This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Vaccination causing intussusception - 
Select and explain. 
A. Rotavirus, B. Parvovirus, C. Poliovirus, D. BCG
A: Rotavirus
Answer: A: Rotavirus 
Explanation: In 1999, a highly efficacious rotavirus vaccine, Rotashield licensed in the United States, was withdrawn from the market after less than one year because of its association with intussusception.