Menactra Vaccine Immunogenicity. Five serogroups, A, B, C, Y and W-135 are responsible for almost all cases of invasive meningococcal disease worldwide.3. Menactra is the first meningococcal conjugate vaccine in the United States that helps protect against 4 vaccine-preventable serogroups (A, C, Y, and W-135).1,2,4.