CD79A and infection: Since intestinal IgA antibody levels, which differ from the serum vibriocidal antibodies are believed to mediate the protection after vaccination, also decline within approximately one year while the immunological memory for an anamnestic response persists for many years [18] the most plausible explanation for long-lasting protection despite waning antibody titers is a rapid anamnestic response upon re-exposure curtailing the infection before it causes illness [19].