Anal Monkeypox Disease: Description of 65 Cases.

BACKGROUND: Monkeypox is a zoonosis endemic in Africa caused by 3 orthopoxvirus clades. Knowledge of the disease is limited, but a worldwide outbreak involving a new route of transmission was declared in April 2022. OBJECTIVE: This study aimed to describe anal symptoms and outcomes in patients infected with Monkeypox virus presenting to an emergency proctology unit in Paris. DESIGN: This was an observational study. SETTING: We reported anal symptoms of all consecutive patients with monkeypox anal infection in a single proctology center between June 16, 2022, and July 26, 2022. Association with sexually transmitted infections and outcomes were also recorded. PATIENTS: Sixty-five men with a mean age of 39.6 (19.9-64.6) years with confirmed monkeypox anal infection were included in the study. MAIN OUTCOME MEASURES: Anal symptoms and their severity were clinically assessed. A favorable outcome consisted of a complete resolution of clinical manifestation. RESULTS: Sexual transmission was reported in 51 patients (78.4%), among whom 63 (97%) were men who have sex with men. Twenty-eight (43%) were living with HIV, and 24 (36.9%) were taking tenofovir/emtricitabine for HIV preexposure prophylaxis. Anal symptoms appeared first in 36 patients (55.4%) and skin rash or other general symptoms in 22 patients (33.8%). Incubation time was 6.9 (1-26) days. Symptoms included painful perianal (n = 42 patients; 64.6%), anal (n = 28, 43%), and rectal (n = 25; 38.4%) ulcerations and perianal vesicles (n = 24; 36.9%). Proctitis was observed in 49 patients (75.4%). It was mild in 20 (40.8%) and intense in 29 (59.2%), and severe proctitis mimicking high intersphincteric suppuration was found in 4 (8.2%). Fifteen patients (23.1%) had concurrent sexually transmitted infection and 3 were hospitalized. Complete symptom resolution occurred within 12 days. LIMITATIONS: We performed a single-center study during a short period of time. CONCLUSIONS: Proctological symptoms are frequent in the current outbreak of monkeypox disease, probably linked to the route of transmission. Rectal ulcerations mimicking high intersphincteric suppuration should be recognized to avoid unnecessary surgery. See Video Abstract . ENFERMEDAD ANAL DE LA VIRUELA DEL MONO DESCRIPCIN DE CASOS: ANTECEDENTES:La viruela del simio mono es una zoonosis endémica en África causada por tres clados de orthopoxvirus. El conocimiento de la enfermedad es limitado, pero en abril de 2022 se declaró un brote mundial que implica una nueva vía de transmisión.OBJETIVO:Describir los síntomas anales y los resultados en pacientes que sufren de infección por Monkeypox que asistieron a una unidad de proctología de emergencia en París.DISEÑO:Un estudio observacional.ESCENARIO:Informamos los síntomas anales de todos los pacientes consecutivos con infección anal por viruela del mono en un solo centro de proctología entre el 16/6/2022 y el 26/7/2022. También se registró la asociación con infecciones de transmisión sexual (ITS) y el resultado.PACIENTES:Sesenta y cinco hombres de 39,6 [19,9-64,6] años con infección anal confirmada.PRINCIPALES MEDIDAS DE RESULTADO:Los síntomas anales y su gravedad se evaluaron clínicamente. Un resultado favorable consistió en una resolución completa de la manifestación clínica.RESULTADOS:La transmisión sexual se informó en 51 (78,4%) pacientes, de los cuales 63 (97%) eran hombres que tuvieron sexo con hombres. Veintiocho (43%) vivían con el VIH y 24 (36,9%) tomaban Emtricitabina/Tenofovir para profilaxis previa por exposición al VIH. Los síntomas anales aparecieron primero en 36 (55,4%) pacientes y la erupción cutánea u otros síntomas generales en 22 (33,8%). El tiempo de incubación fue de 6,9 [1-26] días. Los síntomas incluyeron ulceraciones perianales dolorosas (n = 42 pacientes, 64,6%), anales (n = 28, 43%), rectales (n = 25, 38,4%) y vesículas perianales (n = 24, 36,9%). Se observó proctitis en 49 (75,4%) pacientes. Fue leve en 20 (40,8%) e intensa en 29 (59,2%) y proctitis severa simulando supuración interesfinteriana alta en 4 (8,2%). Quince (23,1%) pacientes presentaban ITS concurrentes y 3 fueron hospitalizados. La resolución completa de los síntomas ocurrió dentro de los 12 días.LIMITACIONES:Estudio de un solo centro y durante corto período de tiempo.CONCLUSIÓN:Los síntomas proctológicos son frecuentes en el brote actual de la enfermedad de la viruela del mono, probablemente relacionados con la vía de transmisión. Las ulceraciones rectales que simulan una supuración interesfinteriana alta deben reconocerse para evitar una cirugía innecesaria. (Traducción-Dr. Fidel Ruiz Healy ).

