Development of a rotavirus vaccine: Clinical safety, immunogenicity, and efficacy of the pentavalent rotavirus vaccine, RotaTeq ®

Abstract

Initial approaches for rotavirus vaccines were based on the classical “Jennerian” approach and utilized simian and bovine rotavirus strains, which provided cross-protection against human rotavirus strains but did not cause illness in infants and young children because of their species-specific tropism. The demonstrated efficacy of these vaccines was not consistent across studies. Thus, human–animal reassortants containing an animal rotavirus backbone with human rotavirus surface G and/or P proteins were developed, which demonstrated more consistent efficacy than that observed with the non-reassortant rotavirus strains. The pentavalent rotavirus vaccine, RotaTeq ®, contains 5 human-bovine reassortant rotaviruses consisting of a bovine (WC3) backbone with human rotavirus surface proteins representative of the most common G (G1, G2, G3, G4) or P (P1A[8]) types worldwide. The present review focuses on the development of the pentavalent rotavirus vaccine RotaTeq ®. Results of a large-scale Phase III clinical study showed that three doses of RotaTeq ® were immunogenic, efficacious, and well tolerated with no increased clinical risk of intussusception. RotaTeq ® was efficacious against rotavirus gastroenteritis of any severity (74%) and severe disease (98–100%), using a validated clinical scoring system. Reductions in rotavirus-associated hospitalizations and emergency department (ED) visits, for up to 2 years post-vaccination, were 95% in Europe, 97% in the United States, and 90% in the Latin American/Caribbean regions. RotaTeq ® was recently shown to be up to 100% effective in routine use in the US in reducing hospitalizations and ED visits and 96% effective in reducing physician visits. Additional studies in 8 different locations in the US have shown 85–95% reduction in rotavirus-associated hospitalizations and/or ED visits in the first 2–2.5 years of routine use.