Meningococcal vaccines for the United Kingdom

Area of Science:

• * Vaccinology and Immunology
• * Microbial Pathogenesis
• * Public Health

Background:

• * Urgent need for new meningococcal vaccines in the UK, primarily targeting serogroups B and C.
• * Infants are most affected by Neisseria meningitidis but respond poorly to vaccines.
• * Existing serogroup B vaccines face challenges due to poor infant immunogenicity of capsular polysaccharides.

Purpose of the Study:

• * To explore alternative antigens for infant meningococcal vaccines.
• * To evaluate the efficacy of outer membrane proteins (OMP) and conjugate polysaccharides.
• * To address the immunological challenges in vaccinating infants against meningococcal disease.

Main Methods:

• * Review of existing and developing meningococcal vaccine strategies.
• * Consideration of outer membrane proteins (OMP), iron regulating proteins, and lipopolysaccharide as alternative antigens.
• * Analysis of phase 2 and phase 3 trial data for OMP-based vaccines in various countries.
• * Evaluation of conjugate vaccines for serogroup C and AC polysaccharides.

Main Results:

• * OMP-based vaccines have undergone several phase 3 trials globally.
• * Phase 2 trials have compared different OMP vaccines.
• * Conjugate vaccines show immunogenicity in infants but may have waning antibody titres.
• * A phase 2 trial of a hexavalent class 1 OMP vaccine is ongoing in infants.

Conclusions:

• * Developing effective meningococcal vaccines for infants remains a significant challenge.
• * Alternative antigens like OMP show promise but require further investigation.
• * Conjugate vaccines offer improved infant immunogenicity for serogroup C but antibody persistence is a concern.