Vaccine – Volume 35, Issue 5, Pages 713-850 (1 February 2017)

Vaccine
Volume 35, Issue 5, Pages 713-850 (1 February 2017)
http://www.sciencedirect.com/science/journal/0264410X/35/5

Regular paper

Evaluating the first introduction of rotavirus vaccine in Thailand: Moving from evidence to policy
Original Research Article
Pages 796-801
Piyanit Tharmaphornpilas, Suchada Jiamsiri, Somchit Boonchaiya, Onwipa Rochanathimoke, Wiravan Thinyounyong, Sumana Tuntiwitayapun, Ratigorn Guntapong, Arthorn Riewpaiboon, Aim-on Rasdjarmrearnsook, Roger I. Glass

Abstract
Background
We assessed the effectiveness and possible impact of introducing rotavirus vaccine into the routine immunization program.

Methods
Two provinces were selected for an observational study, one where vaccine was introduced and another where vaccine was not available. In these areas, two sub-studies were linked. The prospective cohort study enrolled children 2 month old and followed them to the age of 18 months to detect all diarrhea episodes. The hospital surveillance study enrolled all children up to age 5 hospitalized with diarrhea whose fecal samples were tested for rotavirus. Rates of rotavirus hospitalizations in older children who had not been vaccinated in both settings provided data to determine whether immunization had an indirect herd effect. The key endpoints for the study were both vaccine effectiveness (VE) based upon hospitalized rotavirus diarrhea and herd protection.

Findings
From the cohort study, the overall VE for hospitalized rotavirus diarrhea was 88% (95%CI 76–94). Data from hospital surveillance indicated that for 2 consecutive years, the seasonal peak of rotavirus admissions was no longer present in the vaccinated area. Herd protection was observed among older children born before the rotavirus vaccine program was introduced, who experienced a 40–69% reduction in admission for rotavirus.

Conclusions
Rotavirus vaccine was highly effective in preventing diarrheal hospitalizations and in conferring herd protection among older children who had not been vaccinated.