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1.
Preprint in English | medRxiv | ID: ppmedrxiv-21267395

ABSTRACT

ObjectivesTo assess the humoral and cellular responses against SARS-CoV-2 Delta variant after BNT162b2 vaccination in PLWHIV. DesignMulticenter cohort study of PLWHIV, with a CD4 cell count <500/mm3 and a viral load <50 copies/ml on stable antiretroviral therapy for at least 3 months. MethodsAnti-SARS-CoV-2 Receptor Binding Domain IgG antibodies (anti-RBD IgG) were quantified and their neutralization capacity was evaluated using an ELISA (GenScript) and a virus neutralization test (VNT), against historical strain, Beta and Delta variants before vaccination (day 0) and one month after a complete vaccination schedule (M1). Results97 patients were enrolled in the study: 85 received 2 vaccine doses (11 previous COVID-19 and 1 premature exit). The seroconversion rate in anti-RBD IgG was 97% CI95[90%; 100%] at M1. Median (IQR) anti-RBD IgG titer was 0.97 (0.97-5.3) BAU/ml at D0 and 1219 (602-1929) at M1. Neutralizing antibodies (NAbs) capacity improved between D0 (15% CI95[8%; 23%]) and M1 (94% CI95[87%; 98%]) with the GenScript assay (p<0.0001). At M1, NAbs against historical strain, Beta and Delta variants were present in 82%, 77% and 84% patients respectively. The seroconversion rate and median anti-RBD IgG were 91% and 852 BAU/ml in patients with CD4<250/mm3 (n=13) and 98% and 1270 BAU/ml in patients with CD4>250/mm3 (n=64) (p=0.3994). 73% of patients with CD4<250 had NAbs and 97% of those with CD4>250 (p=0.0130). The NAbs against Beta variant was elicited in 50% in CD4<250 and in 81% in CD4>250 (p=0.0292). No change in CD4+ or CD8+ T cells count was observed while a decrease of CD19+ B cells count was observed (208 {+/-}124 cells/mm3 at D0 vs 188 {+/-}112 cells/mm3 at M1, p<0.01). No notable adverse effects or COVID-19 were reported. ConclusionsThese results show a high seroconversion rate with a Delta neutralization in PLWHIV patients after a complete BNT162b2 vaccination schedule.

2.
Preprint in English | medRxiv | ID: ppmedrxiv-20152660

ABSTRACT

BackgroundCOVID-19 (COronaVIrus Disease 2019) is an infectious respiratory disease caused by the novel SARS-CoV-2 virus. Rapid Diagnostic Tests (RDTs) have been developed to detect specific antibodies, IgG and IgM, to SARS-CoV-2 virus in human whole blood and easily usable by the general population are needed in order to alleviate the lockdown that many countries have initiated in response to the growing COVID-19 pandemic. A real-life study has been conducted in order to evaluate the performance of the COVID-PRESTO(R) RDT and the results have been submitted for publication and are currently under review. Even if this test showed very high sensitivity and specificity in a laboratory setting when used by trained professionals, it needs to be further evaluated for practicability when used by common folk in order to be approved by health authorities for in-home use Methods142 participants were recruited between March 2020 and April 2020 among non-medical populations in central France (nuclear plants workers, individuals attending the Orleans University Hospital vaccination clinic and Orleans University Hospital non-medical staff). Instructions for use with or without a tutorial video was made available to the volunteers. Two separate objectives were pursued: evaluation of the capability of participants to obtain an interpretable result, and evaluation of the users ability to read the results. Results88.4 % of the test users judged the instruction for use leaflet to be clear and understandable. 99.3 % of the users obtained a valid results and according to the supervisors 92.7% of the tests were properly performed by the user. Overall, 95% of the users gave positive feedback toward the COVID PRESTO(R) as a potential self-test. No influence of age and education was observed. ConclusionCOVID-PRESTO(R) was successfully used by an overwhelming majority of participants and its utilization was judged very satisfactory, therefore showing a promising potential as a self-test to be used by the general population. This RDT can become an easy-to-use tool to help know whether individuals are protected or not, particularly in the perspective of a second wave or a mass vaccination program.

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