Seroprevalence of Crimean-Congo hemorrhagic fever virus among people living with HIV in Brazzaville, Congo and among blood donors in Bamako, Mali.

Crimean-Congo hemorrhagic fever virus (CCHFV) is the causative agent of Crimean-Congo hemorrhagic fever (CCHF), a highly contagious and potentially fatal emerging disease. We assessed CCHFV seroprevalence by conducting a serological survey of two cohorts from Brazzaville, Congo and Bamako, Mali. We retrospectively screened 581 sera samples, including 352 from monitoring centers for people living with HIV (PLWH) in Brazzaville and 229 provided by the Blood Transfusion Center at Gabriel Touré Hospital in Bamako. An ELISA kit (ID Screen® CCHF Double Antigen Multi-species, Innovative Diagnostics) was used to detect total anti-CCHFV antibodies in serum. CCHFV seroprevalence was 0.6% in the PLWH cohort in Brazzaville, all in a peri­urban area near livestock/agriculture, and 1.75% in a cohort of blood donors in Bamako, half living in a peri­urban area near livestock/agriculture and the others performing risk-exposure activities, such as working as a butcher or with frequent rural travels. PLWH from Brazzaville were mostly female, older, and more highly educated, with a tertiary sector activity and living in an urban biotope without livestock/agricultural activities in the surroundings, in contrast to the blood donors of Bamako, who were younger and more likely to live in peri­urban/rural areas with livestock/agricultural activities in the surroundings. Despite a low CCHFV seroprevalence, our study indicates human contact with CCHFV in sub-urban areas of the capital cities of Congo and Mali associated with previously described CCHFV risk factors.

COVID-19 early curative treatments in kidney transplant recipients: is it really reasonable at the Omicron era?

Objective: Data about efficacy and safety of the latest COVID-19 treatments as nirmatrelvir/ritonavir (n/r) or Sotrovimab is scarce in solid organ transplant recipients in the Omicron era. This study aims at describing the outcome of kidney transplant recipients (KTRs) presenting Omicron infection according to their management: n/r, sotrovimab or no specific treatment. Patients and methods: We conducted a monocentric, retrospective observational study, including KTRs diagnosed Omicron infection between January and May 1st 2022 and compared their outcome (primary outcome defined as hospital admission for COVID-19 within a month after symptoms onset) according to early COVID-19 management. Results: Forty-five patients were included: 22 treated (12 n/r, 10 sotrovimab) and 23 with no specific treatment. The groups were statistically comparable. Two patients were admitted for COVID-19: one in each group, resulting in a non-different probability of the primary outcome at on month (p=0.9). Three patients presented tacrolimus overdose including two with acute kidney injury. Conclusions: There was no difference in outcome according to early therapeutic management: n/r, sotrovimab or no specific treatment. Our study both underlines a decreased severity of Omicron COVID-19 in KTRs (probably related to vaccinal immunity and decreased virulence of Omicron) and a potential severe adverse effects with n/r.

