Volume 26, Number 9—September 2020
Research
Detection of H1 Swine Influenza A Virus Antibodies in Human Serum Samples by Age Group1
Table 3
Cross-reactivity between human and swine H1 influenza A viruses in hemagglutination inhibition assay*
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 | 640 | 40 | <20 | <20 | <20 | <20 | <20 | <20 | <20 | <20 | 20 | ||
swHK11 |
640 |
640 |
<20 |
<20 |
<20 |
<20 |
<20 |
<20 |
<20 |
40 |
40 |
||
TW86 | <20 | <20 | 1,280 | 160 | 20 | <20 | <20 | <20 | <20 | <20 | <20 | ||
swG12 |
20 |
<20 |
160 |
1,280 |
20 |
20 |
<20 |
<20 |
<20 |
<20 |
<20 |
||
NC99 | <20 | <20 | <20 | <20 | 640 | <20 | <20 | <20 | 80 | <20 | <20 | ||
swAL16 | <20 | <20 | <20 | <20 | 160 | 320 | 20 | <20 | 20 | <20 | <20 | ||
swIL10 | <20 | <20 | <20 | <20 | 40 | 40 | 320 | <20 | 160 | <20 | <20 | ||
swOK13 |
<20 |
<20 |
<20 |
<20 |
<20 |
<20 |
<20 |
640 |
<20 |
<20 |
<20 |
||
BR07 |
<20 |
<20 |
<20 |
<20 |
40 |
<20 |
<20 |
<20 |
1,280 |
<20 |
<20 |
||
swOH07 | 20 | 40 | <20 | <20 | <20 | <20 | <20 | 20 | <20 | 1,280 | 640 | ||
CA09 |
20 |
20 |
<20 |
<20 |
<20 |
<20 |
<20 |
<20 |
<20 |
160 |
1,280 |
||
*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. Bold indicates HI titer against the homologous virus. IAV, influenza A virus; HI, hemagglutination inhibition; N. Am., North America. †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.