Capillary whole-blood IgG-IgM COVID-19 self-test as a serological screening tool for SARS-CoV-2 infection adapted to the general public

The practicability of a prototype capillary whole-blood IgG-IgM COVID-19 self-test (Exacto® COVID-19 self-test, Biosynex Swiss SA, Freiburg, Switzerland) as a serological screening tool for SARS-CoV-2 infection adapted to the general public was evaluated in a cross-sectional, general adult population study performed between April and May 2020 in Strasbourg, France, consisting of face-to-face, paper-based, semi-structured, and self-administrated questionnaires. Practicability was defined as the correct use of the self-test and the correct interpretation of the result. The correct use of self-test was conditioned by the presence of the control band after 15-min of migration. The correct interpretation of the tests was defined by the percent agreement between the tests results read and interpret by the participants compared to the expected results coded by the numbers and verified by trained observers. A total of 167 participants (52.7% female; median age, 35.8 years; 82% with post-graduate level) were enrolled, including 83 and 84 for usability and test results interpretation substudies, respectively. All participants (100%; 95% CI: 95.6–100) correctly used the self-test. However, 12 (14.5%; 95% CI: 8.5–23.6) asked for verbal help. The percent agreement between the tests results read and interpret by the participants compared to the expected results was 98.5% (95% CI: 96.5–99.4). However, misinterpretation occurred in only 2.3% of positive and 1.2% of invalid test results. Finally, all (100%) participants found that performing the COVID-19 self-test was easy; and 98.8% found the interpretation of the self-test results easy. Taken together, these pilot observations demonstrated for the first-time, high practicability and satisfaction of COVID-19 self-testing for serological IgG and IgM immune status, indicating its potential for use by the general public to complete the arsenal of available SARS-CoV-2 serological assays in the urgent context of the COVID-19 epidemic.

Yes -all data are fully available without restriction whether a person has already been infected by SARS-CoV-2. Serologic tests will be needed to 80 assess the response to vaccine candidates and to map levels of immunity in communities. These    consisting of face-to-face, paper-based, semi-structured, and self-administrated questionnaires.

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Strasbourg is the capital city of the Grand Est province, which was one of the regions affected 141 the most by the SARS-CoV-2 epidemic in France [25].

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All participants accepted voluntarily to be included. Eligible participants had an age ≥ 143 18 years, wanted to know their SRAS-CoV-2 serology status, were capable to speak and read 144 in French, and gave their consent to participate in the study. All trained individuals (physicians, 145 nurses, and biologist) in rapid diagnostic tests were excluded. Informed written consent was 146 signed by all participants. Ethical approval for this study was obtained from the local scientific 147 committee of Parc de l'Innovation, Strasbourg, France.    performing the self-test and the interpretation of test results. In order to achieve this, a sealed 182 randomization envelope was used sequentially. In each group, before starting the survey, a pre-183 test satisfaction questionnaire was completed by the participants.  to the participants for interpretation after successive random selection of four tests (Fig 3).

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These standardized tests were coded by numbers to determine the expected results.  The observer noted the number of the drawn test and the result given by the participant.     substudies 1 and 4), and among 229 10 them, 83 were assigned after randomization in substudy 2 and 84 in substudy 3 (Fig 2). The 230 demographic characteristics and medical history of study participants are shown in Table 1.

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Overall, 88 (52.7%) were female. The mean age was 38.6 (SD: 13.8) years, and around one half   We herein report on our recent experience during the last COVID-19 epidemic peak 334 period of the practicability of a prototype capillary whole-blood COVID-19 self-test for IgG 335 and IgM against SARS-CoV-2 serological screening among adult volunteers living in France.

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Our assessment of usability was made with reference to our previous experience in evaluating 337 HIV self-testing according to the WHO recommendations [26]. Overall, the vast majority of  to practice [29]. The expected results of substudy 1 are, therefore, important for the following 352 practicability substudies 2 and 3, because it is mandatory to check that the instructions for use Some difficulty in the correct use of the pipette to transfer the blood sample was the principal 371 reported concern encountered and was the most common reason for oral help. In previous 372 reports on HIV self-testing, the difficulties in self-lancing and blood transfer to the cassette  IgG, alone or associated with IgM). Thus, COVID-19 self-testing for serological screening 443 could be proposed to identify exposed patients that are presumptively immune to SARS-CoV- population of "recovered" individuals would allow many to return to work, lead to partial lifting 465 of "stay-at-home" or "shelter-in-place" orders, and would help get the economy back to normal,