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1.
Adv Sci (Weinh) ; : e2201294, 2022 Jul 27.
Article in English | MEDLINE | ID: covidwho-1958672

ABSTRACT

Soluble ACE2 (sACE2) decoys are promising agents to inhibit SARS-CoV-2, as their efficiency is unlikely to be affected by escape mutations. However, their success is limited by their relatively poor potency. To address this challenge, multimeric sACE2 consisting of SunTag or MoonTag systems is developed. These systems are extremely effective in neutralizing SARS-CoV-2 in pseudoviral systems and in clinical isolates, perform better than the dimeric or trimeric sACE2, and exhibit greater than 100-fold neutralization efficiency, compared to monomeric sACE2. SunTag or MoonTag fused to a more potent sACE2 (v1) achieves a sub-nanomolar IC50 , comparable with clinical monoclonal antibodies. Pseudoviruses bearing mutations for variants of concern, including delta and omicron, are also neutralized efficiently with multimeric sACE2. Finally, therapeutic treatment of sACE2(v1)-MoonTag provides protection against SARS-CoV-2 infection in an in vivo mouse model. Therefore, highly potent multimeric sACE2 may offer a promising treatment approach against SARS-CoV-2 infections.

2.
Vox Sang ; 117(7): 971-975, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1949883

ABSTRACT

BACKGROUND AND OBJECTIVE: The SARS-CoV-2 Omicron variant displays increased infectiveness as well as mutations resulting in reduced neutralizing activity of antibodies acquired after vaccination or infection involving earlier strains. To assess the ability of vaccinated COVID-19 convalescent plasma (CCP-V) collected before November 2021 to seroneutralize Omicron, we compared neutralizing antibody (nAb) titres of 63 samples against Omicron and earlier B.1 (D614G) strains. METHODS AND FINDINGS: Relationship between anti-Omicron titres and IgG anti-S1 levels (binding arbitrary unit: BAU/ml) was studied. Although correlated, anti-Omicron titres were significantly lower than anti-B.1 titres (median = 80 [10-1280] vs. 1280 [160-10,240], p < 0.0001). Omicron nAb titres and IgG anti-S1 levels were correlated (Spearman's rank correlation coefficient = 0.67). Anti-S1 IgG threshold at 7000 BAU/ml may allow to discard CCP-V without anti-Omicron activity (nAb titre <40). Conversely, only those with highest titres (≥160) had systematically anti-S1 IgG levels >7000 BAU/ml. CONCLUSION: A fraction of CCP-V collected before November 2021 retains anti-Omicron seroneutralizing activity that may be selected by quantitative anti-IgG assays, but such assays do not easily allow the identification of 'high-titre' CCP-V. However, collecting plasma from vaccinated donors recently infected with Omicron may be the best option to provide optimal CCP-V for immunocompromised patients infected with this variant.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/therapy , Humans , Immunization, Passive
3.
J Geriatr Oncol ; 13(6): 850-855, 2022 Jul.
Article in English | MEDLINE | ID: covidwho-1851497

ABSTRACT

PURPOSE: The COVID-19 vaccination campaign began in December 2020, in France, and primarily targeted the oldest people. Our study aimed to determine the level of acceptance of vaccination in a population of older patients with cancer. METHODS: From January 2021, we offered vaccination with the BNT162b2 COVID-19 vaccine to all patients 70 years and older referred to our geriatric oncology center in Marseille University Hospital (AP-HM) for geriatric assessment before initiation of an oncological treatment. Objectives were to evaluate acceptance rate of COVID-19 vaccination and to assess vaccine safety, reactogenicity, and efficacy two months after the first dose. RESULTS: Between January 18, 2021 and May 7, 2021, 150 older patients with cancer were offered vaccination after a geriatric assessment. The majority were men (61.3%), with a mean age of 81 years. The two most frequent primary tumors were digestive (29.4%) and thoracic (18%). The vaccine acceptance rate was 82.6% and the complete vaccination rate (2 doses) reached 75.3%. Among the vaccinated patients, 15.9% reported mild side effects after the first dose and 23.4% after the second dose, mostly arm pain and fatigue. COVID-19 cases were observed in 5.1% of vaccinated patients compared with 16.7% in unvaccinated patients. Of the 22 vaccinated patients who agreed to have their serum tested, 15 had antibodies against the spike protein at day 21 after the first dose. CONCLUSION: Our study showed a high acceptance rate of COVID-19 vaccination, with good tolerance in this frail population. These results highlight the benefits of organizing vaccination campaigns at the very beginning of oncological management in older patients. CLINICAL TRIAL REGISTRATION: This study was registered May 23, 2019 in ClinicalTrials.gov (NCT03960593).


