The COVID-19 resource centre is hosted on Elsevier Connect, the company’s public news and information website. response after a first dose of COVID-19 vaccine suggesting that a solitary dose of vaccine should be proposed to seropositive individuals. As of June, 21, 2021, more than 31 million individuals received at least one dose of vaccine against COVID-19 in France which global human population is about 67 million [https://solidarites-sante.gouv.fr/grands-dossiers/vaccin-covid-19/article/le-tableau-de-bord-de-la-vaccination]. The Haute Autorit de Sant (Offers) recommends that one dose only of anti-SARS-CoV-2 vaccine become proposed to individuals previously infected with the virus. Because infected individuals may have been asymptomatic and not tested, screening through quick serologic test is recommended in folks who are unsure about their status. This may avoid injecting unneeded second doses of vaccine in already infected individuals and saving doses for those in need [2]. Inside a serological monitoring study carried out in the Provence-Alpes-C?te dAzur region, Amyloid b-peptide (1-42) (rat) from May, 11 to May 17, 2020, 3.3% of 397 individuals tested positive [3]. In our vaccination center we implemented a pre-vaccination serological testing strategy starting on May 10, 2021 and provide here an interim analysis of results until June 15, 2021. All individuals consulting for a first dose of vaccine against COVID-19 were proposed a rapid whole-blood finger-stick immune-chromatographic serologic test (Biosynex COVID-19 BSS, SW40005, Biosynex, Switzerland). The BioSynex test was selected because of its good level of sensitivity and specificity reported previously [4], [5]. Data offered herein were collected retrospectively from your routine care establishing using the electronic health recording system of the hospital. 541 individuals were included of whom 309 (57.1%) were woman, having a mean age of 40?years (ranging 18C97?years). The vast majority, (522 (96.5%)) Keratin 16 antibody had a negative Amyloid b-peptide (1-42) (rat) result and were eligible for two doses of vaccine. 19 were positive (3.5%). Among 19 individuals having a positive result, ten (52.6%) were woman and their mean age was 45?years (ranging 20C69?years), which did not significantly differed from negative individuals. Most positive individuals experienced positive IgG only, three experienced both positive IgG and IgM and one experienced positive IgM only (Table 1). Among these 19 individuals, ten experienced a PCR recorded past SARS-CoV-2 illness and received one dose of vaccine only. Systematic screening allowed identifying nine additional individuals with a positive anti-SARS-CoV-2 serology who were not aware of a COVID-19 illness and who received one dose of vaccine only. Of notice, two of these nine patients experienced symptoms compatible with COVID-19 and one was in close contact with her spouse that experienced a confirmed SARS-CoV-2 infection. Systematic serological screening allowed therefore saving 9/541 (1.7%) doses of vaccine. To conclude, the benefit of systematically screening individuals before a first dose of COVID-19 vaccine appears to be limited, in our encounter, allowing saving less than 2% vaccine doses. Assessment with related studies carried out in area with a higher incidence of COVID-19 will Amyloid b-peptide (1-42) (rat) become of interest. Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal human relationships that could have appeared to influence the work reported with this paper. Acknowledgement We say thanks to Cdrick Hamidou for his superb technical work. Honest approval This study was authorized by the Ethics Committee of our institute (Ref. 2021-022). Consent to participate Participant were proposed serological testing as part of routine care. No written educated consent was required. Consent to publish Not applicable. Authors contribution FF, DR and.