Objectif: Les données sur l'efficacité et la sécurité des derniers traitements de la Covid-19 sont peu nombreuses à l'ère du variant Omicron. Cette étude avait pour objectif de décrire l'évolution des transplantés rénaux (TR) présentant une infection à Omicron selon le traitement précoce reçu : nirmatrelvir/ritonavir (n/r), sotrovimab, ou pas de traitement. Patients et méthodes: Il s'agissait d'une étude monocentrique rétrospective observationnelle incluant tous les TR présentant une infection confirmée à Omicron entre le 1er janvier 2022 et le 1er mai 2022 et comparant leur évolution (critère de jugement principal : admission hospitalière pour Covid-19 à un mois du début des symptômes) selon leur prise en charge. Résultats: Quarante-cinq patients ont été inclus : 22 traités (12 n/r et 10 sotrovimab) et 23 non traités. Les groupes étaient statistiquement comparables. Seulement deux patients ont présenté le critère de jugement principal : un n/r et un non traité, avec une probabilité à un mois non différente (p = 0,9). Trois patients sur 12 ont en revanche présenté des surdosages en tacrolimus dans le groupe n/r, dont deux avec une insuffisance rénale aiguë. Conclusions: Dans les limites d'un petit effectif, nous n'avons pas montré de bénéfice au traitement précoce par n/r ou sotrovimab. On peut évoquer un effet de l'immunité vaccinale et une baisse de virulence du SARS-CoV-2. En revanche, les effets secondaires du n/r ne sont pas anodins avec des surdosages sévères malgré des protocoles de service précis. La balance bénéfice-risque de ces traitements doit être rediscutée.

Higher levels of SARS-CoV-2 genetic variation in immunocompromised patients: a retrospective case-control study.

BACKGROUND: A SARS-CoV-2 infection lasts longer in immunocompromised hosts than in immunocompetent patients. Prolonged infection is associated with a higher probability of selection for novel SARS-CoV-2 mutations, particularly in the spike protein, a critical target for vaccines and therapeutics. METHODS: From December 2020 to September 2022, respiratory samples from 444 immunocompromised patients and 234 healthcare workers positive for SARS-CoV-2, diagnosed at two hospitals in Paris, France, were analyzed using whole-genome sequencing using Nanopore technology. Custom scripts were developed to assess the SARS-CoV-2 genetic diversity between the two groups and within the host. RESULTS: Most infections were SARS-CoV-2 Delta or Omicron lineages. Viral genetic diversity was significantly higher in infections of immunocompromised patients than those of controls. Minor mutations were identified in viruses sequenced from immunocompromised individuals, which became signature mutations for newer SARS-CoV-2 variants as the epidemic progressed. Two patients were co-infected with Delta and Omicron variants. The follow-up of immunocompromised patients revealed that the SARS-CoV-2 genome evolution differed in the upper and lower respiratory tracts. CONCLUSIONS: This study found that SARS-CoV-2 infection in immunocompromised patients is associated with higher genetic diversity, which could lead to the emergence of new SARS-CoV-2 variants with possible immune evasion or different virulence characteristics.

Comparative Performance of Anyplex II HPV28 and Cobas 4800 Human Papillomavirus (HPV) Assays for High-Risk HPV Detection in Self-collected Anal Samples.

We compared 2 human papillomavirus (HPV) assays to detect the 14 high-risk HPV (hrHPV) genotypes in self-collected anal samples. We found a good agreement and similar performance to detect HPV-16, HPV-18, and the 12 other hrHPV genotypes. The global performance to detect the 14 hrHPV genotypes was not significantly different between the 2 assays.

In-hospital mortality of older patients with COVID-19 throughout the epidemic waves in the great Paris area: a multicenter cohort study.

