New vaccine offers hope of beating epidemic meningitis by 2030

A trial of a new vaccine against meningococcal disease, a cause of meningitis and blood poisoning, has been found to be safe and induces a strong immune response against five strains of meningococcal bacteria: A, C, W, Y and X.

The phase 3 trial compared the immune response generated by the new pentavalent vaccine NmCV-5 to that of the licensed quadrivalent vaccine MenACWY-D in 1,800 healthy young people aged 2 to 29 years in Mali and The Gambia.

After 28 days, at all ages, immune responses generated by a single dose of NmCV-5 were generally higher than those generated by MenACWY-D.

In addition, NmCV-5 induced a strong immune response against the emerging strain of meningococcus X for which there is currently no licensed vaccine.

The trial revealed no safety issues with NmCV-5.

The study, led by a team including researchers from the Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene & Tropical Medicine (LSHTM), and researchers from Bamako in Mali, is published in the New England Journal of Medical.

The World Health Organization (WHO) estimates that meningitis caused 250,000 deaths in 2019 and developing affordable vaccines that provide broad coverage against meningococcal strains is a key part of its global roadmap to Defeat Meningitis in 2030.

Supply and accessibility issues have limited the use of quadrivalent meningococcal vaccines in the “meningitis belt,” a part of sub-Saharan Africa at high risk for meningococcal and pneumococcal meningitis epidemics. Additionally, meningococcus X has emerged with the potential to cause epidemics in the ‘meningitis belt’, so there is an urgent need to find a vaccine against this strain.

Building on the success of the Meningitis Vaccine Project (which developed MenAfriVac, a meningococcal A vaccine), the Serum Institute of India and PATH developed NmCV-5 with the goal of eliminating meningococcal disease in sub-Saharan Africa.

More cost-effective production methods should mean that NmCV-5 can be made available at a lower cost than existing quadrivalent vaccines, overcoming a major barrier to its wide availability in the ‘meningitis belt’. The trial was designed to provide the WHO with the evidence needed to license the new vaccine for future outbreak control.

Dr Ed Clarke, pediatrician in the Gambia MRC Unit Vaccines and Immunity at LSHTM and co-author, said: “We are delighted with the results of this study. We expect NmCV-5 to provide protection against meningitis caused by meningococcal bacteria in children and young adults. The new vaccine will be a critical tool to interrupt and prevent devastating meningitis epidemics in the meningitis belt. We hope that it will help achieve the goal of overcoming epidemic meningitis by 2030, set out in the global roadmap, becomes a reality.”

Meningitis is a deadly disease with the ability to spread like wildfire in an outbreak, it affects all ages, especially in the meningitis belt region.

Epidemic preparedness is the way forward to provide available, affordable and accessible vaccines suitable for areas prone to meningitis epidemics. Having vaccines against meningitis should be a public health priority to prevent catastrophic consequences during an epidemic and would be a game-changer in the fight against meningitis.

As a researcher on the continent, it is my hope that relevant vaccines for common strains in the meningitis belt region will be readily available for timely interventions through collaboration and teamwork of multi-center trials like ours. Together we can beat meningitis.”

Dr Ama Umesi, co-author of MRC Unit The Gambia at LSHTM

Vaccinations for the trial took place in June 2021. The 1,800 participants were divided into three age groups: 2-10 years old, 11-17 years old, 18-29 years old. All participants were African and 50.7% of participants were women.