Interference Between Enteric Viruses and Live-Attenuated Rotavirus Vaccine Virus in a Healthy Australian Birth Cohort

Background Rotavirus vaccines have reduced effectiveness in high-mortality settings. Interference between enteric viruses and live-attenuated oral vaccine strains may be a factor. Methods In a birth cohort of healthy Australian infants, parents collected weekly stool samples. Three hundred eighty-one paired swabs collected within 10-days of RotaTeq vaccination from 140 infants were tested for 10 enteric viruses and RotaTeq strains. Results Collectively, both ribonucleic acid and deoxyribonucleic acid viruses were negatively associated with RotaTeq shedding (adjusted odds ratio = 0.29, 95% confidence interval = 0.14-0.58 and adjusted odds ratio = 0.30, 95% confidence interval = 0.11-0.78, respectively). Conclusions Enteric viruses may interfere with RotaTeq replication in the gut and thus RotaTeq stool shedding. RNA and DNA enteric viruses present in stools immediately before RotaTeq vaccination were negatively associated with RotaTeq shedding, suggesting decreased vaccine virus replication. Viral interference may be a contributing factor to decreased rotavirus vaccine performance in high child mortality countries.