Due to their error-prone RNA polymerase, RNA viruses are subject to constant evolution. The error rate of picornavirus RNA polymerases has been estimated to range between 10 23 and 10 24 errors/nucleotide/cycle of replication [26, 27] . This variability is a driving force for virus evolution. The number of genera, species, and serotypes illustrates this diversity (http://www.picornaviridae. com) with at least 74 HRV-A and 25 HRV-B serotypes identified, and 61 HRV-C types proposed [22] .