Group mean anti-PEDV IgA response in serum samples. The samples were collected at the day of initial vaccination (dpv 0), and dpv 7, 14, 21, 28, 35 and 42 and tested by an in house IgA PEDV ELISA. Pigs were exposed to live G1b PEDV at 3 weeks of age (dpv 0) or were vaccinated at 3 (dpv 0) and 5 (dpv 14) weeks of age with a commercial inactivated PEDV G2b vaccine. Pigs were challenged with PEDV G2b at 7 weeks of age (dpv 28/day post challenge or dpc 0). Data presented as mean group ELISA sample-to-positive (S/P) ratios ± SEM. Significantly different values for a dpc are indicated by different superscripts (A,B,C). The significance level was set to P < 0.05. Seropositive pigs/total number of pigs per group for groups that contained at least one seropositive pigs can be seen next to the group mean.