BACKGROUND: Mortality is high in older patients hospitalized with COVID-19. Previous studies observed lower mortality during the Omicron wave, yet no data is available on older patients. The objective was to compare in-hospital mortality between the Omicron and previous waves in older patients hospitalized with COVID-19. METHODS: This retrospective observational multicenter cohort study used the Greater Paris University Hospitals Group's data warehouse (38 hospitals). Patients aged ≥ 75 years with a confirmed COVID-19 diagnosis and hospitalized from March 2020 to January 2022 were included. The study period was divided into five waves. The fifth wave (January 1st to 31st 2022) was considered as the Omicron wave as it was the predominant variant (≥ 50%), and was compared with waves 1 (March-July 2020), 2 (August-December 2020), 3 (January-June 2021) and 4 (July-December 2021). Primary outcome was in-hospital mortality. Secondary outcome was occurrence of ICU admission or in-hospital death. Multivariate logistic regression was performed, with a sensitivity analysis according to variant type. RESULTS: Of the 195,084 patients hospitalized with COVID-19, 19,909 patients aged ≥ 75 years were included (median age 85 [IQR 79-90] years, 53% women). Overall in-hospital mortality was 4,337 (22%), reaching 345 (17%) during wave 5. Waves 1 and 3 were significantly associated with increased in-hospital mortality in comparison with wave 5 (adjusted Odds Ratios aOR 1.42 [95%CI 1.21-1.66] and 1.56 [95%CI 1.33-1.83] respectively). Waves 1 to 3 were associated with an increased risk of occurrence of ICU admission or in-hospital death in comparison with wave 5: aOR 1.29 [95% CI 1.12 to 1.49] for wave 1, aOR 1.25 [95% CI 1.08 to 1.45] for wave 2 and aOR 1.56 [95% CI 1.36 to 1.79] for wave 3. Sensitivity analysis found that Omicron variant was associated with decreased mortality, in comparison with previous variants. CONCLUSIONS: Mortality was lower during the 5th Omicron wave in the older population, but remained high, implying that this variant could be considered as "milder" but not "mild". This persistently high mortality during the 5th Omicron wave highlights the importance of including older patients in clinical trials to confirm the benefit/risk balance of COVID-19 treatments in this fragile population.

Clinical phenotypes and outcomes associated with SARS-CoV-2 Omicron variants BA.2, BA.5 and BQ.1.1 in critically ill patients with COVID-19: a prospective, multicenter cohort study.

BACKGROUND: Despite current broad natural and vaccine-induced protection, a substantial number of patients infected with emerging SARS-CoV-2 variants (e.g., BF.7 and BQ.1.1) still experience severe COVID-19. Real-life studies investigating the impact of these variants on clinical outcomes of severe cases are currently not available. We performed a prospective multicenter observational cohort study. Adult patients with acute respiratory failure admitted between December 7, 2021 and December 15, 2022, in one of the 20 participating intensive care units (17 from the Greater Paris area and 3 from the North of France) were eligible for inclusion if they had SARS-CoV-2 infection confirmed by a positive reverse transcriptase-polymerase chain reaction (RT-PCR). Full-length SARS-CoV-2 genomes from all included patients were sequenced by means of next-generation sequencing. The primary endpoint of the study was day-28 mortality. RESULTS: The study included 158 patients infected with three groups of Omicron sublineages, including (i) BA.2 variants and their early sublineages referred as "BA.2" (n = 50), (ii) early BA.4 and BA.5 sublineages (including BA.5.1 and BA.5.2, n = 61) referred as "BA.4/BA.5", and (iii) recent emerging BA.5 sublineages (including BQ.1, BQ.1.1, BF.7, BE.1 and CE.1, n = 47) referred as "BQ.1.1". The clinical phenotype of BQ1.1-infected patients compared to earlier BA.2 and BA.4/BA.5 sublineages, showed more frequent obesity and less frequent immunosuppression. There was no significant difference between Omicron sublineage groups regarding the severity of the disease at ICU admission, need for organ failure support during ICU stay, nor day 28 mortality (21.7%, n = 10/47 in BQ.1.1 group vs 26.7%, n = 16/61 in BA.4/BA.5 vs 22.0%, n = 11/50 in BA.2, p = 0.791). No significant relationship was found between any SARS-CoV-2 substitution and/or deletion on the one hand and survival on the other hand over hospital follow-up. CONCLUSIONS: Critically-ill patients with Omicron BQ.1.1 infection showed a different clinical phenotype than other patients infected with earlier Omicron sublineage but no day-28 mortality difference.

