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1.
Nat Med ; 2022 Mar 23.
Article in English | MEDLINE | ID: covidwho-1758268

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 Omicron BA.1 sublineage has been supplanted in many countries by the BA.2 sublineage. BA.2 differs from BA.1 by about 21 mutations in its spike. In this study, we first compared the sensitivity of BA.1 and BA.2 to neutralization by nine therapeutic monoclonal antibodies (mAbs). In contrast to BA.1, BA.2 was sensitive to cilgavimab, partly inhibited by imdevimab and resistant to adintrevimab and sotrovimab. We then analyzed sera from 29 immunocompromised individuals up to 1 month after administration of Ronapreve (casirivimab and imdevimab) and/or Evusheld (cilgavimab and tixagevimab) antibody cocktails. All treated individuals displayed elevated antibody levels in their sera, which efficiently neutralized the Delta variant. Sera from Ronapreve recipients did not neutralize BA.1 and weakly inhibited BA.2. Neutralization of BA.1 and BA.2 was detected in 19 and 29 out of 29 Evusheld recipients, respectively. As compared to the Delta variant, neutralizing titers were more markedly decreased against BA.1 (344-fold) than BA.2 (nine-fold). We further report four breakthrough Omicron infections among the 29 individuals, indicating that antibody treatment did not fully prevent infection. Collectively, BA.1 and BA.2 exhibit noticeable differences in their sensitivity to therapeutic mAbs. Anti-Omicron neutralizing activity of Ronapreve and, to a lesser extent, that of Evusheld is reduced in patients' sera.

2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-330085

ABSTRACT

The SARS-CoV-2 Omicron BA.1 variant has been supplanted in many countries by the BA.2 sub-lineage. BA.2 differs from BA.1 by about 21 mutations in its spike. Human anti-spike monoclonal antibodies (mAbs) are used for prevention or treatment of COVID-19. However, the capacity of therapeutic mAbs to neutralize BA.1 and BA.2 remains poorly characterized. Here, we first compared the sensitivity of BA.1 and BA.2 to neutralization by 9 therapeutic mAbs. In contrast to BA.1, BA.2 was sensitive to Cilgavimab, partly inhibited by Imdevimab and resistant to Adintrevimab and Sotrovimab. Two combinations of mAbs, Ronapreve (Casirivimab + Imdevimab) and Evusheld (Cilgavimab + Tixagevimab), are indicated as a pre-exposure prophylaxis in immunocompromised persons at risk of severe disease. We analyzed sera from 29 such individuals, up to one month after administration of Ronapreve and/or Evusheld. After treatment, all individuals displayed elevated antibody levels in their sera and neutralized Delta with high titers. Ronapreve recipients did not neutralize BA.1 and weakly impaired BA.2. With Evusheld, neutralization of BA.1 and BA.2 was detected in 19 and 29 out of 29 patients, respectively. As compared to Delta, titers were more severely decreased against BA.1 (344-fold) than BA.2 (9-fold). We further report 4 breakthrough Omicron infections among the 29 participants. Therefore, BA.1 and BA.2 exhibit noticeable differences in their sensitivity to therapeutic mAbs. Anti-Omicron activity of Ronapreve, and to a lesser extent that of Evusheld, is reduced in patients’ sera, a phenomenon associated with decreased clinical efficacy.

3.
iScience ; : 104075, 2022 Mar 14.
Article in English | MEDLINE | ID: covidwho-1739820

ABSTRACT

It has been suggested that during the period of respiratory worsening of severe COVID-19 patients, viral replication plays a less important role than inflammation. Using the droplet-based digital PCR (ddPCR) for precise quantification of plasma SARS-CoV-2 viral load (SARS-CoV-2 RNAemia), we investigated the relationship between plasma viral load, comorbidities and mortality of 122 critically ill COVID-19 patients. SARS-CoV-2 RNAemia was detected by ddPCR in 90 (74%) patients, ranging from 70 to 213,152 copies per ml. A high (>1 000 copies/ml) or very high (>10 000 copies/ml) SARS-Cov-2 RNAemia was observed in 46 patients (38%), of which 26 were diabetic. Diabetes was independently associated with a higher SARS-CoV-2 RNAemia. In multivariable logistic regression models, SARS-CoV-2 RNAemia was strongly and independently associated with day-60 mortality. Early initiation of antiviral therapies might be considered in COVID-19 critically ill patients with high RNAemia.

