Rotavirus redux: FDA approves childhood vaccine for viral pathogen

February 10, 2006

The US Food and Drug Administration earlier this month approved Merck's vaccine to prevent rotavirus gastroenteritis, a leading cause of severe diarrhea in infants and young children. RotaTeq, an oral, three-dose vaccine, is given to infants 6 to 32 weeks old.

The US Food and Drug Administration earlier this month approved Merck's vaccine to prevent rotavirus gastroenteritis, a leading cause of severe diarrhea in infants and young children. RotaTeq, an oral, three-dose vaccine, is given to infants 6 to 32 weeks old.

The vaccine can be given during routine well-baby visits at 2, 4, and 6 months. On February 22, the Advisory Committee on Immunization Practices announced its decision to add RotaTeq to the Recommended Childhood and Adolescent Immunization Schedule.

FDA approval of RotaTeq is based on data from Merck's phase-III clinical trials of more than 70,000 infants, including the Rotavirus Efficacy and Safety Trial (REST), one of the largest prelicensing vaccine clinical trials ever conducted. In REST, RotaTeq reduced hospitalizations by 96% and emergency room visits by 94% for rotavirus gastroenteritis caused by serotypes targeted by the vaccine (G1, G2, G3, and G4) through the first two years after the third dose. Among infants observed in phase-III clinical trials, RotaTeq prevented 98% of severe cases of rotavirus gastroenteritis and prevented 74% of rotavirus gastroenteritis cases of any severity caused by serotypes targeted by the vaccine through the first full rotavirus season after vaccination.

"Virtually all children will experience rotavirus. While some children experience mild symptoms of rotavirus, infection can be severe and lead to dehydration that can be fatal," according to Paul Offit, MD, in a release prepared by Merck. Offit is chief of infectious diseases at The Children's Hospital of Philadelphia and co-inventor of the vaccine. "FDA approval of this vaccine is exciting for pediatricians because they will now have a way to help protect infants from rotavirus."

An earlier Wyeth-Lederle rotavirus vaccine, Rotashield, was withdrawn from use in 1999, not long after its introduction, when several cases of intestinal intussusception were reported in infants after they received the vaccine. No causal relationship was ever found between those cases and the vaccine. RotaTeq is a different formulation of rotavirus vaccine.