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2.
Vaccines ; 10(4):585, 2022.
Article in English | MDPI | ID: covidwho-1786096

ABSTRACT

The long-term effect of protection by two doses of SARS-CoV-2 vaccination in patients receiving chronic intermittent hemodialysis (CIHD) is an urging question. We investigated the humoral and cellular immune response of 42 CIHD patients who had received two doses of SARS-CoV-2 vaccine, and again after a booster vaccine with mRNA-1273 six months later. We measured antibody levels and SARS-CoV-2-specific surrogate neutralizing antibodies (SNA). Functional T cell immune response to vaccination was assessed by quantifying interferon-γ(IFN-γ) and IL-2 secreting T cells specific for SARS-CoV-2 using an ELISpot assay. Our data reveal a moderate immune response after the second dose of vaccination, with significantly decreasing SARS-CoV-2-specific antibody levels and less than half of the study group showed neutralizing antibodies six months afterwards. Booster vaccines increased the humoral response dramatically and led to a response rate of 89.2% for antibody levels and a response rate of 94.6% for SNA. Measurement in a no response/low response (NR/LR) subgroup of our cohort, which differed from the whole group in age and rate of immunosuppressive drugs, indicated failure of a corresponding T cell response after the booster vaccine. We strongly argue in favor of a regular testing of surrogate neutralizing antibodies and consecutive booster vaccinations for CIHD patients to provide a stronger and persistent immunity.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-331436

ABSTRACT

The recent surge of infections with SARS-CoV-2 Omicron subvariants of prompted countries, such as Israel and Germany, to call for an accelerated booster vaccination program for health care workers and vulnerable groups in order to limit disease and transmission. However, detailed studies analyzing the correlates of protection over time after second booster vaccination are still lacking. Here, we examined the production of Spike receptor binding domain (RBD) -specific antibodies as well as neutralizing antibodies from subjects before, two, and seven weeks after the second booster vaccination against the D614G harboring B.1 variant as well as the variants of concern (VOC) Alpha, Beta, Delta in addition to Omicron BA.1 and BA.2. The second booster vaccination resulted in an increase in anti-RBD IgG antibodies and neutralizing antibodies against B.1 in all individuals tested, then remained nearly constant over the observed period. In addition, a 2nd booster resulted in an increase in neutralizing antibodies against VOCs Alpha, Beta, Delta, and Omicron subvariants BA.1 and BA.2. However, compared to B.1 the neutralizing capacity of both Omicron subvariants remained low. Neutralization of Omicron BA.1 and BA.2 was limited even after the 2nd booster vaccination indicating that an antibody-mediated protection against infection with this VOC is unlikely, as evidenced by the fact that three of the quadruple vaccinated individuals became infected with BA.1 during the course of the study. Moreover, T cell activation measured by interferon gamma release was detected in all subjects after the 2nd booster vaccination. This may offer protection suggesting protection against severe disease. T-cell activation was independent of the age of the subjects, but correlated with the amount of Spike-specific antibodies. Interestingly, in subjects with Omicron BA.1 breakthrough infection, a significant increase in neutralizing antibodies to all tested VOCs studied was observed after the 2nd booster vaccination. Taken together, our data suggest inferior protection from breakthrough infection with the Omicron subvariant BA.1 when compared to other VOCs after four vaccine doses.

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-316975

ABSTRACT

Multiple myeloma patients are often treated with immunomodulatory drugs, proteasome inhibitors or monoclonal antibodies until disease progression. Chronic therapy in combination with the underlying disease frequently results in severe humoral and cellular immunodeficiency, which often manifests in recurrent infections. Here we report on the clinical management and immunological data of one multiple myeloma patient diagnosed with COVID-19. Despite severe hypogammaglobulinemia, deteriorated T cell counts and neutropenia, the patient unexpectedly combated COVID-19 by balanced response of innate immunity, strong CD8+ and CD4+ T cell activation and differentiation, development of specific T-cell memory subsets, as well as development of anti-SARS-CoV-2 type IgA and IgG antibodies. Even 6 months after re-introduction of lenalidomide maintenance therapy, specific T cell response and antibody levels remained detectable, indicating persisting immunity against SARS-CoV-2. We conclude that in MM patients who tested positive for SARS-CoV-2 and were receiving active MM treatment, immune response assessment could be a useful tool to help guide decision-making regarding the continuation of anti-tumor therapy and supportive therapy.

