Meningitis shot that fights 5 different strains shows promise in latest trial

Meningococcal bacteria under a microscope. According to the World Health Organization, meningitis caused an estimated 25,000 deaths in 2019.

According to the World Health Organization, meningitis caused an estimated 25,000 deaths in 2019. European Centre for Disease Prevention and Control

A phase 3 trial found that a new meningococcal disease vaccine is safe and effective and also induces a strong immune response across five strains of meningococcal bacteria. The results were published May 24 in the New England Journal of Medicine. The vaccine could be a useful tool in eliminating meningitis in African countries including parts of Senegal, Mali, and Ethiopia.

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Meningococcal disease is a cause of meningitis and blood poisoning. According to the World Health Organization, meningitis caused an estimated 25,000 deaths in 2019. While vaccines are readily available in wealthier countries, vaccinating the more vulnerable regions has been a challenge, largely due to cost. Developing affordable vaccines that provide broad coverage against meningococcal disease strains is a key part of the World Health Organization’s Defeating Meningitis by 2030 Global Roadmap.

The trial compared the immune response generated by a new pentavalent, or 5-in-1, vaccine  called NmCV-5 against that of the licensed quadrivalent, or 4-in-1, MenACWY-D vaccine. The participants included 1,800 healthy two to 29-year-olds in Mali and The Gambia in western Africa. The vaccinations occurred in June 2021, and the trial didn’t find any safety concerns with NmCV-5. 

After 28 days, the immune responses generated by one dose of NmCV-5 were generally higher than those generated by the 4-in-1 vaccine across all age groups. The 5-in-1 vaccine also induced a strong immune response across meningococcal bacteria strains A, C, W, and Y and the emerging X strain. Currently, there is no licensed vaccine against the X strain, which may be the cause of meningitis epidemics in sub-Saharan Africa.

“Meningitis is a deadly disease with the ability to spread like wildfire in the event of an outbreak, this affects all ages most especially within the meningitis belt region,” study co-author Ama Umesi said in a statement. Umesi is a clinical trial coordinator and clinician from the Medical Research Council’s Unit The Gambia at the London School of Hygiene & Tropical Medicine. 

“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,” Umensi said.

Issues with supply and affordability have limited the use of 4-in-1 meningococcal vaccines across a portion of sub-Saharan Africa called the meningitis belt. This region is at high-risk of epidemics of both meningococcal and pneumococcal meningitis. The NmCV-5 vaccine was developed by the Serum Institute of India and PATH, the global division of the Bill & Melinda Gates foundation. It follows the successful Meningitis Vaccine Project that developed an effective meningococcal A vaccine called MenAfriVac.

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According to the study, the new NmCV-5 vaccine can be made available at lower cost than existing 4-in-1 vaccines with more cost-effective production methods. The trial was designed to provide the World Health Organization with the evidence it needs to license the new vaccine for future epidemic control.

“As a researcher in the continent, I am hopeful that relevant vaccines for the common strains within the meningitis belt region will be readily available for timely interventions due to the collaboration and teamwork of multicentre trials like ours,” Umesi said. “Together we can defeat meningitis,” Umesi said.