| Intervention type | Specific intervention (MAXO term suggestion where applicable) | Evidence level/source | Timing/indication | Key outcomes or efficacy data | Important notes/warnings |
|---|---|---|---|---|---|
| Vaccination | MenACWY conjugate vaccination (MAXO: meningococcal vaccination) | ESID/ERN RITA guideline; expert review; cohort practice data (pqac-00000016, pqac-00000004, pqac-00000007) | Recommended for all patients with terminal/late complement deficiency at diagnosis and continued with boosters | In the UK multicenter cohort, 39/40 patients (98%) received booster meningococcal vaccination after diagnosis; vaccination is considered a core prevention strategy and older expert teaching notes it may halve meningococcal disease risk, though breakthrough infection can still occur (pqac-00000007, pqac-00000002) | Must not be relied on as sole protection; terminal complement deficiency confers very high lifelong meningococcal risk despite vaccination. Booster schedules should follow current national guidance, which changes over time (pqac-00000016, pqac-00000002) |
| Vaccination | MenB vaccination (MAXO: meningococcal serogroup B vaccination) | ESID/ERN RITA guideline; recent case reports; expert review (pqac-00000016, pqac-00000003, pqac-00000013) | Recommended together with MenACWY for all patients with complement deficiency | Strongly recommended because serogroup B accounted for 43% of typed meningococcal infections in the UK terminal complement cohort (pqac-00000007); prevention-focused case management with ongoing vaccination was associated with 10-year infection-free follow-up in a C7-deficient patient (pqac-00000003) | Breakthrough disease remains possible; patient education about urgent assessment of fever is still necessary after full immunization (pqac-00000016, pqac-00000003) |
| Vaccination | Pneumococcal vaccination, preferably conjugate with booster strategy as indicated (MAXO: pneumococcal vaccination) | ESID/ERN RITA guideline; cohort practice data (pqac-00000016, pqac-00000007) | Recommended in complement deficiency, especially because invasive encapsulated bacterial infection risk is increased | Guideline emphasizes conjugate pneumococcal vaccination; in the UK cohort, 15% received an extra conjugate pneumococcal vaccine after diagnosis (pqac-00000007, pqac-00000016) | More strongly emphasized for broader complement defects such as C3 deficiency, but also appropriate in terminal deficiency because non-meningococcal invasive bacterial infections occur (pqac-00000016, pqac-00000007) |
| Vaccination | Haemophilus influenzae type b vaccination (MAXO: Haemophilus influenzae vaccination) | ESID/ERN RITA guideline (pqac-00000016) | Routine prevention in complement-deficient patients | Recommended as part of enhanced immunization against encapsulated bacteria (pqac-00000016) | Follow routine and catch-up schedules; no live-vaccine contraindication is noted for complement deficiency generally (pqac-00000016) |
| Antimicrobial prevention | Continuous antibiotic prophylaxis, typically penicillin/amoxicillin; macrolide alternative when appropriate (MAXO: prophylactic antibiotic therapy) | ESID/ERN RITA guideline; UK cohort; case report follow-up (pqac-00000016, pqac-00000004, pqac-00000007, pqac-00000003) | Consider for patients with recurrent infections, high exposure risk, or individualized high-risk profiles; often used after diagnosis | In the UK cohort, 70% were taking prophylactic antibiotics (pqac-00000004); a C7-deficient patient receiving ongoing azithromycin plus quadrivalent vaccination had no further meningitis over 10 years (pqac-00000003) | Adherence is a major limitation: 22% in the UK cohort admitted noncompliance (pqac-00000007). Balance benefit against antimicrobial resistance and tailor to local epidemiology/guidelines (pqac-00000016) |
| Antimicrobial prevention | Standby/emergency antibiotics for immediate use with urgent medical review (MAXO: emergency antibiotic therapy) | ESID/ERN RITA guideline (pqac-00000016) | For patients not on continuous prophylaxis, and also as part of emergency planning for all diagnosed patients | Intended to reduce delay to treatment of encapsulated bacterial infection; guideline recommends access to emergency antibiotics and prompt medical review (pqac-00000016) | Must be paired with explicit action plans; antibiotics do not replace urgent clinical assessment for suspected meningococcal disease (pqac-00000016) |
