Fig. 3From: Recombinant tandem epitope vaccination provides cross protection against Actinobacillus pleuropneumoniae challenge in miceThe serum antibody level of the mice in all groups was detected by indirect ELISA. Each group had 6 mice. aAPP1 was used as the coating antigen. bAPP5b was used as the coating antigen. c1 At day 28 of immunization, the antibody level of the mice in all groups was detected by indirect ELISA. c2 At day 35 of immunization, the antibody level of the mice in all groups was detected by indirect ELISABack to article page