administer MenACWY as a 2-dose primary series, 8 weeks apart. 3
• Give MenB vaccine (either 2-dose or 3-dose series depending on formulation). 3
• Revaccinate with MenACWY every 5 years for life, and with MenB every 2-3 years if risk remains. 2
• Meningococcal infection carries 40-70% mortality in asplenic patients. 2

Haemophilus influenzae Type b (Hib)

• Administer one dose of Hib conjugate vaccine if not previously vaccinated or if vaccination status is incomplete. 1, 3, 2
• The conjugate Hib vaccine produces significantly higher antibody levels (geometric mean 48,106 ng/mL) compared to polysaccharide vaccines (10,786 ng/mL). 6
• Nearly all splenectomized children under age 10 are already protected through routine childhood immunization programs. 7

Influenza Vaccine

• Annual inactivated or recombinant influenza vaccine is mandatory for life for all children over 6 months of age. 1, 5, 2
• This reduces secondary bacterial pneumonia and sepsis risk by 54%. 2
• Prevention of influenza decreases the risk of secondary pneumococcal infection. 1

Critical Timing Considerations

For Elective Splenectomy

• Ideally, administer all vaccines at least 2 weeks (minimum 14 days) before surgery to ensure optimal antibody response. 1, 3, 2
• If scheduling permits, vaccinate 4-6 weeks before surgery for optimal immune response. 3, 2
• Adequate antibody formation typically requires 9 days. 3

For Emergency/Traumatic Splenectomy

• Wait at least 14 days post-operatively before vaccinating, as antibody response is suboptimal before this timeframe. 1, 3, 2
• In children discharged before 15 days where the risk of missing vaccination is high, vaccinate before discharge despite suboptimal timing. 1

Critical Vaccine Interaction to Avoid

Do not use MCV4-D (meningococcal vaccine) before completing all PCV13 doses in children under 2 years with asplenia, as simultaneous administration reduces antibody response to certain pneumococcal serotypes. 3 Use MCV4-CRM instead for this age group. 3

Children at Highest Risk

• Children under 5 years—especially infants—have an infection rate exceeding 10%, much higher than adults (<1%). 2
• Asplenic children younger than 5 years have greater overall risk of OPSI with increased mortality compared to adults. 1
• The risk exceeds 30% in neonates. 1
• Children with sickle cell disease (HbSS, HbSC) are at especially high risk. 2

Lifelong Risk Profile

• The risk of OPSI is lifelong and clinically significant, with cases reported more than 20 years after splenectomy. 5, 2
• Most infections occur within the first 2 years, but up to one-third manifest at least 5 years later. 5, 2
• The incidence of OPSI is 0.5-2%, with mortality rates of 30-70%, and most deaths occur within the first 24 hours. 1, 3
• Streptococcus pneumoniae accounts for approximately 50% of OPSI cases. 1, 3

Additional Protective Measures Beyond Vaccination

Antibiotic Prophylaxis

• Lifelong prophylactic antibiotics should be offered to all children, with highest priority in the first 2 years post-splenectomy. 3, 2
• Prophylactic oral phenoxymethylpenicillin is the standard agent. 2
• Some experts recommend at least 2 years of prophylactic antibiotics, though duration remains controversial. 1
• For children, continue prophylaxis for at least 5 years. 8

Emergency Standby Antibiotics

• Provide emergency standby antibiotics (amoxicillin) for home use at first sign of fever >101°F (38°C), malaise, or chills. 3, 2
• Recommended starting dose: Amoxicillin 3g followed by 1g every 8 hours. 1
• This is especially critical when medical review is not readily accessible. 1, 2

Patient and Provider Education

• Provide written information about lifelong infection risk and issue a medical alert card indicating asplenic status. 2
• Primary care providers must be formally notified of the child's asplenic status to ensure appropriate ongoing care. 1, 3, 2
• Only 8% of appropriate immunizations are completed in some studies due to lack of coordination. 2

Common Pitfalls to Avoid

• Failing to administer both MenACWY and MenB vaccines—both are required. 2
• Forgetting lifelong revaccination schedules—protection wanes and infection risk persists for life. 2
• Vaccinating too soon after emergency splenectomy—wait at least 14 days for optimal antibody response. 1, 3, 2
• Not providing emergency standby antibiotics—children need immediate access to antibiotics at home. 2
• Real-world compliance is poor: only 26-29% of asplenic patients receive all recommended vaccines. 9, 7
• At least 28% of post-splenectomy infections could have been prevented with proper vaccination. 7

Special Consideration: Conjugate vs. Polysaccharide Vaccines

Conjugated vaccines are superior for children because spleen removal eliminates IgM and IgG memory B cells against polysaccharide antigens, but conjugated vaccines can restore the pool of anti-pneumococcal IgG memory B cells even after splenectomy. 4 This is why PCV (conjugate) must be given before PPSV23 (polysaccharide). 3, 2