Symptoms associated with rhesus-human reassortant rotavirus vaccine in infants

Background. Severe rotavirus gastroenteritis is potentially preventable by oral rhesus-human reassortant tetravalent (RRV-TV) vaccine, which may soon be licensed in the US and Europe. The objective of this study was to evaluate symptoms associated with the high titer RRV-TV vaccine given concurrently with routine childhood immunizations. Methods. In a randomized placebo-controlled double blind trial of RRV-TV vaccine titer 4 x 10(5) plaque-forming units vs. placebo, 2282 children received all 3 doses of study vaccine between ages 2 and 7 months. Symptoms were followed by parents who also took daily rectal temperatures. Results. On days 3 to 5 after the first dose of vaccine fever 38.0 degrees C or greater was detected in 387 of 1182 (33%) infants in the RRV-TV vaccine group vs. 27 of 1194 (2.3%) infants in the placebo groups (P < 0.001) and fever 39.0 degrees C or greater was detected in 40 (3.4%) and 3 (0.2%) infants in the vaccine and placebo groups, respectively (P < 0.001). Irritability, decreased appetite and abdominal cramping on Days 3 to 5 postvaccination were also more common in the RRV-TV vaccine recipients than in the placebo recipients. One child in the RRV-TV group was hospitalized and 2 more infants seen in the clinic, vs. none in the placebo group, within the 5-day period after the first dose for a reason probably related to the RRV-TV vaccine. After the second and third doses of RRV-TV vaccine, there were only minor differences between the vaccine and placebo recipients in fever on Days 3 to 5 postvaccination. Conclusions. The first dose of RRV-TV vaccine is associated with a relatively high rate of febrile and other reactions, which may require a physician visit and, rarely, hospitalization.