Click here for Nimenrix® (meningococcal groups A, C, W-135 and Y conjugate vaccine) Prescribing Information for Great Britain (GB) and Northern Ireland (NI). Click here for Trumenba®▼ (meningococcal group B vaccine (recombinant, adsorbed)) Prescribing Information for GB and NI.

Meningococcal disease refers to any illness caused by the bacterium Neisseria meningitidis.¹
N. meningitidis is only pathogenic (disease-causing) in humans.^{2​​​​​​​}

Ordinarily, antigens on the surface of bacteria are the target of immunological activity from the host immune system.³ In order to cause disease, N.meningitidis must survive in the bloodstream and avoid being killed by the innate immune mechanisms of the host, particularly the complement system.^{​​​​​​​3}

It is the structure of N. meningitidis that helps the bacterium to resist phagocytosis and complement-mediated lysis.⁴ The bacterium contains an outer membrane which is surrounded by a polysaccharide capsule.⁴

​​​​​​​The polysaccharide capsule partly acts as a protective shell to prevent binding of the complement system and resulting cleavage of C3 to C3b.² This cleavage would usually result in the effector functions of complement such as opsonisation which leads to phagocytosis.² Evasion can also be enhanced by other methods such as mimicry of host molecules and recruiting factor H.^{​​​​​​​2}

Figure 1: Polysaccharide capsule mechanism. Adapted from Tan LKK, Carlone GM, Borrow R. Advances in the development of vaccines against Neisseria meningitidis. N Engl J Med. 2010; 362:1511-20.⁵​​​​​​​

Meningococcal disease most commonly presents as meningitis and septicaemia.⁶

The incubation period of meningococcal disease is two to seven days.⁶ The rate at which the disease develops varies between patients.⁷ 

• The early symptoms (prodrome) could include fever, malaise, and lethargy.⁷
• The common symptoms of meningitis then could include neck stiffness, severe headache, and photophobia.⁷
• Comparatively, the common symptoms of sepsis could include limb/joint pain, pale/mottled blueish skin and tachycardia.⁷
• Both meningitis and sepsis may result in confusion, drowsiness, and impaired consciousness.^{​​​​​​​7}

Currently invasive meningococcal disease (IMD) incidence is below 1 per 100,000 in England.⁸

​​​​​​​The UK Health Security Agency Meningococcal Reference Unit confimed 205 cases in England between July 2021 and June 2022 (epidemiological year).^{​​​​​​​8}

In 1906, scientists began to recommend anti-meningococcal serum therapy to protect humans against meningococcal disease.⁹ This therapy was initially based on antibodies derived from the blood of horses. Later, the antibodies were derived from patients, or individuals recovering from meningococcal disease.⁹

​​​​​​​Antibiotics revolutionised treatment for meningitis however they do not always act fast enough to prevent damage that the bacteria can cause.⁹ The UK later introduced a conjugate vaccine against meningococcal disease with the MenC vaccine introduced in 1999.^{​​​​​​​9}