Oral live vaccine strain-induced protective immunity against pulmonary Francisella tularensis challenge is mediated by CD4+ T cells and antibodies, including immunoglobulin A.
Ray HJ, Cong Y, Murthy AK, Selby DM, Klose KE, Barker JR, Guentzel MN, Arulanandam BP. Oral live vaccine strain-induced protective immunity against pulmonary Francisella tularensis challenge is mediated by CD4+ T cells and antibodies, including immunoglobulin A. Clin Vaccine Immunol. 2009 Apr; 16(4):444-52.