5.
Nephrol Dial Transplant ; 2022 Jan 31.
Article in English | MEDLINE | ID: covidwho-1662129

ABSTRACT

INTRODUCTION: The vital renal replacement therapy makes it impossible for dialysis patients to distance themselves socially. This results in a high risk of SARS-CoV-2 infection and developing COVID-19 with excess mortality due to disease burden and immunosuppression. We determined the efficacy of a 100 µg booster of mRNA-1273 (Moderna, Inc., Cambridge, Massachusetts, USA) 6 months after two doses of BNT162b2 (BioNTech/Pfizer, Mainz, Germany/New York, NY, USA) in 194 SARS-CoV-2 naïve dialysis patients. METHODS: Anti-SARS-CoV-2-spike antibodies were measured with the Elecsys® Anti-SARS-CoV-2 S assay (Roche Diagnostics GmbH, Germany) 4 and 10-12 weeks after two doses of BNT162b2 as well as 4 weeks after the mRNA-1273 booster. The presence of neutralizing antibodies was measured by the SARS-CoV-2 Surrogate Virus Neutralization Test (GenScript Biotech, USA). Two different cut-offs for positivity were used, one according to the manufacturer's specifications and one correlating with positivity in a plaque reduction neutralization test (PRNT). ROC analyses were performed to match the anti-SARS-CoV-2-spike antibody cut-offs with the cut-offs in the surrogate neutralization assay accordingly. RESULTS: Any level of immunoreactivity determined by anti-SARS-CoV-2-spike antibody assay was found in 87.3% (n = 144/165) and 90.6% (n = 164/181) 4 and 10-12 weeks after two doses of BNT162b2. This was reduced to 68.5% or 60.6% 4 weeks and 51.7% or 35.4% 10-12 weeks, respectively, when using the ROC revealed cut-offs for neutralizing antibodies in the surrogate neutralization test (manufacturer given cut-off ≥ 103 U/ml and cut-off correlating with PRNT ≥ 196 U/ml). Four weeks after the mRNA-1273 booster, the concentration of anti-SARS-CoV-2-spike antibodies increased to 23 119.9 U/ml and consecutively to 97.3% for both cut-offs of neutralizing antibodies. CONCLUSION: Two doses of BNT162b2 followed by one dose of mRNA-1273 within 6 months in patients receiving maintenance dialysis resulted in significant titers of SARS-CoV-2-S-Ab. While two doses of mRNA vaccine only achieved adequate humoral immunity in a minority, the third vaccination boosts the development of virus-neutralizing quantities of SARS-CoV-2 spike antibodies (against wild type SARS-CoV-2) in almost all patients.

6.
PLoS One ; 17(1): e0262656, 2022.
Article in English | MEDLINE | ID: covidwho-1638777

ABSTRACT

SARS-CoV-2, the cause of COVID-19, requires reliable diagnostic methods to track the circulation of this virus. Following the development of RT-qPCR methods to meet this diagnostic need in January 2020, it became clear from interlaboratory studies that the reported Ct values obtained for the different laboratories showed high variability. Despite this the Ct values were explored as a quantitative cut off to aid clinical decisions based on viral load. Consequently, there was a need to introduce standards to support estimation of SARS-CoV-2 viral load in diagnostic specimens. In a collaborative study, INSTAND established two reference materials (RMs) containing heat-inactivated SARS-CoV-2 with SARS-CoV-2 RNA loads of ~107 copies/mL (RM 1) and ~106 copies/mL (RM 2), respectively. Quantification was performed by RT-qPCR using synthetic SARS-CoV-2 RNA standards and digital PCR. Between November 2020 and February 2021, German laboratories were invited to use the two RMs to anchor their Ct values measured in routine diagnostic specimens, with the Ct values of the two RMs. A total of 305 laboratories in Germany were supplied with RM 1 and RM 2. The laboratories were requested to report their measured Ct values together with details on the PCR method they used to INSTAND. This resultant 1,109 data sets were differentiated by test system and targeted gene region. Our findings demonstrate that an indispensable prerequisite for linking Ct values to SARS-CoV-2 viral loads is that they are treated as being unique to an individual laboratory. For this reason, clinical guidance based on viral loads should not cite Ct values. The RMs described were a suitable tool to determine the specific laboratory Ct for a given viral load. Furthermore, as Ct values can also vary between runs when using the same instrument, such RMs could be used as run controls to ensure reproducibility of the quantitative measurements.


