fix covid exploration

[dsweber2]

currently it isn't testing the correct data

[dshemetov]

In our NHSN data processing, we have

      hhs = previous_day_admission_adult_covid_confirmed +
        previous_day_admission_adult_covid_suspected +
        previous_day_admission_pediatric_covid_confirmed +
        previous_day_admission_pediatric_covid_suspected

which should have been only the confirmed columns.

[dshemetov]

This is fixed on main now.