Introducing point and deletion mutations into the P/C gene of human parainfluenza virus type 1 (HPIV1) by reverse genetics generates attenuated and efficacious vaccine candidates - Bartlett,E.J.; Amaro-Carambot,E.; Surman,S.R.; Collins,P.L.; Murphy,B.R.; Skiadopoulos,M.H. (Vaccine, 2006)