Walter A. Orenstein
Professor, Emory University School of Medicine
Expertise: Vaccines, Pediatrics
New York Times accurately reports vaccine-derived polio outbreaks caused by low vaccine coverage
in New York Times, by Associated Press
— 02 Dec 2019
"The content of the article is correct: attenuated polio strain type 2 contained in the oral vaccine can – in very rare cases – mutate and cause disease in under-immunized pers..