Golgi localization of SARS-CoV-2 spike protein and interaction with furin in cerebral COVID-19 microangiopathy: a clue to the central nervous system involvement?

In a neuropathological series of 20 COVID-19 cases, we analyzed six cases (three biopsies and three autopsies) with multiple foci predominantly affecting the white matter as shown by MRI. The cases presented with microhemorrhages evocative of small artery diseases. This COVID-19 associated cerebral microangiopathy (CCM) was characterized by perivascular changes: arterioles were surrounded by vacuolized tissue, clustered macrophages, large axonal swellings and a crown arrangement of aquaporin-4 immunoreactivity. There was evidence of blood-brain-barrier leakage. Fibrinoid necrosis, vascular occlusion, perivascular cuffing and demyelination were absent. While no viral particle or viral RNA was found in the brain, the SARS-CoV-2 spike protein was detected in the Golgi apparatus of brain endothelial cells where it closely associated with furin, a host protease known to play a key role in virus replication. Endothelial cells in culture were not permissive to SARS-CoV-2 replication. The distribution of the spike protein in brain endothelial cells differed from that observed in pneumocytes. In the latter, the diffuse cytoplasmic labeling suggested a complete replication cycle with viral release, notably through the lysosomal pathway. In contrast, in cerebral endothelial cells the excretion cycle was blocked in the Golgi apparatus. Interruption of the excretion cycle could explain the difficulty of SARS-CoV-2 to infect endothelial cells in vitro and to produce viral RNA in the brain. Specific metabolism of the virus in brain endothelial cells could weaken the cell walls and eventually lead to the characteristic lesions of COVID-19 associated cerebral microangiopathy. Furin as a modulator of vascular permeability could provide some clues for the control of late effects of microangiopathy.

Three to four mRNA COVID-19 vaccines in multiple sclerosis patients on immunosuppressive drugs: Seroconversion and variant neutralization.

BACKGROUND AND PURPOSE: An enhanced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine regimen could improve humoral vaccine response in patients with multiple sclerosis (MS) treated by anti-CD20. The aim was to evaluate the serological response and the neutralizing activity after BNT162b2 primary and booster vaccination in MS patients, including patients on anti-CD20 receiving a primary vaccine regimen enhanced with three injections. METHODS: In this prospective longitudinal cohort study of 90 patients (47 on anti-CD20, 10 on fingolimod, 33 on natalizumab, dimethylfumarate or teriflunomide), anti-SARS-CoV-2 receptor binding domain (RBD) immunoglobulin G antibodies were quantified and their neutralization capacity was evaluated by enzyme-linked immunosorbent assay (GenScript) and a virus neutralization test against B.1 historical strain, Delta and Omicron variants, before and after three to four BNT162b2 injections. RESULTS: After the primary vaccination scheme, the anti-RBD positivity rate was strongly decreased in patients on anti-CD20 (28% [15%; 44%] after two shots, 45% [29%; 62%] after three shots) and fingolimod (50% [16%; 84%]) compared to other treatments (100% [90%; 100%]). Neutralization activity was also decreased in patients on anti-CD20 and fingolimod, and notably low for the Omicron variant in all patients (0%-22%). Delayed booster vaccination was performed in 54 patients, leading to a mild increase of anti-RBD seropositivity in patients on anti-CD20 although it was still lower compared to other treatments (65% [43%; 84%] vs. 100% [87%; 100%] respectively). After a booster, Omicron neutralization activity remained low on anti-CD20 and fingolimod treated patients but was strongly increased in patients on other treatments (91% [72%; 99%]). DISCUSSION: In MS patients on anti-CD20, an enhanced primary vaccination scheme moderately increased anti-RBD seropositivity and anti-RBD antibody titre, but neutralization activity remained modest even after a fourth booster injection. TRIAL REGISTRATION INFORMATION: COVIVAC-ID, NCT04844489, first patient included on 20 April 2021.

