## Transmission Status

We estimate $$R_t$$ is currently around to for of Illinois. $$R_t$$, the instantaneous reproductive number, tells us whether the epidemic is growing ($$R_t$$ > 1), shrinking ($$R_t$$ < 1), or staying the same ($$R_t$$ = 1).

The curves below are estimated using different methods and data sources. Northwestern University (NU) estimates $$R_t$$ from a dynamical model, which is fitted to COVID-19 hospitalizations and deaths. The University of Chicago (UC) estimate derives from hospital admissions with COVID-like illness using methods in EpiNow2. Each curve is shown with its 95% CI. The date next to the model name refers to the date of model fit. For more details and links to the models, see the About page.

## Cases

This is the number of new infections discovered daily by diagnostic testing, as reported by the Illinois Department of Public Health. Individuals who receive multiple positive test results only count as one case. Bars show daily cases, and the line is a 7-day moving average. As of , an average of cases of SARS-CoV-2 infection are discovered daily in of Illinois.

This is the daily number of people admitted to the hospital for COVID-like illness (CLI) in of Illinois. CLI admissions are a gold-standard indicator for COVID-19 trends because unlike cases or test positivity rate, CLI admissions are much less sensitive to changes in diagnostic test availability or demand.

## Deaths

This is the number of daily COVID-19 confirmed deaths reported to the Illinois Department of Public Health. Reporting of deaths often lags behind reporting of cases, so death counts do not necessarily reflect date of death but are likely within two weeks. Bars show daily deaths, and the line is a 7-day moving average. As of , an average of confirmed COVID-19 deaths occur daily in of Illinois.

## Cases per Test (case positivity rate)

The case positivity rate is the number of cases discovered divided by the number of tests administered. This is not the same as the test positivity rate, which measures the number of positive tests per every test administered. Bars show the daily case positivity rate, and the line is a 7-day moving average. As of , an average of cases are discovered per test in of Illinois.

## Tests

This is the number of SARS-CoV-2 diagnostic tests administered daily in of Illinois. This count only includes diagnostic tests, which test for current SARS-CoV-2 infection. Serological tests, which test for past SARS-CoV-2 infection, are not included in this count. Diagnostic tests include only molecular tests up to October 14, 2020 and include both molecular and antigen tests after October 14, 2020. Bars show daily tests, and the line is a 7-day moving average. Dates are the date results were reported, not date of specimen collection. Spikes correspond to backlogged tests that were reported all at once. As of , an average of tests are conducted daily in of Illinois.

## Vaccination

This is the daily number of doses administered and newly fully vaccinated residents of of Illinois. As of , % of residents of of Illinois have been fully vaccinated. The cumulative number of doses distributed is and people have been fully vaccinated.