Subject(s)
COVID-19 , Neoplasms , Vaccines , Aged , Aged, 80 and over , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Female , Humans , Male , Neoplasms/therapy , Vaccination
4.
Int J Environ Res Public Health ; 19(4)2022 02 10.
Article in English | MEDLINE | ID: covidwho-1690259

ABSTRACT

This study aimed to estimate the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection within the staff and student populations of the University of Corsica (France) during the second wave of the epidemic. METHODS: A cross-sectional survey was conducted from 23 November 2020 to 31 January 2021. The participants underwent blood sampling using a fingerstick procedure and completed an anonymized questionnaire. Sera were tested for the presence of anti-SARS-CoV-2 IgG (ELISA-S) and, if positive, with an in-house virus neutralization test (VNT). RESULTS: A total of 418 persons were included in the study. The overall seroprevalence was 12.8% (95% confidence interval (CI), 9.8-16.6%). A total of 15 (31%) of the 49 individuals who had a positive ELISA-S also had a positive VNT. Seropositivity was associated with living at the city campus during the week and on weekends (OR = 3.74 [1.40-12.00]), using public transportation/carpooling (OR = 2.00 [1.01-4.02]), and being in contact with a person who tested positive for SARS-CoV-2 (OR = 2.32 [1.20-4.40]). The main symptoms associated with seropositivity were "having had an acute respiratory infection" (OR = 3.05 [1.43-6.43]) and "experiencing loss of smell" (OR = 16.4 [5.87-50.7]). CONCLUSION: These results could be useful for SARS-CoV-2 prevention and control on university campuses.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19/epidemiology , Cross-Sectional Studies , Humans , Seroepidemiologic Studies
5.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-313774

ABSTRACT

We report infectivity of adult and pediatric COVID-19 patients in presence of viral shedding and anti-SARS-CoV-2 antibody response A total of 408 consequent samples from eleven adult and five pediatric patients with SARS-CoV-2 infection were included. The samples every second day from saliva, nasopharynx, feces, serum, urine, tear were studied by RT-PCR and viral culture. Anti-SARS-CoV-2 antibodies were measured. The median duration of RNA shedding in all specimens was 7(2-15) days in adults and 5(3-19) days in children. The median duration from onset of symptoms to admission was three days.The viral RNA was positive in 44.7 % of the nasopharynx and 37.6% of saliva samples up 16 days in adults and 19 days in chldren. The latest viral culture positivity was detected on day 8 of symptoms in nasopharynx. The viral RNA was found in 6.1% of feces, 4.4% ofserum, 4.3 % of tear, 2.9% of urine. The earliest seroconversion was the 7 th day for adults and 8 th day for children. Atthe 14 th day, total antibody positivity was 78% in adults, and 80% in children. After seroconversion, the viral RNA was still detected in the nasopharynx and saliva of three patients, however, the infectious virus was not present. Earlier hospital admission could be associated with shorter SARS-CoV-2 RNA shedding. The infectivity of patient is very low after 8 days of symptoms. The risk of fecal-oral transmission is very low, and strict hand hygiene measures could be preventive. The positive antibody test result could be used as a discharge criterion.

6.
Viruses ; 14(2)2022 01 25.
Article in English | MEDLINE | ID: covidwho-1649410

ABSTRACT

Healthcare workers (HCWs) are at increased risk of SARS-CoV-2 infection. The aim of the study was to estimate the SARS-CoV-2 seroprevalence among HCWs in Cochabamba, Bolivia and to determine the potential risk factors. In January 2021, a cross-sectional SARS-CoV-2 seroprevalence study was conducted in 783 volunteer clinical and non-clinical HCWs in tertiary care facilities. It was based on IgG detection using ELISA, chemiluminiscence, and seroneutralisation tests from dried blood spots. Analysis revealed a high seroprevalence (43.4%) of SARS-CoV-2 IgG antibodies. The combination of anosmia and ageusia (OR: 68.11; 95%-CI 24.83-186.80) was predictive of seropositivity. Belonging to the cleaning staff (OR: 1.94; 95%-CI 1.09-3.45), having more than two children in the same house (OR: 1.74; 95%-CI 1.12-2.71), and having been in contact with a close relative with COVID-19 (OR: 3.53; 95%-CI 2.24-5.58) were identified as risk factors for seropositivity in a multivariate analysis. A total of 47.5% of participants had received medication for COVID-19 treatment or prevention, and only ~50% of symptomatic subjects accessed PCR or antigenic testing. This study confirms a massive SARS-CoV-2 attack rate among HCWs in Cochabamba by the end of January 2021. The main risk factors identified are having a low-skilled job, living with children, and having been in contact with an infected relative in the household.


Subject(s)
Antibodies, Viral/blood , COVID-19/epidemiology , COVID-19/immunology , Health Personnel/statistics & numerical data , Adolescent , Adult , Antibodies, Viral/immunology , Bolivia/epidemiology , Cross-Sectional Studies , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Middle Aged , Prevalence , Risk Factors , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Seroepidemiologic Studies , Tertiary Healthcare/statistics & numerical data , Young Adult
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