Safety and Immunogenicity of MVA.HIVconsv in HIV-1 Seropositive Adults on HAART

Inclusion Criteria: * Male or female, aged 18-60 years * Confirmed HIV-1 seropositive * Willing and able to give written informed consent for participation in the study * Treated continuously with a combination of 3 or more antiretroviral agents for the preceding 12 months * Willing and able to adhere to an effective ART regimen for the duration of the study (switching from current regimen is allowed if for reasons of tolerability or toxicity) * CD4 cell count \> 350 cells/μl at screening and at the preceding clinic visit * Plasma viral load \< 50 copies / ml at screening and at the preceding clinic visit * No new AIDS-defining diagnosis or progression of HIV-related disease in the preceding 6/12 months * Haematological and biochemical laboratory parameters as follows: * Haemoglobin \> 10g/dl * Platelets \> 100,000/μl * ALT ≤ 2.5 x ULN * Creatinine ≤ 1.3 x ULN * Serology: negative for hepatitis B surface antigen OR HbsAg positive with HBV DNA \< 1000 copies/ml; negative for hepatitis C antibodies OR confirmed clearance of HCV infection (spontaneous or following treatment); negative syphilis serology or documented adequate treatment of syphilis if positive EIA IgG or TPHA * Available for follow up for duration of study (screening + 38 weeks) and willing to comply with the protocol requirements * Women of child-bearing age must not be pregnant, planning a pregnancy or breast-feeding. Sexually active women must be willing to use an approved method of contraception from screening until 4 months after the third immunisation. Sexually active men in heterosexual relationships must be willing to use an approved method of contraception with their partners from screening until 4 months after the third immunisation. Exclusion Criteria: * Confirmed HIV-2 seropositive * Positive pregnancy test * Participation in another clinical trial within 12 weeks of study entry * History of autoimmune disease other than HIV-related auto-immune disease which has resolved with ART * History or clinical manifestations of any physical or psychiatric disorder which could impair the subject's ability to complete the study * History of anaphylaxis or severe adverse reaction to vaccines * History of alcohol or drug dependency which could, in the opinion of the investigators, impair the subject's ability to complete the study * Previous immunisation with a recombinant MVA vaccine * Immunisation with any experimental immunogens within 6 months of study entry * Receipt of blood products or immunoglobulins within 6 months of study entry * Treatment for cancer or lymphoproliferative disease within 1 year of study entry * Receipt of vaccines other than Hepatitis B vaccine within 2 weeks of study entry or planned receipt within 2 weeks of vaccination * Any other prior therapy which, in the opinion of the investigators, would make the individual unsuitable for the study or influence the results of the study * Current or recent use (within last 3 months) of interferon or systemic corticosteroids or other immunosuppressive agents