In this study, the Kaiser Permanente Colorado (KPCO) Institute for Health Research (IHR) will evaluate SARS-CoV-2 IgG antibody titers over time among individuals with evidence of prior infection, and correlate antibody titers with risk of recurrent infection. The investigators will identify KPCO members who have and have not had prior infection, enroll them into a cohort study, conduct serial surveys for new COVID-19 symptoms, and facilitate serial viral and antibody testing.~All laboratory testing procedures and clinical management of participants will be conducted by KPCO operations. The research team will identify participants, obtain consent, administer surveys to assess COVID-19 symptoms, and direct patients to the appropriate testing. Health outcomes on cohort participants will be tracked with survey data on symptoms, clinical and utilization data from the KPCO electronic health record (e.g., hospitalization), and laboratory data (e.g., viral test results).~This research-operations partnership strategy will generate data to better understand the implications of positive antibody titers to this novel pathogen.
The goal of this study is to identify Kaiser Permanente Colorado (KPCO) members who have had COVID-19 infection for serial antibody testing and PCR testing to:~Quantify antibody titers among previously infected COVID-19 participants over 9 months.~Determine the rates of asymptomatic, mild, and severe recurrent infection among COVID-19 participants.~Examine association between antibody titer levels and risk of recurrent infection.~We will also identify KPCO members from the overall membership did not have any evidence of COVID-19 infection as a comparison group. In these participants we will also conduct serial antibody and viral testing and measure infection rates. This will allow us to compare whether participants with and without antibodies have different rates of infection.