Developing vaccines to prevent ETEC bacteria adherence and colonization, however, is hampered by the heterogeneity of ETEC bacterial adhesins. Different ETEC strains produce immunologically heterogeneous adhesins [8–10]. Antibodies derived from one type of adhesin may not block attachment of ETEC bacteria expressing different adhesins. The conventional approach by mixing together several live or killed strains that express a few different adhesins led to vaccine candidates that induce antibodies against homologous adhesins [11–14]. Recently, a novel strategy using reverse vaccinology and computer-aided structure-based multiepitope fusion antigen (MEFA) vaccine design has been explored to develop a safer and more effective ETEC vaccine.