Year-and-a-Half Old, Dried Echinacea Roots Retain Cytokine-Modulating Capabilities in an in vitro Human Older Adult Model of Influenza Vaccination - Senchina, David S; Wu, Lankun; Flinn, Gina N; Konopka, Del N; McCoy, Joe-Ann; Widrlechner, Mark P; Wurtele, Eve Syrkin; Kohut, Marian L (Planta Medica, 2006)