Since the beginning of the epidemic, extensive research has been conducted in the field of HIV infection. Original research and subsequent meta-analyses have contributed to a better understanding of the disease. Epidemiologic research has shown, for example, that male circumcision reduces the risk of female-to-male transmission. Nevertheless, the question whether circumcision confers protection against HIV transmission in MSM remains open. Studies have shown a positive correlation between HIV and HSV-2 infection. However, a recent RCT found that suppressive antiherpes therapy did not affect rates of HIV acquisition. Meta-analytical studies have advanced the knowledge on the global prevalence of infection among MSM, and disparities among black and white MSM. They have also solidified the evidence that the prophylactic use of ARVs reduces the risk of MTCT. It has also been shown that prolonged ruptured of membranes increases the rates of vertical transmission, and that breastfeeding is associated with postnatal transmission. In addition, prognostic markers of disease progression have been identified. The introduction of ART has resulted in substantial improvements in morbidity and mortality for HIV-seropositive individuals. Several studies have defined recommended and alternative regimens. In a recent meta-analysis it was shown that in treatment naïve patients, NNRTI-based or boosted-PI-based regimens are superior to triple NRTI or unboosted PI-based regimens in terms of virologic suppression. Recent evidence has demonstrated that ART can be successfully used in Africa with better outcomes in those receiving free treatment. Regarding resistance testing in treatment-experienced patients with virologic failure, GRT offers a benefit of small magnitude and there is insufficient evidence to support the use of PRT, in contrast to current guidelines. Meta-analyses have also shown that interventions to improve adherence can be successfully implemented. Finally, the efficacy of the influenza and hepatitis vaccine in the setting of HIV infection has been analyzed. As our knowledge advances, further questions will inevitably arise and will need to be addressed in well-conducted trials.