Fig 1.
Overview on the timeline of the study in relation to IAV occurrence and vaccination (1A) and the study design (1B).
Table 1.
Number of pigs testing positive for IAV in nasal swabs in the different batches at week 1, 3, 5 and 10–12 during the 1st and 2nd sampling.
Fig 2.
The percentage of seropositive sows and pigs and the summed percentage of the number of pigs testing positive for IAV in nasal swabs at the 1st (2A) and 2nd (2B) sampling round.
The columns shows the percentage of seropositive sow and pigs. The blood samples were collected 2 weeks before farrowing from the sows and at week 3 and week 10–12 from the pigs born from the sampled sows. The red line show the summed percentage of pigs at each sampling time (week 1, 3, 5 and 10–12) testing positive for IAV in nasal swabs. “2A” presents the results of the 1st sampling round (before mass sow vaccination), and “2B” presents the results of the 2nd sampling (after mass sow vaccination).
Table 2.
Prolonged shedders, total number of infected individuals and Ct values of the 1st and 2nd sampling.
Table 3.
Differences in mean coughing index between the 1st and 2nd sampling round.
Table 4.
Differences in the number of IAV positive and negative animals with nasal discharge between the 1st and 2nd sampling.
Fig 3.
Alignment of HA proteins obtained at screening, the 1st and 2nd sampling round and from the vaccine strain (Haselünne/IDT2617/2003 (H1N1)).
Dots indicate identical amino acids among the HA proteins, whereas a green background indicates differences between at least one of the four HA proteins. The colored underlines represent the five antigenic sites Sa (purple), Sb (green), Ca1 (blue), Ca2 (orange) and Cb (red).
Table 5.
Identification of positively selected sites of the HA gene by MrBayes and CODEML.
Fig 4.
Results of hemagglutination inhibition (HI) test of sow sera collected during the 1st (left) and 2nd (right) sampling round.
Each sow sera was tested against three different virus: P5-U4 (A/sw/Denmark/P5U4/2016(H1N1)) isolated from a pig sampled during the screening; HB4 (A/sw/Denmark/HB4280U1/2017(H1N2)) sampled from a pig during the 1st sampling round and before vaccination and VB4 (A/sw/Denmark/VB4379U3/2017(H1N2)) collected during the 2nd sampling round after start of mass sow vaccination. Negative samples were samples with a HI titer below 20.