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , Diagnostic Tests, Routine/methods , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , Viral Load/methods , COVID-19/epidemiology , COVID-19/virology , Genes, Viral , Germany/epidemiology , Humans , Reproducibility of Results
7.
Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz ; 65(1): 86-95, 2022 Jan.
Article in German | MEDLINE | ID: covidwho-1568341

ABSTRACT

Disinfection measures have become more important as a result of the COVID-19 pandemic in Germany. The increased need for disinfectants at the beginning of the pandemic required temporary legal regulations in order to provide a sufficient quantity of products for the necessary disinfection in the medical sector on the one hand and for the additional demand in the population on the other. For this purpose, the Federal Institute for Drugs and Medical Devices (BfArM) and the Federal Institute for Occupational Safety and Health (BAuA) issued a general ruling, which is explained in more detail in this article. The focus was on measures for hygienic hand disinfection. However, other applications such as surface disinfection in relation to pandemic respiratory diseases are also addressed. The experience gained in ensuring the supply of disinfectants that are effective and safe to use should be used to prepare for further pandemics.


Subject(s)
COVID-19 , Disinfectants , Disinfection , Germany , Humans , Pandemics/prevention & control , SARS-CoV-2
8.
Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz ; : 1-10, 2021.
Article in German | EuropePMC | ID: covidwho-1564081

ABSTRACT

Durch die COVID-19-Pandemie haben Desinfektionsmaßnahmen auch in Deutschland an Bedeutung gewonnen. Der erhöhte Bedarf an Desinfektionsmitteln zu Beginn der Pandemie erforderte es, vorübergehende rechtliche Regelungen zu treffen, um einerseits ausreichend Mittel für die notwendige Desinfektion im medizinischen Bereich und andererseits für den zusätzlichen Bedarf in der Bevölkerung zur Verfügung zu haben. Dazu wurden vom Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM) und der Bundesanstalt für Arbeitsschutz und Arbeitsmedizin (BAuA) Allgemeinverfügungen erlassen, die in diesem Beitrag näher erläutert werden. Im Vordergrund stehen dabei die Maßnahmen für die hygienische Händedesinfektion. Aber auch weitere Anwendungen wie die Flächendesinfektion im Zusammenhang mit pandemischen Atemwegserkrankungen werden erörtert. Die Erfahrungen bei der Sicherstellung der Versorgung mit wirksamen und in der Anwendung sicheren Desinfektionsmitteln sollten für die Vorbereitung weiterer Pandemien genutzt werden.

9.
Clin Infect Dis ; 73(9): e3036-e3041, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1501049

ABSTRACT

BACKGROUND: With the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ongoing in Europe in June 2020, day care centers were reopened in the state of Hesse, Germany, after the lockdown. The role young children play in the dynamics of the transmission was unknown. METHODS: We conducted a longitudinal study over 12 weeks and 2 days (18 June 2020-10 September 2020) to screen attendees and staff from day care centers in the state of Hesse, Germany, for both respiratory and gastrointestinal shedding of SARS-CoV-2. A total of 859 children (age range, 3 months-8 years) and 376 staff members from 50 day care centers, which were chosen representatively from throughout the state, participated in the study. Parents were asked to collect both a buccal mucosa and an anal swab from their children once a week. Staff were asked to self-administer the swabs. Reverse transcriptas polymerase chain reaction for SARS-CoV-2 was performed in a multiple-swab pooling protocol. RESULTS: A total of 7366 buccal mucosa swabs and 5907 anal swabs were analyzed. No respiratory or gastrointestinal shedding of SARS-CoV-2 was detected in any of the children. Shedding of SARS-CoV-2 was detected in 2 staff members from distinct day care centers. One was asymptomatic at the time of testing, and one was symptomatic and did not attend the facility on that day. CONCLUSION: Detection of either respiratory or gastrointestinal shedding of SARS-CoV-2 RNA in children and staff members attending day care centers was rare in the context of limited community activity and with infection prevention measures in the facilities in place.


