The authors then analyzed nAbs to RV-A7, RV-A16, RV-A36, and the three RV-Cs in plasma from 20 COAST study participants, measured at 2, 10, and 16 years.At age 2, only 5% of samples had nAbs to any of the three RV-As, whereas 27% had nAbs to the three RV-Cs.The low frequencies of nAbs against the RV-As may also have been skewed by unexpectedly low frequencies of titers against RV-A16 at age 16, as these were only 10%, considerably lower than at age 10 and against RV-A36 at age 16 (both 35%).Thus, more representative frequencies for RV-A strains would likely be ∼35% at age 10 and ∼35% or higher at age 16.I congratulate the authors for performing these extensive and detailed investigations and for significantly extending our understanding of RV species in childhood.