MURDOCK Cabarrus County COVID-19 Prevalence and Immunity (C3PI) Study

Method:

Questionnaire The investigators will use RedCap to introduce the study, obtain online informed consent, and administer an electronic questionnaire to MURDOCK Study participants currently residing in North Carolina who have a valid email address on file (N~7200). The question bank for the questionnaire is attached to the application. It includes demographics, education and employment, and questions about symptoms, contacts and exposures, the participant's household, behaviors, and practice of mitigation strategies. The opportunity to enroll and complete the baseline questionnaire will remain open for 1 month. Follow up surveys will be made available to consented participants on the same day for each week they are administered. The investigators anticipate a 20% response rate to the survey (N~1500). Recruitment materials, consent and questionnaires, materials related to return of results to participants, and verbal study communications will be available in both English and Spanish.

COVID-19 PCR testing A randomly selected subset of individuals who consent to participate (N~300-500 initially, with the potential to expand testing to more survey participants as additional funding becomes available), weighted to ensure representation by race/ethnicity, age, and sex, will be invited to participate in COVID-19 polymerase chain reaction (PCR) viral testing by at-home collection and return of self-administered nasal swabs. Saliva specimens may replace the nasal swab specimen. Specimens will be collected at baseline and every 2 weeks in conjunction with questionnaire administration. Participants will have the opportunity to opt out of participation in this component at the time of consent and enrollment. Those who do not opt out will be eligible for the random selection for COVID-19 testing. The investigators will provide specimen collection materials and instructions for collection, along with return shipping instructions to participants in pre-prepared kits. COVID-19 PCR testing will be conducted at the North Carolina State Laboratory of Public Health. This is a CLIA-certified laboratory. Samples for COVID-19 PCR testing will be identified only by a unique study identification number for each participant. Results of COVID-19 testing will be returned from the State Lab to the MURDOCK Study investigative team as results are available from testing (expected turnaround time ~4 days from receipt at State Lab) by secure transfer for incorporation into the RedCap study database.

COVID-19 serology testing The same randomly selected subset of individuals who collect at-home samples for COVID-19 PCR testing (N~300-500 initially, with the potential expand to more survey participants as additional resources become available), will also provide a blood sample for serologic testing for SARS-CoV-2 IgG antibodies. Specimens will be collected by routine venipuncture at the MURDOCK Study office in Kannapolis, NC and potentially 2-3 additional locations in Cabarrus County. Study visits for venipuncture will be deferred for 2 weeks in participants whose nasal swab PCR testing for COVID-19 is positive. Participants will be screened for COVID-19 symptoms at the time of scheduling the visit for venipuncture and at arrival for the visit. Participants who screen positive for COVID-19 symptoms will be referred for clinical COVID-19 testing and will have their initial serology testing deferred until a negative clinical test is documented or for 2 weeks if clinical testing is not performed.

Specimens for serology will be collected at baseline approximately 1 month after the first questionnaire and 2 weeks after the first nasal swab collection and COVID-19 PCR testing. Specimens for serology will be collected at least bi-monthly and up to monthly thereafter through a total study duration of 6, and up to 12, months. SARS-CoV-2 serologic testing for IgG antibodies will be conducted in the laboratory of Thomas Denny, MSc, MPhil in the Duke Human Vaccine Institute on the campus of Duke University Medical Center using a commercial IgG assay (Perkin-Elmer). Samples for serology will be identified only by a unique study identification number for each participant. Results of serological testing will be returned from the Denny laboratory to the MURDOCK Study investigative team at regular, prespecified intervals by secure transfer for incorporation into the RedCap study database. The Denny laboratory is CLIA-certified. Any residual serum after SARS-CoV-2 serologic testing will be frozen at -80°C and stored for future use in the Duke COVID-19 Biorepository (Pro00105316).