BackgroundElite controllers are able to control viral replication without antiretroviral therapy. Exceptional elite controllers do not show disease progression for more than 25 years. Different mechanisms have been proposed and several elements of both innate and adaptive immunity are implicated. Vaccines are immune stimulating agents that can promote HIV-RNA transcription; transient plasma HIV-RNA detectability has been described within 7–14 days after different vaccinations. The most reliable mechanism involved in virosuppressed people living with HIV is a generalized inflammatory response that activates bystander cells harboring latent HIV. So far no data about viral load increase in elite controllers after SARS-CoV-2 vaccination are reported in literature.Case presentationWe report the case of a 65-year-old woman of European ancestry, diagnosed with HIV-1/HCV co-infection more than 25 years ago. Since then, HIV-RNA remained undetectable and she never received ARV therapy. In 2021 she was vaccinated with mRNA-BNT162b2 vaccine (Pfizer-BioNTech®). She was administered with three doses in June, July and October 2021, respectively. The last available viral load was undetectable in March 2021. We observed an increase of VL at 32 cp/ml and 124 cp/mL, two and seven months after the second vaccine dose, respectively. During monthly follow-up, HIV-RNA gradually and spontaneously dropped becoming undetectable without ARV intervention. COVID-19 serology was positive with IgG 535 BAU/mL, showing response to vaccination. We measured total HIV-DNA at different time-points and we found it detectable both at the time of the higher plasma HIV-RNA (30 cp/10^6 PBMCs) and when it was undetectable (13 cp/10^6 PBMCs), in reduction.ConclusionsThis case is the first report, to our knowledge, describing a rebound of plasma HIV-RNA in an elite controller after three doses of mRNA-BNT162b2 vaccine for SARS-CoV-2. Concomitantly with a spontaneous reduction of plasma HIV-RNA ten months after the third dose of mRNA-BNT162b2 vaccine (Pfizer-BioNTech®) without antiretroviral therapy intervention, we observed a reduction of total HIV-DNA in peripheral mononuclear cells. The potential role of vaccinations in altering HIV reservoir, even in elite controllers when plasma HIV-RNA is undetectable, could be a valuable aspect to take into account for the future HIV eradication interventions.