Subject(s)
COVID-19 , SARS-CoV-2 , Child , Child, Preschool , Communicable Disease Control , Day Care, Medical , Germany/epidemiology , Humans , Infant , Longitudinal Studies , RNA, Viral
10.
J Mol Med (Berl) ; 100(3): 463-470, 2022 03.
Article in English | MEDLINE | ID: covidwho-1473984

ABSTRACT

Multiple myeloma patients are often treated with immunomodulatory drugs, proteasome inhibitors, or monoclonal antibodies until disease progression. Continuous therapy in combination with the underlying disease frequently results in severe humoral and cellular immunodeficiency, which often manifests in recurrent infections. Here, we report on the clinical management and immunological data of three multiple-myeloma patients diagnosed with COVID-19. Despite severe hypogammaglobulinemia, deteriorated T cell counts, and neutropenia, the patients were able to combat COVID-19 by balanced response of innate immunity, strong CD8+ and CD4+ T cell activation and differentiation, development of specific T-cell memory subsets, and development of anti-SARS-CoV-2 type IgM and IgG antibodies with virus-neutralizing capacities. Even 12 months after re-introduction of lenalidomide maintenance therapy, antibody levels and virus-neutralizing antibody titers remained detectable, indicating persisting immunity against SARS-CoV-2. We conclude that in MM patients who tested positive for SARS-CoV-2 and were receiving active MM treatment, immune response assessment could be a useful tool to help guide decision-making regarding the continuation of anti-tumor therapy and supportive therapy. KEY MESSAGES: Immunosuppression due to multiple myeloma might not be the crucial factor that is affecting the course of COVID-19. In this case, despite pre-existing severe deficits in CD4+ T-cell counts and IgA und IgM deficiency, we noticed a robust humoral and cellular immune response against SARS-CoV-2. Evaluation of immune response and antibody titers in MM patients that were tested positive for SARS-CoV-2 and are on active MM treatment should be performed on a larger scale; the findings might affect further treatment recommendations for COVID-19, MM treatment re-introduction, and isolation measures.


Subject(s)
COVID-19/immunology , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Multiple Myeloma/immunology , Multiple Myeloma/virology , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , Humans , Immunoglobulin G/immunology , Male , Middle Aged
11.
J Infect Dis ; 224(7): 1109-1114, 2021 10 13.
Article in English | MEDLINE | ID: covidwho-1470152

ABSTRACT

Whether monoclonal antibodies are able to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern has been investigated using pseudoviruses. In this study we show that bamlanivimab, casirivimab, and imdevimab efficiently neutralize authentic SARS-CoV-2, including variant B.1.1.7 (alpha), but variants B.1.351 (beta) and P.2 (zeta) were resistant against bamlanivimab and partially resistant to casirivimab. Whether antibodies are able to neutralize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variantshas been investigated using pseudoviruses. We show that authentic SARS-CoV-2 carrying E484K were resistant against bamlanivimab and less susceptible to casirivimab, convalescent and vaccine-elicited sera.


Subject(s)
COVID-19/virology , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Amino Acid Substitution , Antibodies, Monoclonal, Humanized/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Humans , Mutation, Missense , Neutralization Tests
12.
Pediatr Neonatol ; 62(1): 11-20, 2021 01.
Article in English | MEDLINE | ID: covidwho-1386441

ABSTRACT

Characterization of neonates born to mothers with SARS-CoV-2 infection has been partially carried out. There has been no systematic review providing a holistic neonatal presentation including possible vertical transmission. A systematic literature search was performed using PubMed, Google Scholar and Web of Science up to June, 6 2020. Studies on neonates born to mothers with SARS-CoV-2 infection were included. A binary random effect model was used for prevalence and 95% confidence interval. 32 studies involving 261 neonates were included in meta-analysis. Most neonates born to infected mothers did not show any clinical abnormalities (80.4%). Clinical features were dyspnea in 11 (42.3%) and fever in 9 newborns (19.1%). Of 261 neonates, 120 neonates were tested for infection, of whom 12 (10.0%) tested positive. Swabs from placenta, cord blood and vaginal secretion were negative. Neonates are mostly non affected by the mother's SARS-CoV-2 infection. The risk of vertical transmission is low.


