From symptoms to vaccine efficacy, ABC News’ Dr. Jen Ashton breaks down some of the most asked omicron questions. abcashtonCoronavirusCOVID-19COVID19covid19 immunitydr.efficacyGMAimmune systemIMMUNITYJennewsomicronp_cmsid=2494279p_vid=news-81865582symptomsVaccineVITAMIN