The present disclosure is directed to novel porcine sapoviruses (SaV) isolates, including SaV serially propagated in cell culture, all of which are useful in the preparation of immunogenic compositions and vaccines for treating and preventing disease in swine. The disclosure further provides characterization of pathogenicity and cross-protective immunity of contemporary porcine SaV isolates in weaned pigs, demonstrating that prior exposure to homologous strains provides greater protection against viral shedding than heterologous strains.