An isolated polypeptide comprising: a first antigenic polypeptide, wherein the first antigenic polypeptide: a. comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 29; b. is capable of initiating an immune response to the first oncogenic viral polypeptide in an immune-competent host; and c. is non-oncogenic in the immune-competent host; and a second antigenic polypeptide, wherein the second antigenic polypeptide: a. comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 30; b. is capable of initiating an immune response to the second oncogenic viral polypeptide in an immune-competent host; and c. is non-oncogenic in the immune-competent host; wherein the first antigenic polypeptide has the following mutations relative to SEQ ID NO:2: a. a point mutation at L50; b. a point mutation at E148; c. a point mutation at T149; d. a point mutation at Q150; and e. a point mutation at L151; and wherein the second antigenic polypeptide has the following mutations relative to SEQ ID NO: 4: a. a point mutation at H2; b. a point mutation at C24; c. a point mutation at E46; and d. a point mutation at L67. a first antigenic polypeptide, wherein the first antigenic polypeptide: a. comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 29; b. is capable of initiating an immune response to the first oncogenic viral polypeptide in an immune-competent host; and c. is non-oncogenic in the immune-competent host; and a. comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 29; b. is capable of initiating an immune response to the first oncogenic viral polypeptide in an immune-competent host; and c. is non-oncogenic in the immune-competent host; a second antigenic polypeptide, wherein the second antigenic polypeptide: a. comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 30; b. is capable of initiating an immune response to the second oncogenic viral polypeptide in an immune-competent host; and c. is non-oncogenic in the immune-competent host; a. comprises an amino acid sequence having at least 70% sequence identity to the amino acid sequence of SEQ ID NO: 30; b. is capable of initiating an immune response to the second oncogenic viral polypeptide in an immune-competent host; and c. is non-oncogenic in the immune-competent host; wherein the first antigenic polypeptide has the following mutations relative to SEQ ID NO:2: a. a point mutation at L50; b. a point mutation at E148; c. a point mutation at T149; d. a point mutation at Q150; and e. a point mutation at L151; a. a point mutation at L50; b. a point mutation at E148; c. a point mutation at T149; d. a point mutation at Q150; and e. a point mutation at L151; and wherein the second antigenic polypeptide has the following mutations relative to SEQ ID NO: 4: a. a point mutation at H2; b. a point mutation at C24; c. a point mutation at E46; and d. a point mutation at L67. a. a point mutation at H2; b. a point mutation at C24; c. a point mutation at E46; and d. a point mutation at L67.