Abstract: In one embodiment, there is provided a method for treatment or prophylaxis of one or more symptoms of a retrovirus infection such as HIV infection, comprising the administration of poxvirus vector encoding a retrovirus antigen and a cytokine, or a functional homolog, derivative part or analog thereof, in conjunction with anti-retroviral drug therapy wherein said polypeptide and/or cytokine are expressed in a subject and are effective in maintaining a low viral load in a subject for a period of time, for example effectively preventing, reducing or delaying viral rebound during interruption of anti-retroviral drug treatment.