Subject(s)
COVID-19/transmission , Infectious Disease Transmission, Vertical , Pregnancy Complications, Infectious , SARS-CoV-2 , Female , Humans , Infant, Newborn , Male , Pregnancy
13.
Transfusion ; 60(6): 1119-1122, 2020 06.
Article in English | MEDLINE | ID: covidwho-1388414

ABSTRACT

Oral swabs, sputum, and blood samples from 18 asymptomatic and symptomatic patients with SARS-CoV-2 infection were examined using RT-PCR testing in order to assess the risk of transfusion-related transmission. In asymptomatic patients as well as patients with flu-like symptoms and fever, no SARS-CoV-2 RNA could be detected in the blood or serum despite a clearly positive result in all throat swabs. As patients with symptoms of infectious disease will not be admitted to blood donation, the risk for transfusion transmission of SARS-CoV-2 seems to be negligible.


Subject(s)
Asymptomatic Infections , Betacoronavirus/isolation & purification , Blood Donors , Blood Safety , Coronavirus Infections/transmission , Donor Selection , Pneumonia, Viral/transmission , Transfusion Reaction/prevention & control , Adolescent , Adult , Aged , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/diagnosis , Female , Germany , Humans , Male , Middle Aged , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/diagnosis , SARS-CoV-2 , Transfusion Reaction/virology , Young Adult
15.
Med Microbiol Immunol ; 210(4): 235-244, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1292088

ABSTRACT

The novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Laboratory work with SARS-CoV-2 in a laboratory setting was rated to biosafety level 3 (BSL-3) biocontainment level. However, certain research applications in particular in molecular biology require incomplete denaturation of the proteins, which might cause safety issues handling contaminated samples. In this study, we evaluated lysis buffers that are commonly used in molecular biological laboratories for their ability to inactivate SARS-CoV-2. In addition, viral stability in cell culture media at 4 °C and on display glass and plastic surfaces used in laboratory environment was analyzed. Furthermore, we evaluated chemical and non-chemical inactivation methods including heat inactivation, UV-C light, addition of ethanol, acetone-methanol, and PFA, which might be used as a subsequent inactivation step in the case of insufficient inactivation. We infected susceptible Caco-2 and Vero cells with pre-treated SARS-CoV-2 and determined the tissue culture infection dose 50 (TCID50) using crystal violet staining and microscopy. In addition, lysates of infected cells and virus containing supernatant were subjected to RT-qPCR analysis. We have found that guanidine thiocyanate and most of the tested detergent containing lysis buffers were effective in inactivation of SARS-CoV-2, however, the M-PER lysis buffer containing a proprietary detergent failed to inactivate the virus. In conclusion, careful evaluation of the used inactivation methods is required especially for non-denaturing buffers. Additional inactivation steps might be necessary before removal of lysed viral samples from BSL-3.


Subject(s)
Anti-Infective Agents/pharmacology , COVID-19/prevention & control , COVID-19/virology , Guanidines/pharmacology , SARS-CoV-2/drug effects , Thiocyanates/pharmacology , Virus Inactivation , Animals , Caco-2 Cells , Cell Line , Chlorocebus aethiops , Containment of Biohazards , Humans , RNA, Viral , Real-Time Polymerase Chain Reaction , SARS-CoV-2/physiology , Specimen Handling/methods , Time Factors , Vero Cells
16.
J Clin Med ; 10(10)2021 May 14.
Article in English | MEDLINE | ID: covidwho-1234752