| Education / self-management | Patient and family education, emergency plan, medical alert identification (MAXO: patient education, emergency care planning) | ESID/ERN RITA guideline (pqac-00000016) | At diagnosis and reinforced annually | Guideline recommends annual follow-up to update education, vaccination, antibiotics, emergency advice, and family studies; MedicAlert-type identification is recommended to speed recognition in emergencies (pqac-00000016) | Essential because even vaccinated patients remain at risk for rapidly progressive infection; fever, rash, neck stiffness, or sepsis symptoms require urgent action (pqac-00000016) |
| Family-based prevention | Cascade/family screening, especially siblings (MAXO: genetic counseling, family member screening) | UK multicenter cohort; ESID/ERN RITA guideline (pqac-00000004, pqac-00000007, pqac-00000016) | At diagnosis of an index case and during follow-up | In the UK cohort, 52% were asymptomatic and diagnosed based on family history, and 80% had an affected family member (pqac-00000004). Screening therefore identifies high-risk but still healthy relatives before invasive infection occurs (pqac-00000007) | Particularly important in consanguineous families and autosomal recessive disease; asymptomatic status does not imply low future risk (pqac-00000004, pqac-00000007) |
| Monitoring / follow-up | Annual specialist immunology follow-up with review of vaccine status, adherence, infection history, and emergency planning (MAXO: clinical monitoring) | ESID/ERN RITA guideline (pqac-00000016) | Lifelong | Supports updating boosters, prophylaxis decisions, education, and family studies; helps maintain readiness for infection prevention (pqac-00000016) | Complement assays can be confounded by consumption during sepsis/autoimmunity; interpretation should consider clinical context (pqac-00000002, pqac-00000016) |
| Acute supportive management | Standard urgent treatment of invasive meningococcal infection/sepsis, including ICU care when needed (MAXO: intensive care management, antibacterial therapy) | Human cohort and case reports (pqac-00000004, pqac-00000007, pqac-00000003) | During acute infection | In the UK cohort, 22% required ICU for meningococcal septicemia (pqac-00000004); severe presentations including meningitis, septicemia, and arthritis occur despite prior unrecognized disease (pqac-00000003, pqac-00000007) | Disease can be fulminant; prevention does not eliminate need for rapid recognition and aggressive treatment (pqac-00000004, pqac-00000007) |
| Blood product replacement | Fresh frozen plasma in selected severe situations (MAXO: plasma transfusion) | Cohort/teaching evidence (pqac-00000007, pqac-00000002) | Rarely used in fulminant infection or special circumstances | Two patients in the UK cohort received FFP for fulminant meningococcemia (pqac-00000007) | Not standard long-term prevention; logistical limits and transfusion risks apply (pqac-00000002) |
| Counseling on therapeutic complement blockade | C5 inhibitor risk counseling for patients receiving eculizumab/ravulizumab or analogous terminal complement inhibitors (MAXO: medication risk counseling, meningococcal vaccination, prophylactic antibiotic therapy) | 2024 Lancet review; infection review; mechanistic/clinical literature (pqac-00000016) | Relevant when late complement deficiency is phenocopied by pharmacologic terminal complement inhibition | Terminal complement blockade markedly increases meningococcal susceptibility; patients on C5 inhibitors must receive meningococcal vaccines and have access to prophylactic antibiotics (pqac-00000016) | Important distinction: these drugs are treatments for complement overactivation disorders, not inherited terminal component deficiency itself. Vaccination and prophylaxis do not prevent all cases, so symptom vigilance remains necessary (pqac-00000016) |
| Public health / contacts | Vaccination of close contacts/household members (MAXO: contact vaccination) | ESID/ERN RITA guideline (pqac-00000016) | When a patient with complement deficiency is identified | Guideline recommends contacts also be vaccinated, adding a layer of indirect protection (pqac-00000016) | Does not substitute for direct patient immunization and prophylaxis (pqac-00000016) |


*Table: This table summarizes the main prevention and management interventions for late complement component deficiency, with emphasis on vaccination, antibiotic strategies, family screening, and emergency planning. It is useful for translating the literature into actionable clinical knowledge-base entries with ontology-ready intervention labels.*