Past SARS-CoV-2 infection elicits a strong immune response after a single vaccine dose

Chahla, R. E.; Tomas-Grau, R. H.; Cazorla, S. I.; Ploper, D.; Vera Pingitore, E.; Aguilar Lopez, M.; Aznar, P.; Alcorta, M. E.; Velez, E. M. d. M.; Stagnetto, A.; Avila, C. L.; Maldonado Galdeano, C.; Socias, S. B.; Heinze, D.; Navarro, S. A.; Llapur, C.; Costas, D.; Flores, I.; Apfelbaum, G.; Mostoslavsky, R.; Mostoslavsky, G.; Perdigon, G. d. V.; Chehin, R.

We hypothesized that in individuals with previous SARS-CoV-2 infection, the first vaccine dose would work as a booster, eliciting a faster and more intense immune response. We herein describe antibody responses to the first and second doses of Gam-COVID-Vac (SPUTNIK V) vaccine in health personnel of Tucuman, Argentina, with previous COVID-19 and compared it with uninfected personnel. Individuals with anti-SARS-CoV-2 titers at baseline showed significantly higher responses to the first dose than people with no prior history of disease (p <0.0001), with titers higher to those registered after the second dose in the control group, representing a clear secondary antibody response. This suggests that a single dose of SPUTNIK V for people with previous SARS-CoV-2 infection could contribute to a better use of available doses.