ABSTRACT

The plaque reduction neutralization test (PRNT) is a preferred method for the detection of functional, SARS-CoV-2 specific neutralizing antibodies from serum samples. Alternatively, surrogate enzyme-linked immunosorbent assays (ELISAs) using ACE2 as the target structure for the detection of neutralization-competent antibodies have been developed. They are capable of high throughput, have a short turnaround time, and can be performed under standard laboratory safety conditions. However, there are very limited data on their clinical performance and how they compare to the PRNT. We evaluated three surrogate immunoassays (GenScript SARS-CoV-2 Surrogate Virus Neutralization Test Kit (GenScript Biotech, Piscataway Township, NJ, USA), the TECO® SARS-CoV-2 Neutralization Antibody Assay (TECOmedical AG, Sissach, Switzerland), and the Leinco COVID-19 ImmunoRank™ Neutralization MICRO-ELISA (Leinco Technologies, Fenton, MO, USA)) and one automated quantitative SARS-CoV-2 Spike protein-based IgG antibody assay (Abbott GmbH, Wiesbaden, Germany) by testing 78 clinical samples, including several follow-up samples of six BNT162b2 (BioNTech/Pfizer, Mainz, Germany/New York, NY, USA) vaccinated individuals. Using the PRNT as a reference method, the overall sensitivity of the examined assays ranged from 93.8 to 100% and specificity ranged from 73.9 to 91.3%. Weighted kappa demonstrated a substantial to almost perfect agreement. The findings of our study allow these assays to be considered when a PRNT is not available. However, the latter still should be the preferred choice. For optimal clinical performance, the cut-off value of the TECO assay should be individually adapted.

17.
Eur Arch Otorhinolaryngol ; 278(9): 3551-3558, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1118224

ABSTRACT

PURPOSE: Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) replicates predominantly in the upper respiratory tract and is primarily transmitted by droplets and aerosols. Taking the medical history for typical COVID-19 symptoms and PCR-based SARS-CoV-2 testing have become established as screening procedures. The aim of this work was to describe the clinical appearance of SARS-CoV-2-PCR positive patients and to determine the SARS-CoV-2 contact risk for health care workers (HCW). METHODS: The retrospective study included n = 2283 SARS-CoV-2 PCR tests from n = 1725 patients with otorhinolaryngological (ORL) diseases performed from March to November 2020 prior to inpatient treatment. In addition, demographic data and medical history were assessed. RESULTS: n = 13 PCR tests (0.6%) were positive for SARS-CoV-2 RNA. The positive rate showed a significant increase during the observation period (p < 0.01). None of the patients had clinical symptoms that led to a suspected diagnosis of COVID-19 before PCR testing. The patients were either asymptomatic (n = 4) or had symptoms that were interpreted as symptoms typical of the ORL disease or secondary diagnoses (n = 9). CONCLUSION: The identification of SARS-CoV-2-positive patients is a considerable challenge in clinical practice. Our findings illustrate that taking a medical history alone is of limited value and cannot replace molecular SARS-CoV-2 testing, especially for patients with ORL diseases. Our data also demonstrate that there is a high probability of contact with SARS-CoV-2-positive patients in everyday clinical practice, so that the use of personal protective equipment, even in apparently "routine cases", is highly recommended.


Subject(s)
COVID-19 , Otorhinolaryngologic Diseases , COVID-19 Testing , Humans , RNA, Viral , Retrospective Studies , SARS-CoV-2
18.
J Virol Methods ; 291: 114102, 2021 05.
Article in English | MEDLINE | ID: covidwho-1085514

