Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT05274373 |
Other study ID # |
Covisera |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
|
First received |
|
Last updated |
|
Start date |
May 24, 2020 |
Est. completion date |
October 1, 2023 |
Study information
Verified date |
March 2022 |
Source |
Nordsjaellands Hospital |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational [Patient Registry]
|
Clinical Trial Summary
Assessment of the association between the severity of COVID-19 and SARS-CoV-2 NAb titers
levels for up to six months following primary infection using a live virus NAb assay.
Description of SARS-CoV-2 viral shedding and infectiousness during the first 30 days after
infection in a group of unvaccinated hospitalized patients.
Description:
The studys primary aim is to assess clinical factors, such as disease severity, associated
with neutralizing antibody (NAb) production. Furthermore, the study aims to assess the length
of SARS-CoV-2 infectiousness and clinical factors associated with viral load.
Patients 18 years or older hospitalized at Copenhagen University Hospital at North Zealand,
Copenhagen, Denmark, May 24th,2020 - May 5th, 2021, were routinely screened for COVID-19 by
diagnostic oropharyngeal or tracheal RT-PCR samples taken during admission. Patients with a
positive SARS-CoV-2 PCR within 48 hours from hospital admission were offered inclusion, if
COVID-19 pneumonia was confirmed.
The following were retrieved from patients' electronic records: comorbidities (Charlson
Comorbidity Index),vital signs (Early Warning Score), immunocompromised status, time from
symptom onset to admission, oxygen treatment, pharmacological treatment, admission length,
death and bacterial co-infection.
Paired oropharyngeal swabs and serum samples were collected at inclusion (day 0), days 3, 7,
10, 14, 17, 24, and 30. Serum samples were, if possible, also collected after three and six
months. Follow-up time was six months.
RT-qPCR analysis targeted the SARS-CoV-2 RNA-dependent-RNA-polymerase (RdRp)-helicase gene
region and two samples with known viral load were included in each PCR-run for quantification
of patient samples. Virus was cultured in African green monkey cells (VERO-E6) with
incubation for 3 - 4 days and daily microscopic inspection for cytopathogenic effect (CPE). A
total of three passages were made before the the virus was interpreted as non-replicant.
Cells with CPE were confirmed by RT-qPCR.
The presence of specific antibodies (Ab) against SARS-CoV-2 in serum was assessed using
Wantai total-Ab ELISA according to the manufacturer's instructions (Wantai, Beijing, China).
For the in-house live virus NAb analysis, a 50% cut-off value was calculated from
quadruplicate virus and cell control wells included on each plate using the following
equation: (average optical density (OD) of virus control wells + average OD of cell control
wells)/2. The 50% neutralization titer was calculated as the interpolation of the cutoff
value with a four-parameter logistic regression curve fitted for each serum serial dilution.
To minimize inter-assay variation, the titers were normalized according to a positive control
included on each assay plate.
A linear mxied-effects model was used to assess the association between repeated NAb
measurements and clinical variables such as age, gender and disease severity. A linear
mixed-effects model was also used to assess the association between repeated viral load
measurements and clinical variables.