4CMenB vaccine and its role in preventing transmission and inducing herd immunity

ABSTRACT

Introduction

Vaccination is the most effective method of protecting people from invasive meningococcal disease (IMD). Of all the capsular groups, B is the most common cause of invasive meningococcal disease in many parts of the world. Despite this, adolescent meningococcal B vaccine programs have not been implemented globally, partly due to the lack of evidence for herd immunity afforded by meningococcal B vaccines.

Areas covered

This review aims to synthesize the available evidence on recombinant 4 CMenB vaccines’ ability to reduce pharyngeal carriage and therefore provide indirect (herd) immunity against IMD.

Expert opinion

There is some evidence that the 4CMenB vaccine may induce cross-protection against non-B carriage of meningococci. However, the overall body of evidence does not support a clinically significant reduction in carriage of disease-associated or group B meningococci following 4CMenB vaccination. No additional cost-benefit from herd immunity effects should be included when modeling the cost-effectiveness of 4CMenB vaccine programs against group B IMD. 4CMenB immunization programs should focus on direct (individual) protection for groups at greatest risk of meningococcal disease. Future meningococcal B and combination vaccines being developed should consider the impact of the vaccine on carriage as part of their clinical evaluation.

KEYWORDS:

• Bexsero
• carriage
• herd protection
• herd immunity
• meningococcal
• Neisseria meningitidis
• 4cmenb

Article highlights

• Funded 4CMenB infant vaccine programs are now implemented in several countries. In adolescents, who are the key group to provide herd immunity, there have only been two large-scale government funded 4CMenB programs globally, partly due to uncertainty about the amount of herd immunity the 4CMenB vaccine provides.

• As recombinant meningococcal B vaccines are developed using different technologies than conjugate meningococcal vaccines, similar herd immunity to that observed following meningococcal A and C vaccination programs may not be replicated.

• Whilst there is some evidence that the 4CMenB vaccine may induce cross-protection against non-B carriage of meningococci, the overall evidence from three studies does not support a clinically significant reduction in disease-associated or group B pharyngeal carriage.

• At this stage, limited evidence is available to determine the effects of 4CMenB vaccination on reducing IMD in unvaccinated groups following large adolescent 4CMenB programs. Two studies with moderate vaccine uptake in adolescents found no reduction of group B IMD in unvaccinated age groups.

Acknowledgments

HM acknowledges support from NHMRC Practitioner fellowship 1155066.

Declaration of interest

H Marshall is an investigator on vaccine trials sponsored by Industry (the GSK group of companies, Novavax, Pfizer). H Marshall’s and M McMillan’s institution receives funding for investigator-led studies from Industry (Pfizer, the GSK group of companies). H Marshall and M McMillan receive no personal payments from Industry. P Richmond is an investigator on vaccine trials sponsored by Industry (the GSK group of companies, Novavax, Pfizer). P Richmond’s institution receives funding for investigator-led studies from Industry (Pfizer, the GSK group of companies, CSL). PR has been a member of scientific vaccine advisory boards for Industry (Pfizer, the GSK group of companies, Sanofi) but has not received any personal payments from Industry. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.