ABSTRACT

Multiple nucleic acid amplification tests (NATs) are available for the detection of SARS-CoV-2 in clinical specimens, including Laboratory Developed Tests (LDT), commercial high-throughput assays and point-of-care tests. Some assays were just recently released and there is limited data on their clinical performance. We compared the Xpert® Xpress SARS-CoV-2 (Cepheid) and Vivalytic VRI Panel (Schnelltest COVID-19) (Bosch) point-of-care tests with four high-throughput assays and one LDT, the cobas® SARS-CoV-2 test (Roche), the Allplex™ 2019-nCoV Assay (Seegene), the SARS-CoV-2 AMP (Abbott) Kit, the RealStar® SARS-CoV-2 RT-PCR Kit 1.0 (altona) as well as an assay using a SARS-CoV-2 RdRP gene specific primer and probe set. Samples from patients with confirmed SARS-CoV-2 infection, samples from the first and second SARS-CoV-2-PCR External Quality Assessment (EQA) (INSTAND e.V.) and a 10-fold serial dilution of a SARS-CoV-2 cell culture (SARS-CoV-2 Frankfurt 1) supernatant were examined. We determined that the NAT assays examined had a high specificity. Assays using the N gene as target demonstrated the highest sensitivity in the serial dilution panel, while all examined NAT assays showed a comparable sensitivity when testing clinical and EQA samples.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , High-Throughput Screening Assays/methods , Point-of-Care Testing , SARS-CoV-2/isolation & purification , COVID-19 Nucleic Acid Testing/methods , Clinical Laboratory Techniques/methods , Humans , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics , Sensitivity and Specificity
19.
J Clin Med ; 10(2)2021 Jan 17.
Article in English | MEDLINE | ID: covidwho-1076627

ABSTRACT

Due to globally rising numbers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, resources for real-time reverse-transcription polymerase chain reaction (rRT-PCR)-based testing have been exhausted. In order to meet the demands of testing and reduce transmission, SARS-CoV-2 antigen-detecting rapid diagnostic tests (Ag-RDTs) are being considered. These tests are fast, inexpensive, and simple to use, but whether they detect potentially infectious cases has not been well studied. We evaluated three lateral flow assays (RIDA®QUICK SARS-CoV-2 Antigen (R-Biopharm), SARS-CoV-2 Rapid Antigen Test (Roche)), and NADAL® COVID-19 Ag Test (Nal von Minden GmbH, Regensburg, Germany) and one microfluidic immunofluorescence assay (SARS-CoV-2 Ag Test (LumiraDx GmbH, Cologne, Germany)) using 100 clinical samples. Diagnostic rRT-PCR and cell culture testing as a marker for infectivity were performed in parallel. The overall Ag-RDT sensitivity for rRT-PCR-positive samples ranged from 24.3% to 50%. However, for samples with a viral load of more than 6 log10 RNA copies/mL (22/100), typically seen in infectious individuals, Ag-RDT positivity was between 81.8% and 100%. Only 51.6% (33/64) of the rRT-PCR-positive samples were infectious in cell culture. In contrast, three Ag-RDTs demonstrated a more significant correlation with cell culture infectivity (61.8-82.4%). Our findings suggest that large-scale SARS-CoV-2 Ag-RDT-based testing can be considered for detecting potentially infective individuals and reducing the virus spread.

20.
J Clin Med ; 10(2)2021 Jan 17.
Article in English | MEDLINE | ID: covidwho-1031144

ABSTRACT

Due to globally rising numbers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, resources for real-time reverse-transcription polymerase chain reaction (rRT-PCR)-based testing have been exhausted. In order to meet the demands of testing and reduce transmission, SARS-CoV-2 antigen-detecting rapid diagnostic tests (Ag-RDTs) are being considered. These tests are fast, inexpensive, and simple to use, but whether they detect potentially infectious cases has not been well studied. We evaluated three lateral flow assays (RIDA®QUICK SARS-CoV-2 Antigen (R-Biopharm), SARS-CoV-2 Rapid Antigen Test (Roche)), and NADAL® COVID-19 Ag Test (Nal von Minden GmbH, Regensburg, Germany) and one microfluidic immunofluorescence assay (SARS-CoV-2 Ag Test (LumiraDx GmbH, Cologne, Germany)) using 100 clinical samples. Diagnostic rRT-PCR and cell culture testing as a marker for infectivity were performed in parallel. The overall Ag-RDT sensitivity for rRT-PCR-positive samples ranged from 24.3% to 50%. However, for samples with a viral load of more than 6 log10 RNA copies/mL (22/100), typically seen in infectious individuals, Ag-RDT positivity was between 81.8% and 100%. Only 51.6% (33/64) of the rRT-PCR-positive samples were infectious in cell culture. In contrast, three Ag-RDTs demonstrated a more significant correlation with cell culture infectivity (61.8-82.4%). Our findings suggest that large-scale SARS-CoV-2 Ag-RDT-based testing can be considered for detecting potentially infective individuals and reducing the virus spread.

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