Regarding the identification of chronic illnesses and prioritization the CDC outlines the following:
“Adults of any age with the following conditions are at increased risk of severe illness from the virus that causes COVID-19: Cancer; Chronic kidney disease; COPD (chronic obstructive pulmonary disease); Down Syndrome; Heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies; Immunocompromised state (weakened immune system) from solid organ transplant; Obesity (body mass index [BMI] of 30 kg/m2 or higher but < 40 kg/m2) Severe Obesity (BMI ≥ 40 kg/m2); Sickle cell disease; Smoking; Type 2 diabetes mellitus”
Asthma is identified as a condition that might put persons at an increased risk for severe illness from the virus that causes COVID-19. https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html#asthma
We are currently prioritizing those that are at increased risk, then move to those conditions where persons might be at increased risk.