This study is a community hospital-based study that will enhance information being obtained in similar studies taking place in France, Denmark, and China. These studies are designed to assess risk of healthcare workers during outbreaks of Coronavirus 2019 (COVID-19) also known as sudden acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). This will be a prospective, single-center observational study involving human subjects. IgG (Immunoglobulin G) antibody will be tested in the serum of physicians working at Advocate Lutheran General Hospital (ALGH). IgG antibodies are the antibodies that form in response to viral or bacterial infections and typically reflect protection against said infection. To date, there have been no studies confirming that IgG antibody formation confers immunity, but studies are ongoing. Furthermore, data is lacking showing conclusive persistence of (possibly protective) antibodies over time. Attending physicians on the medical staff, fellow physicians, and house staff residents who worked at ALGH from March 1st, 2020 and on, will be eligible for the study. Testing will involve a venipuncture to obtain approximately 3mL of blood to be sent to ACL Laboratories for SARS-CoV-2 IgG testing. For physician subjects, this will be performed on four separate occasions, once at the onset of the study, a second test 3 months after the first test, a third test 6 months from the time of the first test, and a fourth and final test 12 months after the initial test. Two household members (defined below), one-time testing will occur within 2 weeks of the physician subject testing positive. All testing will be performed in a two-week window. All physician subjects will be tested at a centralized site that is only serving these subjects, by appointment. We will be offloading testing for household members to one localized commercial ACL site on the ALGH campus at the Center for Advanced Care. The household member testing will be extended to an additional two-week period after the two week window in which physicians are tested for a total of four weeks maximum. One-time testing for IgG antibodies to COVID-19 will be offered to a maximum of two household members, as defined as, any person over the age of 18 years old who has lived at home with the physician, who has tested positive for IgG antibodies, for at least 2 weeks in total duration since March 1st, 2020. The physician will be permitted to choose who gets tested, and the chosen adult subject will provide their independent consent to be tested.

Study is complete. Data analysis is being put together.

Inclusion Criteria:

• Attending physician staff members, fellow physicians, and resident house staff members who were on staff at ALGH from March 1st, 2020 and on, with potential exposure to COVID-19 patients.
• A maximum of two adult household members as defined as, any person over the age of 18 years old who has lived at home with the physician for at least 2 weeks in total duration since March 1st, 2020. Any adult household member of attending physicians on the medical staff, fellow physicians, and resident physicians may qualify as long as the tested physician resulted positive for IgG Antibodies to COVID-19. The adult household member will be selected by the household physician based on their assessment of risk of also testing positive.
• Must be willing to undergo venipuncture, sign consent and complete the questionnaire. Participants need to speak, read, and understand English at the literacy level of a 8th grader.
• Those with a prior documented COVID-19 infection are eligible for study inclusion. We will rely on self-reporting by physicians due to the fact that the data from the other study conducted in the Advocate Aurora System has been de-identified and we cannot access the results on individual participants in our study.

Exclusion Criteria:

• Healthcare providers and/or their household members who would not want venipuncture performed on them
• Healthcare workers who are not on the medical staff or members of the resident house staff

Advocate Lutheran General Hospital Physicians and their household members.