Agenus (AGEN) announced that The Food and Drug Administration (FDA) granted marketing authorization to GlaxoSmithKline's (GSK) product Shingrix, a herpes zoster vaccine containing Agenus' proprietary immune adjuvant QS-21 Stimulon®. Shingrix vaccine is designed to prevent herpes zoster (shingles) in adults aged 50 years and older. The adjuvant in the vaccine is Agenus’ product QS-21 Stimulon. This adjuvant is to help improve the vaccine's effectiveness by …