Complement-dependent mpox-virus-neutralizing antibodies in infected and vaccinated individuals.

Mpox virus (MPXV) caused a multi-country outbreak in non-endemic areas in 2022. Following historic success of smallpox vaccination with vaccinia virus (VACV)-based vaccines, the third generation modified vaccinia Ankara (MVA)-based vaccine was used as prophylaxis for MPXV, but its effectiveness remains poorly characterized. Here, we applied two assays to quantify neutralizing antibodies (NAbs) in sera from control, MPXV-infected, or MVA-vaccinated individuals. Various levels of MVA NAbs were detected after infection, historic smallpox, or recent MVA vaccination. MPXV was minimally sensitive to neutralization. However, addition of complement enhanced detection of responsive individuals and NAb levels. Anti-MVA and -MPXV NAbs were observed in 94% and 82% of infected individuals, respectively, and 92% and 56% of MVA vaccinees, respectively. NAb titers were higher in individuals born before 1980, highlighting the impact of historic smallpox vaccination on humoral immunity. Altogether, our results indicate that MPXV neutralization is complement dependent and uncover mechanisms underlying vaccine effectiveness.

Corrigendum: XAV-19, a swine glyco-humanized polyclonal antibody against SARS-CoV-2 spike receptor-binding domain, targets multiple epitopes and broadly neutralizes variants.

[This corrects the article DOI: 10.3389/fimmu.2021.761250.].

Severity of SARS-CoV-2 Omicron variant infection in heart transplant recipients.

SARS-CoV-2 Omicron variant was first detected in France mid-November 2021 in wastewater treatment plants while cases started to increase at the beginning of December. The maximum incidence occurred in mid-January 2022. The Omicron wave spread rapidly throughout France in general population with lower case-fatality rate compared with previous waves. Little is known about infection with Omicron variant in heart transplant (HT) recipients. In this study, we examined incidence and mortality rate of COVID-19 in the general population and among 1,263 HT recipients during the period from June, 2021 to February, 2022, described characteristics of HT recipients infected with SARS-CoV-2 during Omicron (December 1st, 2021-February 7, 2022) and Delta (June 1st- November 30, 2021) periods, and compared hospital course of HT recipients with Omicron and Delta variant infection. Our findings contrast with the reported lower severity for Omicron variant infection compared with Delta variant infection in immunocompetent individuals.

Viral loads in clinical samples of men with monkeypox virus infection: a French case series.