4.
EBioMedicine ; 77: 103934, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1739673

ABSTRACT

BACKGROUND: SARS-CoV-2 lineages are continuously evolving. As of December 2021, the AY.4.2 Delta sub-lineage represented 20 % of sequenced strains in the UK and had been detected in dozens of countries. It has since then been supplanted by Omicron. The AY.4.2 spike displays three additional mutations (T95I, Y145H and A222V) in the N-terminal domain when compared to the original Delta variant (B.1.617.2) and remains poorly characterized. METHODS: We compared the Delta and the AY.4.2 spikes, by assessing their binding to antibodies and ACE2 and their fusogenicity. We studied the sensitivity of an authentic AY.4.2 viral isolate to neutralizing antibodies. FINDINGS: The AY.4.2 spike exhibited similar binding to all the antibodies and sera tested, and similar fusogenicity and binding to ACE2 than the ancestral Delta spike. The AY.4.2 virus was slightly less sensitive than Delta to neutralization by a panel of monoclonal antibodies; noticeably, the anti-RBD Imdevimab showed incomplete neutralization. Sensitivity of AY.4.2 to sera from vaccinated individuals was reduced by 1.3 to 3-fold, when compared to Delta. INTERPRETATION: Our results suggest that mutations in the NTD remotely impair the efficacy of anti-RBD antibodies. The spread of AY.4.2 was not due to major changes in spike fusogenicity or ACE2 binding, but more likely to a partially reduced neutralization sensitivity. FUNDING: The work was funded by Institut Pasteur, Fondation pour la Recherche Médicale, Urgence COVID-19 Fundraising Campaign of Institut Pasteur, ANRS, the Vaccine Research Institute, Labex IBEID, ANR/FRM Flash Covid PROTEO-SARS-CoV-2 and IDISCOVR.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Monoclonal, Humanized , Antibodies, Viral , Humans , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Envelope Proteins
5.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-306787

ABSTRACT

Background: SARS-CoV-2 induces a humoral response with seroconversion occurring within the first weeks after COVID-19 disease. Those antibodies exert a neutralizing activity against SARS-CoV-2, whose evolution overtime after COVID-19 is however unknown.Methods: In this monocentric prospective study, sera of 107 patients hospitalized with COVID-19 were collected at 3 months and 6 months post-infection. We performed quantitative neutralization experiments on top of high-throughput serological assays evaluating anti-Spike (S) and anti-Nucleocapsid (NP) IgG.Findings: Levels of sero-neutralization decreased significantly over study time, as well as IgG rates. After 6 months, 2.8% of the patients had a negative serological status for both anti-S and anti-NP IgG. However, all sera had a persistent and effective neutralizing effect on SARS-CoV-2 neutralizing assays. IgG levels correlated with sero-neutralization and this correlation was stronger for anti-S than for anti-NP antibodies. The level of sero-neutralization quantified at 6 months correlated with markers of initial severity, notably admission in intensive care units and the need for mechanical invasive ventilation.Interpretation: Decrease of IgG rates and serological assays becoming negative did not imply loss of neutralizing capacity in our patients. Those results are encouraging and in favor of sustained humoral response for at least 6 months in patients previously hospitalized for COVID-19, which will have to be considered in global deployment of vaccination strategy.Trial Registration: The French Covid cohort (NCT04262921)Funding Statement: The French COVID cohort is funding by the REACTing (REsearch & ACtion emergING infectious diseases) consortium and by a grant of the French Ministry of Health (PHRC n°20-0424).Outside the submitted work, JSH is supported by AP-HP, INSERM, the French National Research Agency (NADHeart ANR-17-CE17-0015-02, PACIFIC ANR-18-CE14-0032-01, CORRECT_LMNA ANR-19-CE17-0013-02), the ERA-Net-CVD (ANR-16-ECVD-0011-03, Clarify project), Fédération Française de Cardiologie, the Fondation pour la Recherche Médicale, and by a grant from the Leducq Foundation (18CVD05), and is coordinating a French PIA Project (2018-PSPC-07, PACIFIC-preserved, BPIFrance) and a University Research Federation against heart failure (FHU2019, PREVENT_Heart Failure). JG reports personal fees from ViiV Healthcare, Gilead Science, Janssen Cilag, and research grants from Gilead Sciences, MSD and ViiV Healthcare, outside the submitted work.Declaration of Interests: Authors have nothing to disclose. There are no relationships with industry.Ethics Approval Statement: The French Covid cohort (NCT04262921) is a prospective multi-center observational cohort sponsored by Inserm which was authorized by the French Ethics Committee CPP Ile-de-France VI (ID RCB:2020-A00256-33).

