COVID-19 Staff Testing of Antibody Responses Study (Co-Stars)

A total of 250 healthcare workers are currently off sick with symptoms of SARS-CoV-2
infection (COVID-19) while 99 additional members of staff have been diagnosed with confirmed
SARS-CoV-2 at Great Ormond Street Hospital. As a consequence, all routine surgery,
out-patient activity and day cases have been postponed or cancelled altogether. It is
therefore critical for us to understand whether or not this disease will continue to threaten
staff health or whether natural infection will give rise to long lasting immunity.

This is a 2-arm prospective cohort study recruiting at least 1000 healthcare workers at GOSH
over 6 years.Staff will be recruited and coordinated from each department to be
representative of the full diversity of healthcare workers at the Trust. The age distribution
of the participants will be monitored on a weekly, basis against the known age distribution
of the hospital to ensure that the sample is representative.

Trust communications team will send an all staff email to inform them about this research
project asking them to get in touch with the study team if they wish to participate and they
meet the basic eligibility criteria. Potential participants will be asked voluntarily to
attend a face to face appointment in person (or if preferred by telephone or 1:1 video
teleconference meeting) to enable trained study staff to seek informed consent before they
enter the study. Informed consent will be undertaken by study staff who are Good Clinical
Practice trained, Human Tissue Act trained, study trained, GOSH consent trained and
registered in the study log.

The consent process will specifically cover the reason for the study, the storage of samples
and agreement for future samples to be tested once improved testing is made available. Once
the member of staff has provided informed consent, they will be asked to undertake an online
questionnaire in which they will record demographic details including age, sex, email address
and telephone contact for results and coordinating follow up. The questionnaire will also
record details of SARS-CoV-2 like symptoms, contact with SARS-CoV-2, pre-existing
co-morbidities and medication or treatments that may interfere with serological testing.

After providing informed consent, the staff members then be asked attend the study phlebotomy
testing clinic. Appointments will be 20 minutes in length but actual blood sampling for
serological testing will be 5-10 minutes to allow plenty of time and space for staff members
to be tested to maintain social distancing. A total of 8ml of blood will be stored for
testing.

Follow up sampling and questionnaires of approximately 200 staff members with PCR confirmed
SARS-CoV-2 infected staff will take place monthly. While follow up of all ~800 asymptomatic
staff members will take place 6 monthly. All staff will continue to have access to the GOSH
PCR COVID19 testing program (as they do at present). This will enable us to confirm with PCR
testing any new (or reinfected) positive staff member with COVID-19 over the duration of the
study.

When initially asymptomatic seronegative staff become serologically positive during the
course of the study, they will remain under active surveillance but they will switch arms of
the study and they will contribute to the active follow up of serologically positive
patients.

If staff leave the GOSH NHS trust during the study they will still be eligible to remain in
the study and be followed up and we will update their contact details on the follow-up
questionnaire.

After the initial intensive phase, all approximately 1000 recruits will be followed 6 monthly
for the 6 year duration of the study. Follow-up visits will be arranged following the
baseline assessment. The same blood tests 4ml EDTA and 4ml serum will be taken at each follow
up appointment as well as the same symptom questionnaire.