What is the recommended vaccination and prophylaxis regimen for a patient who underwent splenectomy with unknown vaccination status?

Post-Splenectomy Vaccination and Prophylaxis Protocol for Unknown Vaccination Status

All patients with prior splenectomy and unknown vaccination status should receive a complete vaccination series immediately, starting with PCV20 (or PCV15 followed by PPSV23), both meningococcal vaccines (MenACWY and MenB), Haemophilus influenzae type b (Hib), and annual influenza vaccine, along with lifelong antibiotic prophylaxis. 1, 2

Core Vaccination Requirements

Pneumococcal Vaccination

• Administer PCV20 as the preferred initial pneumococcal vaccine (or PCV15 if PCV20 unavailable) 1, 2
• If using PCV15, follow with PPSV23 at least 8 weeks later 1, 2
• Revaccinate with PPSV23 every 5 years for life to maintain protection as antibody levels wane over time 1, 3
• The 23-valent polysaccharide vaccine is more than 90% effective in healthy adults under age 55 4

Meningococcal Vaccination

• Administer both MenACWY and MenB vaccines—this is non-negotiable given the 40-70% mortality rate from meningococcal infections in asplenic patients 1, 2
• Give MenACWY as a 2-dose primary series, 8 weeks apart 1, 2
• Revaccinate with MenACWY every 5 years for life 1, 2, 3
• Administer MenB as either a 2-dose or 3-dose series depending on formulation 1, 2
• Revaccinate with MenB every 2-3 years if risk remains 1, 2

Haemophilus influenzae Type b (Hib)

• Give one single dose of Hib vaccine for previously unvaccinated adults 1, 2, 3
• No revaccination needed if the patient completed childhood Hib series 1

Annual Influenza Vaccination

• Administer annual inactivated or recombinant influenza vaccine for life to all patients over 6 months of age 1, 2, 3
• This reduces the risk of secondary bacterial infections that can be catastrophic in asplenic patients 1

Critical Timing Considerations

Since the splenectomy has already occurred and vaccination status is unknown:

• Administer all vaccines immediately once the patient is identified 1, 2
• All vaccines can be given simultaneously at different injection sites 4
• The 14-day post-operative window is only relevant for recent splenectomy; for remote splenectomy, vaccinate without delay 2, 5

Lifelong Antibiotic Prophylaxis

Daily Prophylaxis

• Offer lifelong prophylactic phenoxymethylpenicillin (penicillin V) to all post-splenectomy patients 4, 1, 3
• Highest priority in the first 2 years post-splenectomy when risk peaks 4, 1
• For penicillin-allergic patients, use erythromycin 4

Emergency Standby Antibiotics

• Provide amoxicillin for home use with explicit instructions to take immediately at the first sign of fever >101°F (38°C), malaise, or chills 1, 2, 3
• This is potentially life-saving as most OPSI deaths occur within 24-48 hours of symptom onset 1, 2

Patient Education and Documentation

Critical Information to Convey

• Educate patients about lifelong increased infection risk—the risk persists for decades, with cases reported more than 20 years post-splenectomy 4, 1, 3
• Overwhelming post-splenectomy infection (OPSI) carries 30-70% mortality, with Streptococcus pneumoniae accounting for approximately 50% of cases 1, 2, 3
• Instruct patients to seek immediate emergency department evaluation for any fever, as fulminant sepsis can progress to death within 24 hours 1, 2

Medical Alert and Provider Notification

• Issue medical alert identification (card or bracelet) indicating asplenic status 1, 3
• Formally notify the patient's primary care provider of asplenic status to ensure appropriate ongoing care 1, 2
• Provide written information about OPSI risk 4, 1

Special Precautions

Animal Bites

• After dog or animal bites, asplenic patients require a 5-day course of co-amoxiclav due to susceptibility to Capnocytophaga canimorsus 4, 1, 2

Travel Considerations

• Malaria prophylaxis is essential for travelers to endemic areas 4, 1

Immunosuppression Considerations

• If the patient received rituximab in the previous 6 months, vaccine response may be suboptimal 1, 3
• Reassess vaccination once B-cell recovery has occurred 1, 3

Common Pitfalls to Avoid

Do Not Delay Vaccination

• Never postpone vaccination while trying to obtain old records—assume unvaccinated status and proceed immediately 4, 1
• There is no harm in revaccinating someone who may have received vaccines previously 4

Do Not Forget Lifelong Revaccination

• The single most common failure is not scheduling booster vaccines 6, 7, 8
• Studies show only 4.2% of splenectomized patients receive appropriate meningococcal boosters 7
• Set up a tracking system to ensure patients return for PPSV23 every 5 years and MenACWY every 5 years 1, 3

Do Not Underestimate the Risk

• Even with optimal vaccination, protection is not 100%—patients remain at elevated risk for life 4
• At least 28% of post-splenectomy invasive bacterial infections could have been prevented with proper vaccination 7
• Two children died from pneumococcal infection 5 and 8 years after splenectomy when not taking prophylactic penicillin and not vaccinated 9

Quality of Evidence Considerations

The strongest evidence comes from multiple high-quality guidelines 1, 2, 3 that synthesize recommendations from the CDC, American College of Surgeons, American College of Physicians, and Infectious Diseases Society of America. These consistently recommend the vaccination and prophylaxis protocol outlined above. Older guidelines 4 support the same core principles but with older vaccine formulations. Research studies 7, 8 demonstrate alarmingly poor adherence to these guidelines in real-world practice, with vaccination coverage ranging from only 18.7% to 55.1% depending on the vaccine, underscoring the critical importance of systematic implementation.