6.
Euro Surveill ; 27(6)2022 Feb.
Article in English | MEDLINE | ID: covidwho-1686391

ABSTRACT

BackgroundThe COVID-19 pandemic has led to an unprecedented daily use of RT-PCR tests. These tests are interpreted qualitatively for diagnosis, and the relevance of the test result intensity, i.e. the number of quantification cycles (Cq), is debated because of strong potential biases.AimWe explored the possibility to use Cq values from SARS-CoV-2 screening tests to better understand the spread of an epidemic and to better understand the biology of the infection.MethodsWe used linear regression models to analyse a large database of 793,479 Cq values from tests performed on more than 2 million samples between 21 January and 30 November 2020, i.e. the first two pandemic waves. We performed time series analysis using autoregressive integrated moving average (ARIMA) models to estimate whether Cq data information improves short-term predictions of epidemiological dynamics.ResultsAlthough we found that the Cq values varied depending on the testing laboratory or the assay used, we detected strong significant trends associated with patient age, number of days after symptoms onset or the state of the epidemic (the temporal reproduction number) at the time of the test. Furthermore, knowing the quartiles of the Cq distribution greatly reduced the error in predicting the temporal reproduction number of the COVID-19 epidemic.ConclusionOur results suggest that Cq values of screening tests performed in the general population generate testable hypotheses and help improve short-term predictions for epidemic surveillance.


Subject(s)
COVID-19 , SARS-CoV-2 , France/epidemiology , Humans , Pandemics , Reverse Transcriptase Polymerase Chain Reaction
7.
Am J Transplant ; 2022 Feb 12.
Article in English | MEDLINE | ID: covidwho-1685185

ABSTRACT

Immunocompromised patients may experience prolonged viral shedding after their initial SARS-CoV-2 infection, however, symptomatic relapses after remission currently remain rare. We herein describe a severe COVID-19 relapse case of a kidney transplant recipient (KTR) following rituximab therapy, 3 months after a moderate COVID-19 infection, despite viral clearance after recovery of the first episode. During the clinical relapse, the diagnosis was established on a broncho-alveolar lavage specimen (BAL) by RT-PCR. The infectivity of the BAL sample was confirmed on a cell culture assay. Whole genome sequencing confirmed the presence of an identical stain (Clade 20A). However, it had an acquired G142D mutation and a larger deletion of 3-amino-acids at position 143-145. These mutations located within the N-terminal domain are suggested to play a role in viral entry. The diagnosis of a COVID-19 relapse should be considered in the setting of unexplained persistent fever and/or respiratory symptoms in KTRs (especially for those after rituximab therapy), even in patients with previous negative naso-pharyngeal SARS-CoV-2 PCR.

