The everchanging epidemiology of meningococcal disease worldwide and the potential for prevention through vaccination

Abstract

Neisseria meningitidis is a major cause of bacterial meningitis and septicaemia worldwide and is associated with high case fatality rates and serious lifelong complications among survivors. Twelve serogroups are recognised, of which six (A, B, C, W, X and Y) are responsible for nearly all cases of invasive meningococcal disease (IMD). The incidence of IMD and responsible serogroups vary widely both geographically and over time. For the first time, effective vaccines against all these serogroups are available or nearing licensure. Over the past two decades, IMD incidence has been declining across most parts of the world through a combination of successful meningococcal immunisation programmes and secular trends. The introduction of meningococcal C conjugate vaccines in the early 20 0 0s was associated with rapid declines in meningococcal C disease, whilst implementation of a meningococcal A conjugate vaccine across the African meningitis belt led to near-elimination of meningococcal A disease. Consequently, other serogroups have become more important causes of IMD. In particular, the emergence of a hypervirulent meningococcal group W clone has led many countries to shift from monovalent meningococcal C to quadrivalent ACWY conjugate vaccines in their national immunisation programmes. Additionally, the recent licensure of two protein-based, broad-spectrum meningococcal B vaccines finally provides protection against the most common group responsible for childhood IMD across Europe and Australia. This review describes global IMD epidemiology across each continent and trends over time, the serogroups responsible for IMD, the impact of meningococcal immunisation programmes and future needs to eliminate this devastating disease.

Mass gatherings: a review of the scope for meningococcal vaccination in the Indian context

“…48 The relatively young age of the general population in India is another factor to be taken into account, given the peak in IMD incidence in the adolescent/young adult age group. 7,62 Since IMD is a vaccine-preventable disease, 73 these risk factors could be addressed with routine meningococcal vaccination but currently however, only vaccination during an outbreak, and vaccination of certain high-risk groups, students studying abroad, and travelers to the Hajj and sub-Saharan Africa, are sponsored by the Indian government. 63,64,71 The decision to not include meningococcal vaccination in the EPI is based on a perceived low burden of IMD 64 but, as already discussed, there is a lack of accurate data on its epidemiology.…”

“…The IAP recommends conjugate vaccines rather than polysaccharide-only meningococcal vaccines because polysaccharide-only vaccines are T cell-independent and so are only effective for short-term protection in children older than 2 years and adults. 69 , 71 Conjugate vaccines elicit longer-term protection from birth and induce immune memory 72 , 73 and may prevent the acquisition of meningococcal carriage. 73 A polysaccharide bivalent (serogroups AC) vaccine and polysaccharide or conjugate quadrivalent (ACWY) vaccines are licensed against IMD in India.…”

“…69 , 71 Conjugate vaccines elicit longer-term protection from birth and induce immune memory 72 , 73 and may prevent the acquisition of meningococcal carriage. 73 A polysaccharide bivalent (serogroups AC) vaccine and polysaccharide or conjugate quadrivalent (ACWY) vaccines are licensed against IMD in India. Polysaccharide vaccines are used most widely via the EPI or where vaccination is mandatory, while conjugate vaccines are more commonly used in the private sector.…”

Review of clinical studies comparing meningococcal serogroup C immune responses induced by MenACWY-TT and monovalent serogroup C vaccines

“…The distribution of meningococcal serogroups causing disease varies geographically and over time. 27 Therefore, to ensure adequate protection against IMD, national vaccination strategies have adapted to temporal changes in epidemiology. This is exemplified by the experience with the introduction of MenC vaccination programs.…”

4CMenB Immunization Induces Serum Bactericidal Antibodies Against Non-Serogroup B Meningococcal Strains in Adolescents

“…The vaccine is licensed for use against MenB-caused IMD in individuals 10-25 years of age in the USA and from 2 months of age in Europe and several countries worldwide. Men-FHbp is a bivalent fHbp vaccine licensed in individuals 10--25 years of age in the USA and from 10 years of age in Europe [7]. The UK was the first country to implement a vaccination program against MenB in 2015 using 4CMenB, with an already noticeable impact on MenB-caused IMD incidence [8].…”