Serum Institute's ACWYX vaccine candidate demonstrates strong safety and immunogenicity

May 25, 2023 by PATH

Results from a Phase 3 clinical study of a pentavalent meningococcal meningitis vaccine candidate designed for use in the African meningitis belt demonstrate it to be safe, well tolerated, and capable of producing strong immune responses to all five serogroups.

Detailed results from a Phase 3 study of Serum Institute of India Pvt. Ltd.'s (SIIPL's) NmCV-5 vaccine candidate, a conjugate vaccine designed to protect against meningococcal serogroups A, C, W, Y, and X, were published in the New England Journal of Medicine.

Meningococcal meningitis, a type of bacterial meningitis, is one of the most feared diseases in Africa. It is responsible for deadly annual outbreaks and epidemics that have led to tens of thousands of cases and thousands of deaths each year.

Existing polyvalent meningococcal conjugate vaccines are often cost prohibitive for people living in countries with low- and middle-income economies. NmCV-5 is designed to be affordable for low-resource countries, which suffer the greatest disease burden and are where people are most likely to experience severe outcomes. Moreover, it is the first vaccine to protect against meningococcal serogroup X, which in recent years has increased in prevalence in the meningitis belt.

With funding from the UK’s Foreign, Commonwealth and Development Office, SIIPL, with PATH as a collaborating partner, sponsored the Phase 3 study that took place between August 2019 and June 2021 in Bamako, Mali and Banjul, The Gambia. A total of 1,800 people between the ages of 2 and 29 participated in the study and received either a single dose of NmCV-5 or a licensed quadrivalent meningococcal comparator vaccine. Analysis showed that NmCV-5 elicited immune responses comparable to and sometimes higher than Menactra®, the comparator vaccine.

These promising results demonstrate NmCV-5's potential to one day eliminate meningococcal meningitis epidemics from Africa and support a pathway toward licensure and global use. NmCV-5 is currently licensed for use in people between 18 and 85 years of age in India and is undergoing regulatory review for global use.

About meningococcal meningitis

Meningococcal meningitis can occur anywhere but is most prevalent in Africa’s meningitis belt, a string of 26 countries stretching from Senegal and The Gambia in the west to Ethiopia in the east with an at-risk population of about 450 million. Every year, people living in these countries face the threat of meningitis epidemics during the dry season from January to June. The recurring epidemics place enormous burdens on local health systems and inflict damage that remains long after the disease passes. Even with timely antibiotic treatment, one in ten infected people will die within two days of the onset of symptoms; without treatment, up to 50 percent of those infected may die.

NmCV-5 builds on the legacy of MenAfriVac®—also developed by SIIPL, in collaboration with PATH and the World Health Organization (WHO)—a conjugate vaccine tailor-made for Africa that eliminated the circulation of meningococcal serogroup A wherever the vaccine has been used. NmCV-5, by targeting all five of the major serogroups causing meningococcal disease in the meningitis belt, extends SIIPL’s and PATH’s commitment to make vaccines available for the people who need them most, at a price they can afford.

The development of NmCV-5 aligns with WHO’s Defeating Meningitis by 2030 initiative, which aims to overcome bacterial meningitis as a public health threat and lays out a roadmap for how to do so. Reducing cases and deaths from vaccine-preventable bacterial meningitis is a critical component of that strategy, and uptake of multivalent meningococcal vaccines is identified as a landmark achievement. SIIPL and PATH’s work to develop NmCV-5 is essential for increasing tools in the global meningococcal meningitis prevention toolkit.