COVID-19 Staff Testing of Antibody Responses Study (Co-Stars) (Co-Stars)
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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. |
ClinicalTrials.gov Identifier: NCT04380896 |
Recruitment Status :
Completed
First Posted : May 8, 2020
Last Update Posted : September 27, 2022
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Condition or disease | Intervention/treatment |
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SARS-CoV-2 Infection | Other: Blood test Other: Standardised questionnaires |

Study Type : | Observational |
Actual Enrollment : | 3502 participants |
Observational Model: | Cohort |
Time Perspective: | Prospective |
Official Title: | COVID-19 Staff Testing of Antibody Responses Study (CO-STARS) |
Actual Study Start Date : | April 27, 2020 |
Actual Primary Completion Date : | July 30, 2022 |
Actual Study Completion Date : | July 30, 2022 |

Group/Cohort | Intervention/treatment |
---|---|
SARS-CoV-2 Seropositive Cases
It will be formed of approximately N= 200 to 350 staff members Core Group of PCR Confirmed Cases N ~ 150 to 250: A) Symptoms consistent with SARS-CoV-2 infection and SARS-CoV-2 PCR Positive N ~ 150 to 250 OR Other SARS-CoV-2 Sero-positives N ~ 50 to 100: B) Symptoms consistent with SARS-CoV-2 infection and SARS-CoV-2 PCR Negative cases. OR C) No symptoms consistent with SARS-CoV-2 infection and PCR Not Tested cases |
Other: Blood test
Blood tests (8ml in total) 4ml blood for serological testing (measure the antibody titres to the SARS-CoV-2 nucleo-capsid protein (4ml) and 4ml EDTA to be stored for future research will be taken for each group. Other: Standardised questionnaires It will be an online questionnaire about staff members health, symptoms of SARS-CoV-2 and contact with SARS-CoV-2. All participants will also be asked to complete a detailed symptom and electronic questionnaire prior to each appointment. |
SARS-CoV-2 Seronegative Comparison Group
It will be formed of approximately N= 800 to 900 staff members Core Comparison Group N ~ 800 A) Have not had clinical symptoms consistent with SARS-CoV-2 infection OR Other Seronegatives N ~ 100 B) Have had sympoms of SARS-CoV-2 infection but have been tested and were PCR positive or negative but have not developed antibodies at 21 days |
Other: Blood test
Blood tests (8ml in total) 4ml blood for serological testing (measure the antibody titres to the SARS-CoV-2 nucleo-capsid protein (4ml) and 4ml EDTA to be stored for future research will be taken for each group. Other: Standardised questionnaires It will be an online questionnaire about staff members health, symptoms of SARS-CoV-2 and contact with SARS-CoV-2. All participants will also be asked to complete a detailed symptom and electronic questionnaire prior to each appointment. |
- Change in serial monthly log-transformed antibody titre levels as measured [ Time Frame: 6 months period post infection ]To determine the kinetics (rate of change) of SARS-CoV-2 nucleo-capsid protein antibody titres in proven cases of SARS-CoV-2 over the 6 month period following infection
- Proportion of completely asymptomatic healthcare workers with evidence of SARS-CoV-2 antibodies [ Time Frame: 12 months ]To determine the proportion of completely asymptomatic healthcare workers who have evidence of SARS-CoV-2 antibodies in their serum indicative of past infection
- The attack rate of SARS-CoV-2 in healthcare workers who have antibodies compared to those who do not [ Time Frame: Betwen 3 to 6 years ]To determine the attack rate of SARS-CoV-2 in healthcare workers who have antibodies versus those who do not have antibodies
- The immune correlates of protection against future exposure to SARS-CoV-2 [ Time Frame: Between 3 to 6 years ]To determine the immune correlates of protection (Antibody Titres sufficient for protection) against future exposure to SARS-CoV-2
Biospecimen Retention: Samples With DNA
Each sample will be tested using the EDITM diagnostic assay which detects the optical density of antibodies in serum samples to the nucleo-capsid protein SARS-CoV-2. Both IgM and IgG antibodies to the nucleo-capsid protein will be tested and reported.
At the end of the study the samples will be stored at -70oC in the freezers of the Great Ormond Street Camelia Botnar Laboratories for future research. Future studies may involve genetic testing on the samples and this has been highlighted on the consent form.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Sampling Method: | Probability Sample |
Inclusion Criteria for ARM 1: SARS-CoV-2 Seropositive Cases:
- Healthcare worker at GOSH
- >18 years of age
- ALL have confirmed detectable antibodies to SARS-CoV-2 infection on baseline screen
Then can be recruited into either of the following sub-groups
- Core Group of PCR Confirmed Cases : Must have symptoms consistent with SARS-CoV-2 infection and SARS-CoV-2 PCR Positive
- Other SARS-CoV-2 Sero-positives: May have Symptoms consistent with SARS-CoV-2 infection and SARS-CoV-2 PCR Negative cases OR May have no symptoms consistent with SARS-CoV-2 infection and PCR Not Tested cases
Inclusion Criteria for ARM 2: SARS-CoV-2 Seronegative Comparison Group :
- Healthcare worker at GOSH
- >18 years of age
- ALL have confirmed negative antibodies to SARS-CoV-2 infection on baseline screen
Then can be recruited into either of the following Sub-groups:
- Core Comparison Group: Have not had clinical symptoms consistent with SARS-CoV-2 infection*
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Other Seronegatives: Have had symptoms of SARS-CoV-2 infection but have been tested and were PCR positive or negative but have not developed antibodies at 21 days
- Clinical Symptoms for SARS-CoV-2 infection are defined as one of:
1) New and persistent cough 2) Confirmed temperatures of 37.8 and above 3) Anosmia
General Exclusion Criteria :
- <18 years of age
- On immunosuppressive or immunomodulatory medication that may impact test reliability
- Received any blood product including immunoglobulins after October 2019
- Has received convalescent sera as treatment
- Current diagnosis of a malignancy that may impact test reliability
- Those lacking capacity to provide informed consent

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04380896
United Kingdom | |
Great Ormond Street Hospital | |
London, United Kingdom, WC1N 3JH |
Principal Investigator: | Louis Grandjean, Dr | Great Ormond Street Hospital NHS Foundation Trust |
Responsible Party: | Great Ormond Street Hospital for Children NHS Foundation Trust |
ClinicalTrials.gov Identifier: | NCT04380896 |
Other Study ID Numbers: |
20CB17 |
First Posted: | May 8, 2020 Key Record Dates |
Last Update Posted: | September 27, 2022 |
Last Verified: | September 2022 |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
COVID-19 Pneumonia, Viral Pneumonia Respiratory Tract Infections Infections Virus Diseases |
Coronavirus Infections Coronaviridae Infections Nidovirales Infections RNA Virus Infections Lung Diseases Respiratory Tract Diseases |