9.
Ann Rheum Dis ; 81(5): 720-728, 2022 May.
Article in English | MEDLINE | ID: covidwho-1622018

ABSTRACT

OBJECTIVES: The emergence of strains of SARS-CoV-2 exhibiting increase viral fitness and immune escape potential, such as the Delta variant (B.1.617.2), raises concerns in immunocompromised patients. We aimed to evaluate seroconversion, cross-neutralisation and T-cell responses induced by BNT162b2 in immunocompromised patients with systemic inflammatory diseases. METHODS: Prospective monocentric study including patients with systemic inflammatory diseases and healthcare immunocompetent workers as controls. Primary endpoints were anti-spike antibodies levels and cross-neutralisation of Alpha and Delta variants after BNT162b2 vaccine. Secondary endpoints were T-cell responses, breakthrough infections and safety. RESULTS: Sixty-four cases and 21 controls not previously infected with SARS-CoV-2 were analysed. Kinetics of anti-spike IgG after BNT162b2 vaccine showed lower and delayed induction in cases, more pronounced with rituximab. Administration of two doses of BNT162b2 generated a neutralising response against Alpha and Delta in 100% of controls, while sera from only one of rituximab-treated patients neutralised Alpha (5%) and none Delta. Other therapeutic regimens induced a partial neutralising activity against Alpha, even lower against Delta. All controls and cases except those treated with methotrexate mounted a SARS-CoV-2 specific T-cell response. Methotrexate abrogated T-cell responses after one dose and dramatically impaired T-cell responses after two doses of BNT162b2. Third dose of vaccine improved immunogenicity in patients with low responses. CONCLUSION: Rituximab and methotrexate differentially impact the immunogenicity of BNT162b2, by impairing B-cell and T-cell responses, respectively. Delta fully escapes the humoral response of individuals treated with rituximab. These findings support efforts to improve BNT162b2 immunogenicity in immunocompromised individuals (ClinicalTrials.gov number, NCT04870411).


Subject(s)
COVID-19 , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Immunocompromised Host , Immunogenicity, Vaccine , Methotrexate , Prospective Studies , Rituximab , SARS-CoV-2
10.
Nature ; 602(7898): 671-675, 2022 02.
Article in English | MEDLINE | ID: covidwho-1616994

ABSTRACT

The SARS-CoV-2 Omicron variant was first identified in November 2021 in Botswana and South Africa1-3. It has since spread to many countries and is expected to rapidly become dominant worldwide. The lineage is characterized by the presence of around 32 mutations in spike-located mostly in the N-terminal domain and the receptor-binding domain-that may enhance viral fitness and enable antibody evasion. Here we isolated an infectious Omicron virus in Belgium from a traveller returning from Egypt. We examined its sensitivity to nine monoclonal antibodies that have been clinically approved or are in development4, and to antibodies present in 115 serum samples from COVID-19 vaccine recipients or individuals who have recovered from COVID-19. Omicron was completely or partially resistant to neutralization by all monoclonal antibodies tested. Sera from recipients of the Pfizer or AstraZeneca vaccine, sampled five months after complete vaccination, barely inhibited Omicron. Sera from COVID-19-convalescent patients collected 6 or 12 months after symptoms displayed low or no neutralizing activity against Omicron. Administration of a booster Pfizer dose as well as vaccination of previously infected individuals generated an anti-Omicron neutralizing response, with titres 6-fold to 23-fold lower against Omicron compared with those against Delta. Thus, Omicron escapes most therapeutic monoclonal antibodies and, to a large extent, vaccine-elicited antibodies. However, Omicron is neutralized by antibodies generated by a booster vaccine dose.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/virology , Immune Evasion/immunology , Immunization, Secondary , SARS-CoV-2/immunology , Adult , Antibodies, Monoclonal/immunology , /immunology , Belgium , COVID-19/immunology , COVID-19/transmission , /immunology , Convalescence , Female , Humans , Male , Mutation , Neutralization Tests , Phylogeny , SARS-CoV-2/classification , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Travel
11.
PLoS One ; 17(1): e0262258, 2022.
Article in English | MEDLINE | ID: covidwho-1606499

