Immunogenic compositions and prophylactic or therapeutic vaccines for use in protecting and treating against human cytomegalovirus (CMV) are disclosed. Subunit vaccines comprising a human CMV protein complex comprising pUL128 or pUL130, and nucleic acid vaccines comprising at least one nucleic acid encoding a CMV protein complex comprising pUL128 or pUL130 are described. Also disclosed are therapeutic antibodies reactive against a CMV protein complex comprising pUL128 or pUL130, as well as methods for screening compounds that inhibit CMV infection of epithelial and endothelial cells, methods for immunizing a subject against CMV infection, methods for determining the capability of neutralizing antibodies to inhibit CMV infection of cell types other than fibroblasts, and methods of diminishing an CMV infection.