Pharmacology · Bacterial and antimalarial vaccines
Meningococcal vaccine !
Conjugate vaccines against serogroups A, C, W and Y, and protein vaccines against B. They prevent meningococcal meningitis and sepsis.
Updated 2026-11-01
Also called: MenACWY conjugate vaccine, Meningococcal B vaccine (MenB), Pentavalent conjugate vaccine
Mechanism of action
Conjugate vaccines link each serogroup's capsular polysaccharide to a carrier protein and give a T-dependent response with memory. The serogroup B capsule resembles human molecules, so its vaccines use surface proteins instead. Antibodies activate complement, which kills the bacterium; that is why complement deficiency raises risk so much.
- Vaccine supplies conjugated capsules (A, C, W, Y) or proteins (B)
- Bactericidal antibodies and memory form
- Antibodies activate complement, which lyses meningococci
- Less nasopharyngeal carriage and transmission
Pharmacokinetics
- Onset and duration
- Protection is serogroup-specific and kept up with boosters in risk groups
Indications
- Prevention of meningococcal meningitis in adolescents, travellers to endemic areas and during outbreaks Bacterial meningitis →
- Prevention of invasive disease in asplenia, complement deficiency or complement-inhibitor treatment Sepsis and septic shock →
Adverse effects
Common
- Local pain and redness
- Headache, fatigue, muscle pain and irritability
Contraindications
- Previous anaphylaxis to a component or a dose
- For MenACWY conjugate: anaphylaxis to diphtheria toxoid, tetanus toxoid or CRM197 vaccines when that is the carrier protein
Key interactions
- Complement inhibitors (eculizumab, ravulizumab)
- They greatly raise the risk of meningococcal disease; vaccination is part of their safe use
What is monitored
- Risk conditions: asplenia, complement deficiency, HIV, laboratory work with N. meningitidis
- Serogroups covered by the product given
Administration and safety
- Intramuscular route
- MenB vaccines are not interchangeable: the series is completed with the same product
- Check the serogroups the product covers
Nursing care
- Identify risk groups (asplenia, complement, travellers)
- Watch for local reaction and mild general symptoms
- Teach warning signs: fever with petechiae, neck stiffness
Pregnancy and breastfeeding
Not part of routine vaccination in pregnancy.
Test yourself
Think of the answer, then tap the question to see it.
Why does meningococcal B vaccine use proteins instead of the capsule?
The serogroup B capsule resembles the body's own molecules and is poorly immunogenic; surface proteins do induce bactericidal antibodies.
Which treatment greatly increases the risk of meningococcal disease?
Complement inhibitors such as eculizumab or ravulizumab, because complement is key to killing meningococci.
What do close contacts of a meningococcal case receive, besides vaccine in outbreaks?
Prophylactic antibiotics to clear the bacterium from the nasopharynx and reduce transmission.
Related drugs
Related conditions
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Chapter 14: Meningococcal Disease | Pink Book | CDC (Centers for Disease Control and Prevention, 2021); Meningitis (World Health Organization, 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025).
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