Meningococcal vaccine found to be safe and effective for infants in sub-Saharan Africa

University of Maryland School of Medicine (UMSOM) researchers helped conduct an important new global health study that found a vaccine that protects against five strains of meningitis prevalent in sub-Saharan Africa is safe and effective for use in young children beginning at 9 months of age.

This study provided evidence that formed the basis for the World Health Organization’s (WHO) decision last year to recommend the pentavalent Men5CV meningitis vaccine for infants ages 9 months and older.

Results of the study were published today in the journal Lancet.

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In January 2024, the WHO recommended that all countries in the African meningitis belt introduce Men5CV into their routine immunization programs, providing a single-dose shot to infants and young children ages 9 to 18 months. Previous data supported use of this vaccine starting at age 1, but there was no data on whether the vaccine could be given as part of the routine vaccination schedule for infants or whether it should be given on a separate occasion, requiring an additional medical encounter. 

Reassuring evidence

Receiving WHO approval could lead to a monumental shift in the burden of meningitis in susceptible parts of Africa. 

“This critical clinical study provides reassuring evidence that this pentavalent vaccine can be safely and effectively given along with other routine immunizations, which makes it far easier to curtail invasive meningococcal disease and potentially save tens of thousands of lives,” said Wilbur Chen, MD, MS, the Frank M. Calia, MD Endowed Professor of Medicine at UMSOM’s Center for Vaccine Development and Global Health (CVD) and protocol chair for this study.

The African meningitis belt is a region of 26 countries in sub-Saharan Africa where the rate of incidence of meningitis is very high. It includes Mali, where this study was conducted, and extends from Senegal to Ethiopia. Death rates from meningitis can surpass 15 percent in this region due to lack of healthcare access to medical care. Long-term complications like brain damage or paralysis occur twice as frequently compared to more developed countries.  

Because of the rapid onset of invasive bacterial meningitis and difficulties in accessing care in the African meningitis belt, prevention by vaccination is the optimal way to reduce meningitis cases.

Usual culprit

The primary cause of meningitis in the belt is Neisseria meningitidis. At present, the WHO has prequalified only one vaccine, Men5CV, that protects against the five most prevalent subtypes of N. meningitidis: serogroups A, C, W, X, and Y.

During six months of 2022, more than 1,300 children were enrolled in the study conducted in Mali and randomly assigned to receive a meningitis vaccine at either 9 months or 15 months of age. Infants randomized to the 9-month age group were then further randomized in a 2:1 ratio to receive a single dose of the investigational meningococcal vaccine Men5CV (brand name MenFive®, manufactured by Serum Institute of India Pvt. Ltd.) or a single dose of the comparator meningococcal vaccine (MenACWY-TT, Nimenrix), which protects against only 4 of the 5 serogroups. The results of the trial involving 9-month-old infants found Men5CV is proven to protect against meningococcal serogroups A, C, W, X, and Y.

“Demonstrating that this vaccine is safe and immunogenic in infants is a critical step in providing a broadly effective tool for preventing epidemics of severe illness and death in the swath of Africa known as the meningitis belt,” said Karen Kotloff, MD, Professor of Pediatrics at UMSOM who is also the Associate Director for Clinical Research and Principal Investigator of the Vaccine and Treatment Evaluation Unit (VTEU) at CVD. “Men5CV can be stored at room temperature for up to 12 weeks and is affordable for African countries.”

Collaborative effort

Researchers at the VTEU conducted the study in partnership with the Center for Vaccine Development-Mali (CVD-Mali). The VTEU at CVD is part of a national program known as the Infectious Diseases Clinical Research Consortium (IDCRC).  The IDCRC is funded by the National Institute of Allergy and Infectious Diseases to provide a ready resource for conducting clinical trials of vaccines and treatments for infectious diseases.

Milagritos Tapia, MD, Professor of Pediatrics at UMSOM, and Samba Sow, MD, MS, Director General of the CVD-Mali and Adjunct Professor of Medicine at the UMSOM were Co-Principal Investigators on the study.

The international global health organization PATH provided support for the study design and managed and funded the serology testing.

“The development of affordable, effective vaccines that are designed for use in Africa have been a game-changer for meningitis belt countries and are instrumental for global efforts to defeat meningitis by 2030,” said Bill Hausdorff, PhD, director of PATH’s meningitis vaccine development projects. “PATH is proud to have contributed to this essential study that helped lower the age limit for Men5CV and enable its inclusion in routine immunization programs—ensuring widespread protection from meningococcal disease is possible and epidemics become a thing of the past.”

Academic medicine partnerships

PATH also previously supported development of the investigational vaccine through a 13-year collaboration with SIIPL, leading to its licensure and subsequent prequalification by WHO.

“This study underscores the importance of academic medicine partnerships with world class global health entities like PATH,” said Mark T. Gladwin, MD, who is the John Z. and Akiko K. Bowers Distinguished Professor and Dean of University of Maryland School of Medicine. “After widespread use of the MenAfrivac vaccine, meningococcal A disease has been virtually eliminated from the African meningitis belt, and now, with the Men5CV vaccine, we see the potential to end meningococcal disease epidemics caused by other predominant serogroups.” 

The IDCRC, in partnership with the National Institute of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health, conducted this study. The research was supported by NIAID cooperative agreement UM1AI148689.