BACKGROUND: Monkeypox virus (MPXV) is currently spreading among men who have sex with men, outside of sub-Saharan Africa, and close contact during sex seems to be one of the key pathways of viral transmission in the current outbreak. Our aim was to describe the distribution of MPXV in the human body, as it might play a role in its dissemination through sexual contact. METHODS: The study population in this case series consisted of patients with confirmed MPXV infection attending the Pitié-Salpêtrière Hospital (Paris, France), who had been sampled from multiple anatomical sites, including skin, anus, throat, blood, urine, and semen, at diagnosis and 2 weeks later. We compared the proportion of positive samples and MPXV viral loads (given as PCR cycle thresholds [Ct]) between anatomical sites, and between day 0 (D0) and D14. FINDINGS: Overall, 356 samples were collected between May 20 and June 13, 2022, from 50 men with a median age of 34 years (IQR 29-40). 22 (44%) of the 50 men were classified as HIV-negative on day (D)0, and 22 (44%) were living with HIV. At D0, MPXV detection was more frequent from skin (44 [88%] of 50), anus (30 [71%] of 42), and throat (36 [77%] of 47) than from blood (13 [29%] of 45), urine (nine [22%] of 41), or semen (13 [54%] of 24). Viral loads were significantly higher from skin lesions (Ct 19·8) and anal samples (Ct 20·9) than from throat (Ct 27·2), blood (Ct 32·8), urine (31·1), or semen samples (Ct 27·8). When analysing the 107 samples taken from 24 patients at D14, the proportion of positive samples strongly decreased between D0 and D14 at all sites: skin (four [22%] of 18), anus (two [9%] of 22), throat (none of 21), blood (one [5%] of 21), urine (none of 14), and semen (two [9%] of 11). INTERPRETATION: These data contribute to a better understanding of how the virus might spread between sexual partners over a relatively short period of time. High MPXV viral loads from skin and mucosa, including genital and anal sites, suggest that transmission most likely occurs through direct body contact rather than through the respiratory route or contact with body fluids, which should help to refine the prevention messages delivered to individuals most exposed to the virus. FUNDING: None.

Prolonged replication of BA.1 and BA.2 Omicron lineages compared to Delta variant in nasopharyngeal samples from COVID-19 patients.

OBJECTIVES: We aimed to characterize and compare the viral loads (VL) of the Omicron BA.1 and BA.2 lineages and the Delta variant in nasopharyngeal samples from newly diagnosed COVID-19 patients and their kinetics over time. PATIENTS AND METHODS: The kinetics of the VL were measured on the CT data from 215 SARS-CoV-2 positive patients who presented at least two positive PCRs a day apart and were screened for SARS-CoV-2 viral lineages. RESULTS: We observed no significant difference in median CT value during the first diagnostic test between the Delta variant and the two Omicron lineages. However, the kinetics of CT decreases for the BA.1 and BA.2 lineage were significantly lengthier in time than the kinetics for the Delta variant. The BA.2 lineage presented lower median CT value (-2 CT) (inversely proportional to the VL) than the BA.1 lineage. CONCLUSIONS: BA.2 Omicron lineage presented higher VL than BA.1 Omicron lineage at diagnostic. Omicron BA.1 and BA.2 lineages have more prolonged replication than the Delta variant.

SARS-CoV-2 Neutralizing Responses in Various Populations, at the Time of SARS-CoV-2 Variant Virus Emergence: Evaluation of Two Surrogate Neutralization Assays in Front of Whole Virus Neutralization Test.

The SARS-CoV-2 neutralizing antibodies response is the best indicator of effective protection after infection and/or vaccination, but its evaluation requires tedious cell-based experiments using an infectious virus. We analyzed, in 105 patients with various histories of SARS-CoV-2 infection and/or vaccination, the neutralizing response using a virus neutralization test (VNT) against B.1, Alpha, Beta and Omicron variants, and compared the results with two surrogate assays based on antibody-mediated blockage of the ACE2-RBD interaction (Lateral Flow Boditech and ELISA Genscript). The strongest response was observed for recovered COVID-19 patients receiving one vaccine dose. Naïve patients receiving 2 doses of mRNA vaccine also demonstrate high neutralization titers against B.1, Alpha and Beta variants, but only 34.3% displayed a neutralization activity against the Omicron variant. On the other hand, non-infected patients with half vaccination schedules displayed a weak and inconstant activity against all isolates. Non-vaccinated COVID-19 patients kept a neutralizing activity against B.1 and Alpha up to 12 months after recovery but a decreased activity against Beta and Omicron. Both surrogate assays displayed a good correlation with the VNT. However, an adaptation of the cut-off positivity was necessary, especially for the most resistant Beta and Omicron variants. We validated two simple and reliable surrogate neutralization assays, which may favorably replace cell-based methods, allowing functional analysis on a larger scale.