Long-term antibody response following SPUTNIK V primary vaccination in healthcare workers with and without history of SARS-CoV-2 infection: Prospective cohort study from a hospital in Argentina

•After completing a two-dose Sputnik V schedule, all vaccinees developed antibodies.•Prior infection was associated with higher antibody concentrations.•Antibodies decreased significantly after 6 months in naïve subjects.•In subjects without infection, 17% were negative at day 180.•SARS-CoV2 infection after vaccination increased antibody concentrations.