ABSTRACT

Although patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A, influenza B and respiratory syncytial virus (RSV) show comparable or very similar manifestations, the therapeutic approaches of these respiratory viral infections are different, which requires an accurate diagnosis. Recently, the novel multiplex real-time reverse transcription-polymerase chain reaction assay AMPLIQUICK® Respiratory Triplex (BioSynex SA, Illkirch-Graffenstaden, France) allows simultaneous detection and differentiation of SARS-CoV-2, influenza A, influenza B, and RSV in respiratory tract samples. We herein evaluated the performance of the AMPLIQUICK® Respiratory Triplex for the detection of the four viruses in respiratory specimens, using Allplex™ Respiratory Panel 1 and 2019-nCoV assays (Seegene, Seoul, Korea) as reference comparator assays. A total of 359 archived predetermined respiratory samples, including 83, 145, 19 and 95 positive specimens for SARS-CoV-2, influenza A, influenza B and RSV respectively, were included. The AMPLIQUICK® Respiratory Triplex showed high concordance with the reference assays, with an overall agreement for SARS-CoV-2, influenza A, influenza B, and RSV at 97.6%, 98.8%, 98.3% and 100.0%, respectively, and high κ values ranging from 0.93 to 1.00, indicating an almost perfect agreement between assays. Furthermore, high correlations of cycle threshold (Ct) values were observed for positive samples of the four viruses between the AMPLIQUICK® Respiratory Triplex and comparator assays, with an overall high agreement between Ct values assessed by Bland-Altman analyses. In conclusion, these observations demonstrate that the multiplex AMPLIQUICK® Respiratory Triplex is a reliable assay for the qualitative detection and differentiation of SARS-CoV-2, influenza A, influenza B, and RSV in respiratory specimens, which may prove useful for streamlining diagnostics during the winter influenza-seasons.


Subject(s)
COVID-19/diagnosis , Influenza, Human/diagnosis , Multiplex Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/methods , Respiratory Syncytial Virus Infections/diagnosis , COVID-19/virology , Humans , Influenza, Human/virology , Molecular Diagnostic Techniques , Nasopharynx/virology , Respiratory Syncytial Virus Infections/virology , Retrospective Studies , Sensitivity and Specificity
12.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296907

ABSTRACT

The SARS-CoV-2 Omicron variant was first identified in November 2021 in Botswana and South Africa. It has in the meantime spread to many countries and is expected to rapidly become dominant worldwide. The lineage is characterized by the presence of about 32 mutations in the Spike, located mostly in the N-terminal domain (NTD) and the receptor binding domain (RBD), which may enhance viral fitness and allow antibody evasion. Here, we isolated an infectious Omicron virus in Belgium, from a traveller returning from Egypt. We examined its sensitivity to 9 monoclonal antibodies (mAbs) clinically approved or in development, and to antibodies present in 90 sera from COVID-19 vaccine recipients or convalescent individuals. Omicron was totally or partially resistant to neutralization by all mAbs tested. Sera from Pfizer or AstraZeneca vaccine recipients, sampled 5 months after complete vaccination, barely inhibited Omicron. Sera from COVID-19 convalescent patients collected 6 or 12 months post symptoms displayed low or no neutralizing activity against Omicron. Administration of a booster Pfizer dose as well as vaccination of previously infected individuals generated an anti-Omicron neutralizing response, with titers 5 to 31 fold lower against Omicron than against Delta. Thus, Omicron escapes most therapeutic monoclonal antibodies and to a large extent vaccine-elicited antibodies.

