Attenuated Poliovirus Sabin LsC 2ab Sabin type 1 (Panel A), P712 Ch 2ab Sabin type 2 (B) and Leon 12alb Sabin type 3 (C) infectious titers obtained on the indicated cell lines. Data are reported as TCID50/ml log10 mean ± standard error of the mean. Asterisk indicates a P value < 0.05 significance between the two data sets marked by the line.</p