Meningitis vaccine successfully induces immune response against five bacterial strains

The results of the phase 3 vaccine trial were recently announced and published in the journal New England Journal of Medicine. 

The trial, conducted in 2021, included 1,800 people (aged two to 29) in Mali and the Gambia. After 28 days, the immune responses induced by a single dose of this new vaccine were found to be greater than those generated by MenACWY-D shots. The findings demonstrated that the vaccine boosted immune protection against all five strains of meningococcal bacteria, which causes meningitis A, C, W, Y, and X.

“We are excited about the results of this study. We expect NmCV-5 to provide children and young adults with reliable protection against meningitis caused by meningococcal bacteria,” said Dr. Ed Clarke, a pediatrician from the Vaccines and Immunity Theme at MRC Unit The Gambia at LSHTM and co-author of this study.

Meningitis epidemics have occurred in many parts of the world, according to the World Health Organization (WHO), but the disease most commonly affects 26 countries in Sub-Saharan Africa, forming the meningitis belt. As per WHO, this disease claimed the lives of approximately 25,000 people in 2019.

“Epidemic preparedness is the way forward in providing available, affordable, and accessible vaccines relevant to regions prone to meningitis outbreaks. Having meningitis vaccines should be a public health priority to prevent catastrophic outcomes during an outbreak and would be a game changer in the fight against meningitis,” said Dr. Ama Umesi, co-author from MRC Unit The Gambia at LSHTM, in an official release. 

The low-cost vaccine could be useful in controlling its spread in African countries such as Senegal, Mali, and Ethiopia. The team hopes this development will help to achieve the goal of eradicating meningitis by 2030.

The study is led by 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. 

Study abstract:

An effective, affordable, multivalent meningococcal conjugate vaccine is needed to prevent epidemic meningitis in the African meningitis belt. Data on the safety and immunogenicity of NmCV-5, a pentavalent vaccine targeting the A, C, W, Y, and X serogroups, have been limited.

Methods: We conducted a phase 3, noninferiority trial involving healthy 2-to-29-year-olds in Mali and Gambia. Participants were randomly assigned in a 2:1 ratio to receive a single intramuscular dose of NmCV-5 or the quadrivalent vaccine MenACWY-D. Immunogenicity was assessed at day 28. The noninferiority of NmCV-5 to MenACWY-D was assessed on the basis of the difference in the percentage of participants with a seroresponse (defined as prespecified changes in titer; margin, lower limit of the 96% confidence interval [CI] above −10 percentage points) or geometric mean titer (GMT) ratios (margin, lower limit of the 98.98% CI >0.5). Serogroup X responses in the NmCV-5 group were compared with the lowest response among the MenACWY-D serogroups. Safety was also assessed.