13.
Clin Infect Dis ; 2021 Dec 11.
Article in English | MEDLINE | ID: covidwho-1566003

ABSTRACT

BACKGROUND: Approximately 15-30% of hospitalized COVID-19 patients develop acute respiratory distress syndrome, systemic tissue injury, and/or multi-organ failure leading to death in around 45% of cases. There is a clear need for biomarkers which quantify tissue injury, predict clinical outcomes and guide the clinical management of hospitalized COVID-19 patients. METHODS: We herein report the quantification by droplet-based digital PCR (ddPCR) of the SARS-CoV-2 RNAemia and the plasmatic release of a ubiquitous human intracellular marker, the ribonuclease P (RNase P) in order to evaluate tissue injury and cell lysis in the plasma of 139 COVID-19 hospitalized patients at admission. RESULTS: We confirmed that SARS-CoV-2 RNAemia was associated with clinical severity of COVID-19 patients. In addition, we showed that plasmatic RNase P RNAemia at admission was also highly correlated with disease severity (P<0.001) and invasive mechanical ventilation status (P<0.001) but not with pulmonary severity. Altogether, these results indicate a consequent cell lysis process in severe and critical patients but not systematically due to lung cell death. Finally, the plasmatic RNase P RNA value was also significantly associated with overall survival. CONCLUSION: Viral and ubiquitous blood biomarkers monitored by ddPCR could be useful for the clinical monitoring and the management of hospitalized COVID-19 patients. Moreover, these results could pave the way for new and more personalized circulating biomarkers in COVID-19, and more generally in infectious diseases, specific from each patient organ injury profile.

14.
Clin Infect Dis ; 73(9): e2890-e2897, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1500985

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global public health problem that has already caused more than 662 000 deaths worldwide. Although the clinical manifestations of COVID-19 are dominated by respiratory symptoms, some patients present other severe damage such as cardiovascular, renal and liver injury, and/or multiple organ failure, suggesting a spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in blood. Recent ultrasensitive polymerase chain reaction (PCR) technology now allows absolute quantification of nucleic acids in plasma. We intend to use the droplet-based digital PCR technology to obtain sensitive detection and precise quantification of plasma SARS-CoV-2 viral load (SARS-CoV-2 RNAemia) in hospitalized COVID-19 patients. METHODS: Fifty-eight consecutive COVID-19 patients with pneumonia 8 to 12 days after onset of symptoms and 12 healthy controls were analyzed. Disease severity was categorized as mild to moderate in 17 patients, severe in 16, and critical in 26. Plasma SARS-CoV-2 RNAemia was quantified by droplet digital Crystal Digital PCR next-generation technology (Stilla Technologies, Villejuif, France). RESULTS: Overall, SARS-CoV-2 RNAemia was detected in 43 (74.1%) patients. Prevalence of positive SARS-CoV-2 RNAemia correlated with disease severity, ranging from 53% in mild-to-moderate patients to 88% in critically ill patients (P = .036). Levels of SARS-CoV-2 RNAemia were associated with severity (P = .035). Among 9 patients who experienced clinical deterioration during follow-up, 8 had positive SARS-CoV-2 RNAemia at baseline, whereas only 1 critical patient with undetectable SARS-CoV-2 RNAemia at the time of analysis died at day 27. CONCLUSION: SARS-CoV-2 RNAemia measured by droplet-based digital PCR constitutes a promising prognosis biomarker in COVID-19 patients.


Subject(s)
COVID-19 , SARS-CoV-2 , Critical Illness , Humans , RNA, Viral , Severity of Illness Index
15.
J Clin Virol ; 145: 104999, 2021 12.
Article in English | MEDLINE | ID: covidwho-1472030

ABSTRACT

OBJECTIVES: Risk of reinfection with SARS-CoV-2 among health-care workers (HCWs) is unknown. We assessed the incidence rate of SARS-CoV-2 reinfection in the real-life setting of a longitudinal observational cohort of HCWs from the Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, France, during the first and second waves of COVID-19 epidemic. METHODS: From March to December 2020, HCWs were subjected to molecular and serology testing of SARS-CoV-2. Reinfection was defined as a positive test result during the first wave, either by serology or PCR, followed by a positive PCR during the second wave. Evolution of COVID-19 status of HWCs was assessed by a Sankey diagram. RESULTS: A total of 7765 tests (4579 PCR and 3186 serology) were carried out and 4168 HCWs had at least one test result during the follow-up period with a positivity rate of 15.9%. No case of reinfection during the second wave could be observed among 102 positive HCWs of the first wave, nor among 175 HCWs found positive by PCR during the second wave who were negative during the first wave. CONCLUSIONS: SARS-CoV-2 reinfection was not observed among HCWs, suggesting a protective immunity against reinfection that lasts at least 8 months post infection.


