Volume 26, Number 9—September 2020
Research
Detection of H1 Swine Influenza A Virus Antibodies in Human Serum Samples by Age Group1
Table 8
Spearman correlation coefficients between hemagglutination inhibition antibody titers against human and swine H1 influenza A viruses (upper right) and between virus neutralization antibody titers against human and swine H1 influenza A viruses (lower left)*
Virus strain |
Eurasian avian |
Human seasonal |
Classical swine |
||||||||||
swG10 |
swHK11 |
TW86† |
swG12 |
NC99† |
swAL16 |
swIL10 |
swOK13 |
BR07† |
swOH07 |
CA09 |
|||
Europe 1C.2.1 |
Asia 1C.2.3 |
1B.1-like |
Europe 1B.1.2.1 |
1B.2-like |
N. Am. 1B.2.2.1 |
N. Am. 1B.2.2.2 |
N. Am. 1B.2.2.2 |
1B.2-like |
N. Am. 1A.3.3.3 |
World 1A.3.3.2 |
|||
swG10 | – | 0.68 | NS | 0.16 | 0.19 | 0.19 | NS | 0.26 | 0.18 | 0.56 | 0.55 | ||
swHK11 |
0.63 |
– |
0.24 |
0.26 |
0.32 |
0.31 |
0.23 |
0.43 |
0.30 |
0.68 |
0.63 |
||
TW86 | NS | NS | – | 0.84 | 0.52 | 0.43 | 0.21 | 0.35 | 0.35 | 0.25 | 0.26 | ||
swG12 |
NS |
NS |
0.77 |
– |
0.42 |
0.41 |
0.23 |
0.37 |
0.28 |
0.30 |
0.27 |
||
NC99 | NS | NS | 0.46 | 0.37 | – | 0.69 | 0.42 | 0.43 | 0.75 | 0.36 | 0.36 | ||
swAL16 | NS | NS | NS | NS | 0.71 | – | 0.53 | 0.38 | 0.58 | 0.43 | 0.39 | ||
swIL10 | NS | NS | NS | 0.37 | 0.39 | 0.52 | – | 0.37 | 0.45 | 0.30 | 0.26 | ||
swOK13 |
NS |
NS |
NS |
NS |
NS |
NS |
0.35 |
– |
0.39 |
0.33 |
0.34 |
||
BR07 |
NS |
NS |
NS |
NS |
0.76 |
0.57 |
NS |
NS |
– |
0.30 |
0.31 |
||
swOH07 | 0.55 | 0.67 | NS | NS | NS | NS | NS | NS | NS | – | 0.86 | ||
CA09 |
0.49 |
0.62 |
NS |
NS |
NS |
NS |
NS |
NS |
NS |
0.74 |
– |
||
*Viruses are ordered chronologically according to the year of circulation of the selected human test viruses TW86, NC99, BR07, and CA09; horizontal rules within table represent grouping of epidemiologically related human and swine influenza A viruses, with the oldest (ancestor) virus mentioned first. Complete isolate names are provided in Table 1. N. Am., North America; NS, not significant; –, not applicable. †Human IAV that no longer circulates; TW86 is the presumed human precursor for human-like H1 swine IAVs in Europe; NC99 is the presumed human precursor for human-like H1 swine IAVs in North America; BR07 is a human seasonal IAV that circulated right before the influenza A(H1N1)pdm09 virus; the influenza A(H1N1)pdm09 virus, represented by CA09, is circulating in both humans and swine worldwide. |
1Preliminary results from this study were presented at the Fourth International Symposium on Neglected Influenza Viruses, April 18–20, 2018, Brighton, United Kingdom; at the BELVIR conference, December 20, 2018, Brussels, Belgium; and at the 1918 Pandemic Conference, February 7–8, 2019, Ypres, Belgium.