In March 2023 GSK announced positive headline results from a Phase III trial evaluating its MenABCWY combination vaccine candidate. Assessing safety, tolerability, and immunogenicity, the trial started in August 2020. All primary endpoints were met, and the vaccine candidate was “well tolerated” and displayed a safety profile consistent with Bexsero and Menveo.  

MenABCWY in trial 

MenABCWY combines the antigenic components of GSK’s previously licensed meningococcal vaccines, Bexsero (MenB) and Menveo (MenACWY). Targeting all five Neisseria meningitides serogroups (A, B, C, W, and Y), MenABCWY met non-inferiority endpoints in terms of immune response.  

The candidate vaccine was administered as two doses given 6 months apart in healthy individuals between the ages of 10 and 25. The trial was randomised, controlled, observer-blind, and multi-country. It is part of a “comprehensive programme to generate clinical evidence on the benefits of meningococcal immunisation”. Around 3,650 participants were enrolled globally.  


GSK describes Invasive meningococcal disease (IMD) as an “uncommon but serious illness”. It can cause “life-threatening complications or even death” as a major cause of meningitis and septicaemia.  

“Among those contracting meningococcal diseases, one in ten will die, sometimes in as little as 24 hours, despite treatment. One-in-five survivors suffers long-term consequences, such as brain damage, amputations, hearing loss, and nervous system problems.” 

The previously mentioned serogroups A, B, C, W, and Y account for “nearly all IMD cases in most of the world”, yet no licensed combination vaccine offers protection in a single vaccine. GSK refers to two separate vaccines, requiring four injections, that are available in the US. However, “low awareness of the disease” has led to “sub-optimal immunisation coverage rates”.  

An encouraging step 

Dr Tony Wood, Chief Scientific Officer at GSK, described the “statistically significant Phase III data” as a “very encouraging step”. Dr Wood suggests that use of the candidate could “drive significant public health impact”.  

“In addition, our 5-in-1 meningococcal vaccine candidate builds on our global leadership in meningococcal vaccines and commitment to innovation.”  

GSK will continue to collaborate with regulators to review the full data set and intends to present a publication and further information at future scientific meetings. For more discussion on the importance of combination vaccines at the World Vaccine Congress in Washington next month, get your tickets here.