Neisvac-C (N. Meningitidis Group C (Strain C11) Polysaccharide (De-O-Acetylated) Conjugated To Tetanus Toxoid)

Neisvac-C is a conjugate vaccine that targets the polysaccharide capsule of Neisseria meningitidis serogroup C, providing active immunity against meningococcal disease.

• Invasive meningococcal disease (serogroup C): reduces risk of severe infection, sepsis and meningitis.
• Nasopharyngeal carriage of serogroup C: helps lower bacterial carriage and transmission in the community.
• Travel to endemic regions: offers protection for individuals traveling to areas with documented serogroup C outbreaks.

• Neisvac-C contains the de‑O‑acetylated polysaccharide of Neisseria meningitidis group C chemically linked to tetanus toxoid. The conjugation converts the polysaccharide into a T‑cell‑dependent antigen, prompting the immune system to generate high‑affinity IgG antibodies against the capsular polysaccharide. These antibodies facilitate complement‑mediated bacterial lysis and opsonophagocytosis, establishing long‑lasting protective immunity against serogroup C strains. The immune memory generated enables rapid response upon subsequent exposure, contributing to herd immunity when coverage is high.

Following administration, Neisvac-C may be associated with local and systemic reactions, most of which are mild and transient.

Common Side Effects

• Injection site pain: mild soreness or tenderness at the injection site.
• Redness or swelling: localized erythema or edema around the injection area.
• Low‑grade fever: temperature rise up to 38 °C within 24 hours.
• Headache: mild to moderate headache occurring shortly after vaccination.
• Fatigue: transient tiredness or malaise lasting a day or two.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Guillain‑Barré syndrome: rare demyelinating neuropathy reported post‑vaccination.
• Seizures: infrequent febrile seizures in young children.
• Persistent high fever: fever >39 °C lasting more than 48 hours.
• Severe local reaction: extensive swelling or necrosis at the injection site.

Healthcare professionals should consider the following precautions when administering Neisvac-C.

• Contraindication: avoid use in individuals with documented severe allergic reaction to any vaccine component.
• Caution: defer vaccination in persons with acute moderate or severe illness until recovery.
• Immunocompromised patients: vaccine may elicit reduced antibody response; assess need for booster doses.
• Pregnancy: limited data; weigh potential benefits against unknown risks before vaccinating pregnant women.
• Age restrictions: not approved for use in infants younger than 2 months; follow local immunization schedule.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Vaccines can interact with other agents that affect the immune system or cause overlapping adverse events.

Major Interactions (Avoid)

• Live attenuated vaccines: avoid simultaneous administration; separate by at least 4 weeks.
• Blood products: postpone vaccination for 3 months after receipt of immunoglobulins or plasma.

Moderate Interactions (Monitor Closely)

• Immunosuppressive therapy: may diminish vaccine‑induced immunity; monitor antibody levels.
• Antipyretics: prophylactic use may mask fever, but does not affect immunogenicity.
• Antibiotics: generally no effect, but severe infections may delay vaccination.