Update on Immunodeficiency-Associated Vaccine-Derived Polioviruses - Worldwide, July 2018-December 2019. - Macklin, Grace; Diop, Ousmane M.; Humayun, Asghar; Shahmahmoodi, Shohreh; El-Sayed, Zeinab A.; Triki, Henda; Rey, Gloria; Avagyan, Tigran; Grabovac, Varja; Jorba, Jaume; Farag, Noha; Mach, Ondrej (MMWR: Morbidity & Mortality Weekly Report, 2020)