The National Network for Immunization Information (NNii) provides up-to-date, science-based information to healthcare professionals, the media, and the public: everyone who needs to know the facts about vaccines and immunization.

Vaccine Safety

Intussusception and Rotavirus Vaccine

The original rotavirus vaccine—Rotashield®—was shown to have caused intussusception at a rate of about 1 in 10,000 infants. What about the new vaccine?


For Professionals

This section includes links to general immunization recommendations in the United States and other valuable information for health professionals.