Quick Answer
Meningococcal strains are different groups of Neisseria meningitidis bacteria that can cause meningitis and septicaemia. The letters, such as A, B, C, W and Y, identify different serogroups. Some vaccines protect against one strain, while MenACWY protects against four important travel-related strains.
Introduction
If you have heard about meningitis vaccines, you may have noticed…