Immunogenicity nOPV2 With and Without bOPV

nOPV2 candidate 1 (S2/cre5/S15domV/rec1/hifi3) is a live-attenuated serotype-2 poliovirus that was derived from a modified Sabin type-2 infectious cDNA clone and propagated in Vero cells. To improve genetic stability, nucleotide sequence modifications were made in the major determinant for attenuation in the Sabin 5'-untranslated region. Additionally, two modifications in the polymerase 3D were made to further improve stability of the attenuation, and a key replication element from the 2C coding region was relocated to the 5'-untranslated region to inhibit recombination.

The live types 1 \& 3 oral polio vaccine (bOPV) is a bivalent vaccine containing suspension of types 1 \& 3 attenuated Polio viruses (Sabin strains).