Taken together, in this work we provide proof of concept that intranodal tonsil vaccination with an MVA vaccine encoding SIVmac239-env and gag complements systemic vaccination to induce potent and balanced innate and adaptive immune responses that can protect not only from acquisition from a highly pathogenic SIVmac251 infection but also rapidly control acute viremia in cases of breakthrough infections. The gene discussed is ERVW-1; the disease is infection.