Coinspeaker Quidel (QDEL) Stock Soars Nearly 30% after Approval of Covid-19 Antigen TestQuidel (QDEL) stock goes up as the healthcare manufacturer has received approval from the US Food and Drug Administration (FDA) for its COVID-19 antigen test. It is quicker, cheaper and easier to develop than most other diagnostics.Quidel (QDEL) Stock Soars Nearly 30% after Approval of Covid-19 Antigen Test