Meningococcal Polysaccharide Vaccine

Approved Indications:

• Active immunization against invasive meningococcal disease caused by Neisseria meningitidis serogroups A, C, W-135, and Y in individuals aged 2 years and older.
• Vaccination of individuals at increased risk, including:
• Travelers to endemic or epidemic regions (e.g., sub-Saharan Africa, Hajj pilgrimage)
• Military recruits
• People with functional or anatomical asplenia
• Individuals with persistent complement component deficiencies
• Laboratory personnel routinely exposed to N. meningitidis
• Residents of institutions or communities experiencing outbreaks

Clinically Accepted Off-Label Uses:

• Use during outbreaks for rapid mass immunization
• Booster vaccination in high-risk individuals when conjugate vaccines are contraindicated or unavailable
• Protection in adults over 55 years, where conjugate vaccines are not approved or accessible

Route of Administration: Subcutaneous (preferred); intramuscular injection is acceptable
Dosage Form: Lyophilized powder for reconstitution with a sterile diluent; single-dose vial (0.5 mL)

Recommended Dosage:

• Children (2–10 years): Single 0.5 mL dose
• Adolescents & Adults (11–55 years): Single 0.5 mL dose

Booster Doses:

• For individuals at continued risk (e.g., asplenia, complement deficiencies, travelers to endemic regions):
• Every 3 years for children under 5 years
• Every 5 years for individuals aged 5 years and older

Co-administration:

• Can be administered with other vaccines simultaneously at different injection sites using separate syringes

Meningococcal Polysaccharide Vaccine contains purified capsular polysaccharides from Neisseria meningitidis serogroups A, C, W-135, and Y. These polysaccharides act as T-cell–independent antigens, directly stimulating B lymphocytes to produce specific bactericidal antibodies. These antibodies target the polysaccharide capsule of the bacteria, facilitating complement-mediated lysis and opsonization, thereby preventing colonization and bloodstream invasion. Unlike conjugate vaccines, this T-cell–independent response does not generate immunologic memory or a strong booster effect, particularly in young children.

Pharmacokinetic parameters such as absorption, distribution, metabolism, and excretion (ADME) are not applicable to vaccines. However, the following immunologic characteristics apply:

• Onset of protection: Within 7–10 days of vaccination
• Peak antibody response: Achieved within 2–3 weeks
• Duration of immunity: Typically lasts 2–3 years; shorter in younger children
• Immunologic memory: Limited due to the absence of T-cell involvement

Pregnancy:

• FDA Pregnancy Category: C (traditional classification)
• Summary: No adequate human or animal studies are available. The vaccine should be used during pregnancy only if clearly needed and when the potential benefit outweighs the risk, especially in outbreak or high-risk situations.

Lactation:

• No data on excretion into human milk; however, due to the non-live nature of the vaccine, it is considered safe for use in breastfeeding mothers.
• No known adverse effects on the breastfed infant.

• Primary Class: Vaccine
• Subclass: Inactivated bacterial vaccine (Polysaccharide type)
• Target Pathogen: Neisseria meningitidis serogroups A, C, W-135, and Y

• Known hypersensitivity to any component of the vaccine
• Severe allergic reaction (e.g., anaphylaxis) to a previous dose of a meningococcal polysaccharide vaccine
• Acute febrile illness or severe infection (postpone vaccination until recovery)

• Reduced efficacy in children under 2 years due to poor immune response to polysaccharide antigens
• Limited duration of immunity and no booster effect—repeat doses may offer diminished response
• Use with caution in individuals with immunosuppression (e.g., cancer therapy, HIV)
• Syncope (fainting) can occur, especially in adolescents—observe patients for 15 minutes post-vaccination
• Some formulations may contain latex in vial components; use caution in individuals with latex allergy

Very Common to Common (≥1%):

• Local reactions: Pain, redness, swelling at injection site
• Systemic reactions: Fever, headache, fatigue, malaise, chills

Uncommon to Rare (<1%):

• Nausea, vomiting
• Rash, urticaria
• Myalgia, arthralgia

Serious Adverse Effects (Rare):

• Anaphylaxis
• Febrile seizures (mostly in children)
• Guillain-Barré Syndrome (very rare)

Onset: Most adverse events occur within 1–3 days of vaccination and are self-limiting

• Other vaccines: Can be co-administered with routine vaccines at separate injection sites
• Immunosuppressive therapy (e.g., corticosteroids, chemotherapy): May reduce antibody response
• CYP450 system: Not applicable; no interactions via liver enzyme pathways
• No known food or alcohol interactions

• CDC/ACIP: Polysaccharide vaccines are no longer preferred for routine use in adolescents; conjugate vaccines are now recommended due to superior immunogenicity and memory response.
• WHO: Polysaccharide vaccines remain acceptable in outbreak control and in adults ≥56 years when conjugate vaccines are not available.
• Programmatic shift: Many national immunization schedules have replaced polysaccharide vaccines with conjugate versions for long-term protection.
• Recommendation: Use polysaccharide vaccine only when conjugate alternatives are contraindicated or unavailable.

• Storage temperature: +2°C to +8°C (36°F to 46°F)
• Do not freeze: Freezing destroys vaccine potency
• Protect from light: Store in original carton until use
• Reconstitution instructions:
• Reconstitute with the supplied sterile diluent
• Use immediately after reconstitution
• Shake well before administration
• Handling: Discard if the solution is discolored or contains particles