Pentavalent meningitis vaccine continues to show promise in phase 3 trial
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Key takeaways:
- A pentavalent vaccine against meningitis continued to show promise in a phase 3 trial in Africa’s meningitis belt.
- Researchers found no safety concerns for the vaccine.
A pentavalent vaccine against Neisseria meningitidis was shown to be safe and effective in a phase 3 trial conducted among children and young adults in Africa’s meningitis belt, researchers reported in The New England Journal of Medicine.
Previously, a phase 2 trial demonstrated that a single dose of the vaccine, NmCV-5, elicited immune responses similar the response from two doses of MenACWY-D, one of the three commercially available quadrivalent meningococcal conjugate vaccines.
In the new trial, the investigational vaccine elicited immune responses to the four serotypes included in the MenACWY-D vaccine, in addition to serogroup X, which has increasingly been reported recently in Africa’s meningitis belt.
“The highest incidences of meningitis and death from the disease occur across the African meningitis belt, which stretches from Gambia and Senegal in the west to Ethiopia in the east, where meningitis epidemics, predominantly caused by Neisseria meningitidis, occur on a background of high rates of endemic disease,” Fadima C. Haidara, MD, of the Center for Vaccine Development in Mali, and colleagues wrote.
According to the researchers, although six serogroups of meningococcus — A, B, C, W, X, and Y — can cause invasive disease, serogroup A has been “virtually eliminated” following mass vaccination campaigns across the meningitis belt.
Although WHO has licensed and prequalified four quadrivalent meningococcal ACWY vaccines, their use in the meningitis belt “has been limited by supply and cost constraints,” they wrote.
Haidara and colleagues examined the effectiveness of NmCV-5 among 1,800 participants aged 2 to 29 years in Mali and Gambia who either received the experimental vaccine or MenACWY-D as a control group. In the vaccine group, the proportion of participants who experienced a response to a serotype ranged from 70.5% (95% CI, 67.8%-73.2%) for serogroup A to 98.5% (95% CI, 97.6%99.2%) for serogroup W. Additionally, 97.2% (95% CI, 96%98.1%) had a response to X.
Regarding safety, the incidence of systemic adverse events were similar in both groups — 11.1% in the NmCV-5 group and 9.2% in the MenACWY-D group, with all events being “mild or moderate in severity and resolved with no more than simple analgesia,” causing “no evident safety concerns,” the authors wrote.
“On the basis of these trial data, NmCV-5 may emerge as a tool to support meningococcal disease control, particularly across the meningitis belt of sub-Saharan Africa, and thus may contribute to epidemic elimination and the other goals of the global road map for the Defeating Meningitis by 2030 program,” they wrote.
In an accompanying editorial David S. Stephens, MD, chair of the department of medicine at Emory University and vice president for research of that school’s Woodruff Health Sciences Center, noted that there is another trial underway to test the vaccine in infants.
“Although challenges remain, we are a step closer to worldwide control of meningococcal disease and the burden of meningitis with these efforts,” Stephens said.
References:
Haidara FC, et al. N Engl J Med. 2023;doi:10.1056/NEJMoa2214924.
Stephens DS, et al. N Engl J Med. 2023;doi:10.1056/NEJMoa2301698.
Tapia MD, et al. N Engl J Med. 2021;doi:10.1056/NEJMoa2013615.