Mechanisms Underlying Asthma Exacerbations Prevented and Persistent With Immune-Based Therapy

Inclusion Criteria: Participant(s) who meet all of the following criteria are eligible for enrollment. Participant(s) may be reassessed if not initially eligible. Participants are eligible if they: * Have a primary place of residence in one of the pre-selected recruitment census tracts as outlined in the Inner City Asthma Consortium (ICAC) Manual of Procedures (MOP); * Have a diagnosis of asthma made by a clinician \>1 year prior to recruitment; * Have had at least 2 asthma exacerbations in the prior year, defined as a requirement for systemic corticosteroids and/or hospitalization; * Have the following requirement for asthma controller medication at the Screening and Enrollment Visit (Visit 0) according to the MEDS program\[4, 2\]: * For participants aged 6 to 11 years, treatment with at least fluticasone 250 mcg 1 puff twice daily or its equivalent; * For participants ages12 years and older, treatment with at least Advair 250/50 mcg 1 puff twice daily or its equivalent. * Have peripheral blood eosinophils \>=150 per mm\^3. Results can be obtained from participation in a previous ICAC study if obtained within 6 months of the Screening and Enrollment Visit (Visit 0); * Currently a non-smoker; * Parent/legal guardian is willing to sign the written informed consent; * Participant is willing to sign the assent form as per central Institutional Review Board (IRB) guidelines; * Has some form of insurance that covers costs of usual care asthma control and rescue medications at the Screening and Enrollment Visit (Visit 0). Exclusion Criteria: Participant(s) who meet any of the following criteria are not eligible for enrollment but may be reassessed. Participant(s) are ineligible if they: * Are currently pregnant or lactating; * Are currently receiving treatment with anti-immunoglobulin E (anti-IgE) therapy or have had anti-IgE therapy in the previous 3 months prior to screening; * Are currently receiving immunotherapy; * Have clinically significant abnormalities on complete blood count (CBC) with differential as determined by the site study clinician. Results can be obtained from participation in a previous ICAC study \[including Registry for Asthma Characterization and Recruitment 2 (RACR2), NCT02513264} if obtained within the last 6 months of Visit 0; * Was treated with systemic corticosteroids for any medical condition including an asthma exacerbation within the 2 weeks prior to Visit 0; * Have had a cold in the previous 7 days; * Are currently participating in an asthma-related pharmaceutical study or intervention study or has participated in another asthma-related pharmaceutical study or intervention study in the previous 4 weeks prior to recruitment; * Are currently requiring greater than fluticasone 500 mcg bid plus long-acting beta agonist (LABA) 1 puff twice daily or its equivalent and\\or individuals using oral corticosteroids daily or every other day at Visit 0. Participants who meet any of the following criteria are not eligible for enrollment and may not be reassessed. Participants are ineligible if they: * Have any medical illnesses that in the opinion of the investigators would a.) increase the risk the participant would incur by participating in the study, b.) interfere with the measured outcomes of the study, or c.) interfere with the performance of the study procedures. Examples of such diseases are: phenylketonuria, cystic fibrosis, bronchiectasis, Type 1 diabetes, hemophilia, Von Willebrands disease, sickle cell disease, cerebral palsy, rheumatoid arthritis, lupus, psoriasis, hyperimmunoglobulin E syndrome, parasite infections, Wiskott-Aldrich syndrome, or allergic bronchopulmonary aspergillosis. * Have concurrent medical problems that would require systemic corticosteroids (other than for treatment of an asthma exacerbation) or other immunomodulators during the study; * Currently have diagnosed cancer, are currently being investigated for possible cancer, or have a history of cancer; * Have plans to move from the area during the study period; * Do not primarily speak English (or Spanish at clinical sites with Spanish speaking staff); * Have a primary caretaker who does not speak English (or Spanish at clinical sites with Spanish-speaking staff; not applicable if participant is able to provide consent); * Are a foster child; * Will not allow the study clinician to manage their disease for the duration of the study or are not willing to change their asthma medications to follow the protocol; * Are not able to perform pulmonary function tests; * Have known hypersensitivity to any of the medications that will be used for the treatment of asthma; * Have had a life-threatening asthma exacerbation in the last 2 years requiring intubation, mechanical ventilation, or resulting in a hypoxic seizure.