[Meningococcal vaccines. Global epidemiological situation and strategies for prevention by vaccination]

Meningococcal Group B Vaccine For The Prevention Of Invasive Meningococcal Disease Caused By Neisseria meningitidis Serogroup B

Invasive meningococcal disease (IMD) is a major public health concern because of its high case fatality, long-term morbidity, and potential to course with outbreaks. IMD caused by Nesseira meningitidis serogroup B has been predominant in different regions of the world like Europe and only recently broadly protective vaccines against B serogroup have become available. Two protein-based vaccines, namely 4CMenB (Bexsero®) and rLP2086 (Trumenba®) are currently licensed for use in different countries against MenB disease. These vaccines came from a novel technology on vaccine design (or antigen selection) using highly specific antigen targets identified through whole-genome sequence analysis. Moreover, it has the potential to confer protection against non-B meningococcus and against other Neisserial species such as gonococcus. Real-world data on the vaccine-use are rapidly accumulating from the UK and other countries which used the vaccine for control of outbreak or as part of routine immunization program, reiterating its safety and efficacy. Additional data on real-life effectiveness, long-term immunity, and eventual herd effects, including estimates on vaccine impact for cost-effectiveness assessment are further needed. Given the predominance of MenB in Europe and other parts of the world, these new vaccines are crucial for the prevention and public health control of the disease, and should be considered.

Natural resistance to Meningococcal Disease related to CFH loci: Meta-analysis of genome-wide association studies

Meningococcal disease (MD) remains an important infectious cause of life threatening infection in both industrialized and resource poor countries. Genetic factors influence both occurrence and severity of presentation, but the genes responsible are largely unknown. We performed a genome-wide association study (GWAS) examining 5,440,063 SNPs in 422 Spanish MD patients and 910 controls. We then performed a meta-analysis of the Spanish GWAS with GWAS data from the United Kingdom (combined cohorts: 897 cases and 5,613 controls; 4,898,259 SNPs). The meta-analysis identified strong evidence of association (P-value ≤ 5 × 10⁻⁸) in 20 variants located at the CFH gene. SNP rs193053835 showed the most significant protective effect (Odds Ratio (OR) = 0.62, 95% confidence interval (C.I.) = 0.52–0.73; P-value = 9.62 × 10⁻⁹). Five other variants had been previously reported to be associated with susceptibility to MD, including the missense SNP rs1065489 (OR = 0.64, 95% C.I.) = 0.55–0.76, P-value = 3.25 × 10⁻⁸). Theoretical predictions point to a functional effect of rs1065489, which may be directly responsible for protection against MD. Our study confirms the association of CFH with susceptibility to MD and strengthens the importance of this link in understanding pathogenesis of the disease.

Deciphering the Burden of Meningococcal Disease: Conventional and Under-recognized Elements

Invasive meningococcal disease remains a substantial global public health burden despite being vaccine-preventable worldwide. More than one million cases are reported annually, with average fatality rates ranging from 10% to 40% depending on clinical presentation and geographic location. Survivors may suffer debilitating sequelae that reduce the quality of life for the patient and family members responsible for their care. Major financial burdens are associated with acute treatment and follow-up care, and outbreak management often places extensive financial strains on public health resources. Although the clinical and financial aspects of meningococcal disease burden are straightforward to quantify, other burdens such as lifelong cognitive deficits, psychological stress, adaptive measures for reintegration into society, familial impact, and legal costs are systematically overlooked. These and other facets of disease burden are therefore not systematically considered in cost-effectiveness analyses that public health authorities take into consideration when making decisions regarding vaccination programs. Changing the approach for measuring meningococcal disease burden is necessary to accurately understand the societal consequences of this devastating illness. In this article, the conventional and under-recognized burdens of meningococcal disease are presented and discussed.

The Burden of Pediatric Invasive Meningococcal Disease in Spain (2008-2013)

BACKGROUND

Invasive meningococcal disease remains a rare infectious disease not only with high mortality but also with important morbidity. Until recently no universal vaccine existed against serogroup B, which explains most of the cases in settings like Europe. The objective of this study was to analyze the clinical course and sequelae of meningococcal disease in Spain.

METHODS

Retrospective review of all children younger than 15 years admitted to any of the 36 hospitals in the MENDICOS Spanish network (www.mendicos.org) with confirmed or probable invasive meningococcal disease in children between January 2008 and December 2013.

RESULTS

A total of 458 cases were identified across the country, most of them occurring in previously healthy children (91.5%; n = 419/458). Median (interquartile range) age was 1.7 (0.7 and 4.6) years, with 53.1% of the cases occurring in children younger than 2 years; 82.1% (n = 368) were laboratory confirmed cases; 95.2% (n = 256) of those serogrouped were serogroup B. The diagnosis was meningitis in 24.9% (n = 114) of the cases, sepsis in 37.1% (n = 170) and both in 38.0% (n = 174). Mean hospital length of stay was 11.6 (10.9) days; 79.2% (n = 354) of the patients required pediatric intensive care unit admission, with a mean pediatric intensive care unit stay of 3.9 (4.9) days; 3.5% (n = 16) died; 12.9% (n = 59) of the survivors were discharged with some kind of physical sequelae, mainly neurological (n = 23).

CONCLUSIONS

Serogroup B invasive meningococcal infection explains substantial morbidity and mortality in Spain, occurring mainly in infants. The recent availability of a vaccine against serogroup B may change this scenario. Given that the vast majority of the cases occur in otherwise healthy children, inclusion of the meningococcal B vaccine in the national immunization program should be carefully considered.

[Meningococcal C conjugate vaccine: Impact of a vaccination program and long-term effectiveness in Navarra, Spain, 2000-2014]

BACKGROUND

Since 2000, when the meningococcal serogroupC conjugate vaccine (MenCC) was introduced in the childhood immunization schedule in Spain, several changes in the schedule and catch-up campaigns have been performed. We aim to estimate the impact and effectiveness of this vaccine in Navarra up to 2014.

METHODS

The impact of the vaccination program was analysed by comparing incidence, mortality and lethality rates of disease before (1995-1999) and after (2004-2014) the introduction of the MenCC. Vaccine effectiveness was estimated using the screening method (Farrington) and the indirect cohort method (Broome). Data on cases were obtained from the active surveillance of meningococcal disease.

RESULTS

During 1995-1999 the mean annual incidence of meningococcalC disease was 1.32 per 100,000, and 7.18 per 100,000 in children younger than 15years. The fall of meningococcalC disease incidence was significant in cohorts targeted for vaccination from the beginning and progressive in the general population. No cases were reported between 2011 and 2014. The estimated vaccine effectiveness was 96% by the screening method, and 99% by the indirect cohort method.

CONCLUSION

The MenCC vaccination program has been successful in decreasing the incidence rate of serogroupC meningococcal disease in Navarra, and schedule changes have maintained high vaccine effectiveness throughout the study period.