Supplemental Material: High serological barriers may contribute to restricted Influenza-A-virus transmission between pigs and humans

Human-to-swine (reverse zoonotic) transmission of seasonal and pandemic human influenza A viruses (IAV) to pigs primarily replenishes the vast reservoir of genetically and antigenically heterogeneous swine (sw) IAV maintained in domestic pigs worldwide. Sporadic but regularly observed cases of pig-to-human (zoonotic) infections with swIAV tend to be discovered by chance, with children being affected disproportionately often.

Here, a total of 3070 porcine and 333 human nasal swab samples from 135 swine farms in Germany were investigated for IAV by real time RT-PCR and full genome sequencing. In addition, swIAV sequences generated in the frame of this study were analyzed to determine potential mutations for human MxA and BTN3A3 escape. 

01_Table S1: Summary of information of swine holdings and RT-qPCR results. 1 indicates applicable; 0 indicates not applicable; n.d. indicates not determined.

02_Table S2: Summary of information about human samples and. 1 indicates applicable; 0 indicates not applicable; n.d. indicates not determined.

03_Table S3: A. Comparison of relevant mutations in the genome of MWP/21, swine-MWP/21, and NRW/22 generated by Flusurver (http://flusurver.bii.a-star.edu.sg). 1 indicates the presence of mutation(s), 0 indicates the absence of those mutation(s). B. Visualization of the AA differences of affected segments of the zoonotic case MWP/21 and the corresponding sequence (sw-MWP/21) generated from pigs of the related herd. 

04_Table S4: Accession number (EPI_ISL) of sequences analyzed in the frame of this study. All sequences are available on GISAID EpiFLU.

05_Table S5: Amino acids on positions in the nucleoprotein (NP) sequence associated with MxA resistance and BTN3A3 resistance of selected swIAV NP sequences. "av) indicates genome segments phylogenetically associated with the avian-derived H1 (1C), "pdm" indicates those of the human pandemic A/H1N1 2009 lineage (1A). 

06_Figure S1:  Phylogenic tree of swIAV H1 HA gene of the clades 1A, 1B and 1C annotated by global H1-lineage nomenclature by Anderson et al. (2016). Swine derived swIAV sequences generated in the frame of this study are colored in red, zoonotic cases MWP/21 and NRW/22 are colored in green.  The reverse-zoonotic case is highlighted in violet with its closest related human sequence colored in green.

07_Material and Methods: Description of material used and specification of applied methods in the frame of this study.

08_Questinonaire human participants: Questionaire used in the frame of this study.

09_Questinonaire swine farms: Questionaire used in the frame of this study.