LIINC is a study of volunteers who were previously infected with SARS-CoV-2 (also known as novel coronavirus or COVID-19) who have recovered from acute infection. The study is designed to provide a specimen bank of samples with carefully characterized clinical data. LIINC specimens will be used to examine multiple questions involving the virologic, immunologic, and host factors involved in COVID-19, with a focus on understanding variability in the long-term immune response between individuals.

LIINC is an observational, prospective study of individuals previously infected with SARS-CoV-2 who have recovered from acute illness. The overall objective of the study is to investigate the clinical consequences of SARS-CoV-2 infection. These include the pre-existence and development of medical conditions, measures of immune activation and inflammation, changes in immunologic function, and variability in host responses. There will be a specific focus on demographic differences including age, gender, and race.

Enrolled volunteers are seen at San Francisco General Hospital at baseline, monthly for 3 months and then every 3 months for up to 2 years. Visits include a detailed interview, saliva collection, and a blood draw. Baseline visits take approximately 90 minutes, and follow up visits take approximately 20-40 minutes. No personal identifiers are used for specimen bank samples.

Inclusion Criteria:

1. Willing and able to provide written informed consent, and

2. Age >/= 18 years, and

3. A history of SARS-CoV-2 infection, as evidenced by:

   1. Available laboratory documentation of SARS-CoV-2 RNA positivity on a nucleic acid amplification test or by serologic testing when this becomes available, or
   2. Reference by the participant to a laboratory test performed on respiratory tract secretions or blood, fingerstick, or saliva test that was reported to the participant to be positive for SARS-CoV-2 or COVID-19 infection,

4. And a period of 21 days or more has elapsed since the first positive test or symptoms preceding the first positive test, whichever is earlier.

Exclusion Criteria:

1. Self-reported or documented chronic anemia with hemoglobin < 9 g/dL. Anemia during a preceding acute illness will not be exclusionary.
2. Serious medical or psychiatric illness that, in the opinion of the site investigator, would interfere with the ability to adhere to study requirements or to give informed consent.
3. Active drug or alcohol use or dependence that, in the opinion of the Principal Investigator, would interfere with adherence to study requirements or to give informed consent.

The investigators will enroll individuals with prior SARS-CoV-2 infection across a wide spectrum of age, race, gender, and disease severity.