SARS-CoV-2 IgG seroprevalence surveys in blood donors before the vaccination campaign, France 2020-2021
Pierre Gallian,
Nathanaël Hozé,
Nadège Brisbarre,
Paola Mariela Saba Villarroel,
Elif Nurtop,
Christine Isnard,
Boris Pastorino,
Pascale Richard,
Pascal Morel,
Simon Cauchemez,
Xavier de Lamballerie
Affiliations
Pierre Gallian
Établissement Français du Sang, La Plaine Saint Denis 93218, France; Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France; Corresponding author
Nathanaël Hozé
Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, Université Paris Cité, UMR2000, CNRS, 75015 Paris, France
Nadège Brisbarre
Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France; Établissement Français du Sang Provence Alpes Côte d'Azur et Corse, 13005 Marseille France
Paola Mariela Saba Villarroel
Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France
Elif Nurtop
Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France
Christine Isnard
Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France; Établissement Français du Sang Provence Alpes Côte d'Azur et Corse, 13005 Marseille France
Boris Pastorino
Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France
Pascale Richard
Établissement Français du Sang, La Plaine Saint Denis 93218, France
Pascal Morel
Établissement Français du Sang, La Plaine Saint Denis 93218, France; UMR RIGHT 1098, Inserm, Établissement Français du Sang, University of Franche-Comté, 25000 Besançon, France
Simon Cauchemez
Mathematical Modelling of Infectious Diseases Unit, Institut Pasteur, Université Paris Cité, UMR2000, CNRS, 75015 Paris, France
Xavier de Lamballerie
Unité des Virus Émergents (UVE: Aix-Marseille University - IRD 190 - Inserm 1207), 13005 Marseille, France
Summary: We conducted a cross-sectional study for SARS-CoV-2 anti-S1 IgG prevalence in French blood donors (n = 32605), from March-2020 to January-2021. A mathematical model combined seroprevalence with a daily number of hospital admissions to estimate the probability of hospitalization upon infection and determine the number of infections while correcting for antibody decay. There was an overall seroprevalence increase over the study period and we estimate that ∼15% of the French population had been infected by SARS-CoV-2 by January-2021. The infection/hospitalization ratio increased with age, from 0.31% (18-30yo) to 4.5% (61-70yo). Half of the IgG-S1 positive individuals had no detectable antibodies 4 to 5 months after infection. The seroprevalence in group O donors (7.43%) was lower (p = 0.003) than in A, B, and AB donors (8.90%). We conclude, based on seroprevalence data and mathematical modeling, that a large proportion of the French population was unprotected against severe disease prior to the vaccination campaign.
