The activities of the HIV viral and biology unit (UBVVIH) include research, service to the National Health System (NHS) and the administration of Justice and teaching. Its main lines of research are molecular epidemiology and HIV-1 phylogeny, in which the UBVVIH has carried out numerous national and international collaborations, focusing on the identification of viral genetic forms and the study of their correlations with epidemiological variables. Related lines are phylodynamics and phylogeography, which study the origin and dynamics of growth and spread of HIV-1 variants. Such studies can be used to better understand the evolution of the epidemic and to plan public health actions. 

The UBVHIV also produces and characterises primary isolates and functional clones of the envelope of various genetic forms of HIV-1, which are deposited in repositories and used by numerous international groups. Other lines of research are described in the corresponding section. In terms of service to the NHS, the UBVVIH carries out antiretroviral resistance tests and prediction of tropism as a therapeutic guide in HIV-1 infected patients. As for its collaboration with the Justice Administration, the UBVVIH carries out expert opinions through phylogenetic studies of sequences for legal cases of possible HIV transmissions.