Subject(s)
COVID-19 , SARS-CoV-2 , Health Personnel , Hospitals , Humans , Prospective Studies , Reinfection
16.
EBioMedicine ; 73: 103637, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1471944

ABSTRACT

BACKGROUND: The dynamics of SARS-CoV-2 alpha variant shedding and immune responses at the nasal mucosa remain poorly characterised. METHODS: We measured infectious viral release, antibodies and cytokines in 426 PCR+ nasopharyngeal swabs from individuals harboring non-alpha or alpha variants. FINDINGS: With both lineages, viral titers were variable, ranging from 0 to >106 infectious units. Rapid antigenic diagnostic tests were positive in 94% of samples with infectious virus. 68 % of individuals carried infectious virus within two days after onset of symptoms. This proportion decreased overtime. Viable virus was detected up to 14 days. Samples containing anti-spike IgG or IgA did not generally harbor infectious virus. Ct values were slightly but not significantly lower with alpha. This variant was characterized by a fast decrease of infectivity overtime and a marked release of 13 cytokines (including IFN-b, IP-10 and IL-10). INTERPRETATION: The alpha variant displays modified viral decay and cytokine profiles at the nasopharyngeal mucosae during symptomatic infection. FUNDING: This retrospective study has been funded by Institut Pasteur, ANRS, Vaccine Research Institute, Labex IBEID, ANR/FRM and IDISCOVR, Fondation pour la Recherche Médicale.


Subject(s)
Cytokines/metabolism , Nasopharynx/virology , SARS-CoV-2/isolation & purification , Adult , Aged , Antibodies, Viral/metabolism , COVID-19/pathology , COVID-19/virology , Female , Humans , Immunoglobulin A/metabolism , Immunoglobulin G/metabolism , Male , Middle Aged , Retrospective Studies
18.
Clin Infect Dis ; 73(6): e1337-e1344, 2021 09 15.
Article in English | MEDLINE | ID: covidwho-1411827

ABSTRACT

BACKGROUND: Humoral response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurs within the first weeks after coronavirus disease 2019 (COVID-19). Those antibodies exert a neutralizing activity against SARS-CoV-2, whose evolution over time after COVID-19 as well as efficiency against novel variants are poorly characterized. METHODS: In this prospective study, sera of 107 patients hospitalized with COVID-19 were collected at 3 and 6 months postinfection. We performed quantitative neutralization experiments on top of high-throughput serological assays evaluating anti-spike (S) and anti-nucleocapsid (NP) immunoglobulin G (IgG). RESULTS: Levels of seroneutralization and IgG rates against the ancestral strain decreased significantly over time. After 6 months, 2.8% of the patients had a negative serological status for both anti-S and anti-NP IgG. However, all sera had a persistent and effective neutralizing effect against SARS-CoV-2. IgG levels correlated with seroneutralization, and this correlation was stronger for anti-S than for anti-NP antibodies. The level of seroneutralization quantified at 6 months correlated with markers of initial severity, notably admission to intensive care units and the need for mechanical invasive ventilation. In addition, sera collected at 6 months were tested against multiple SARS-CoV-2 variants and showed efficient neutralizing effects against the D614G, B.1.1.7, and P.1 variants but significantly weaker activity against the B.1.351 variant. CONCLUSIONS: Decrease in IgG rates and serological assays becoming negative did not imply loss of neutralizing capacity. Our results indicate a sustained humoral response against the ancestral strain and the D614G, B.1.1.7, and P.1 variants for at least 6 months in patients previously hospitalized for COVID-19. A weaker protection was, however, observed for the B.1.351 variant.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , Hospitalization , Humans , Prospective Studies , Spike Glycoprotein, Coronavirus
20.
Open Forum Infect Dis ; 8(8): ofab369, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1352260

ABSTRACT

Cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) acquisition after vaccination with BNT162b2 have been described, but the risk of secondary transmission from fully vaccinated individuals remains ill defined. Herein we report a confirmed transmission of SARS-CoV-2 alpha variant (B.1.1.7) from a symptomatic immunocompetent woman 4 weeks after her second dose of BNT162b2, despite antispike seroconversion.

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