Volume 26, Number 9—September 2020
Research
Detection of H1 Swine Influenza A Virus Antibodies in Human Serum Samples by Age Group1
Table 7
Geometric mean of virus neutralization titers and antibody reactivity against different human and swine H1 influenza A viruses in different age groups of the population, 2017–2018, Belgium*
| Birth year range (age, y‡) | 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 | ||||
| 1920–6 (91–97) | 24 (8–68) | 67 (24–187) | 14 (8–25) | 17 (9–33) | 29 (13–65) | 29 (13–62) | 16 (9–28) | 18 (11–32) | 19 (10–37) | 170 (54–533) | 111 (49–254) | |||
| 1927–36 (81–90) | 13 (9–19) | 34 (19–58) | 38 (26–57) | 57 (39–84) | 27 (21–34) | 26 (17–40) | 14 (10–20) | 19 (12–27) | 20 (12–33) | 93 (63–135) | 101 (79–128) | |||
| 1937–46 (71–80) | 14 (8–23) | 31 (18–54) | 68 (39–118) | 98 (64–149) | 53 (41–68) | 36 (23–55) | 22 (13–35) | 17 (11–26) | 34 (23–50) | 42 (25–69) | 85 (55–133) | |||
| 1947–56 (61–70) | 11 (9–13) | 19 (12–30) | 29 (16–54) | 59 (38–93) | 36 (22–60) | 59 (34–102) | 30 (21–44) | 18 (12–26) | 19 (12–30) | 47 (27–83) | 73 (45–119) | |||
| 1957–66 (51–60) | 10 (10–10) | 20 (13–32) | 52 (37–72) | 80 (51–124) | 40 (28–58) | 36 (25–53) | 11 (9–13) | 11 (9–13) | 26 (14–47) | 52 (40–67) | 72 (45–116) | |||
| 1967–76 (41–50) | 11 (9–13) | 23 (14–36) | 41 (22–76) | 109 (76–158) | 27 (16–47) | 16 (10–26) | 11 (9–13) | 13 (9–19) | 24 (13–45) | 40 (22–74) | 38 (22–66) | |||
| 1977–86 (31–40) | 10 (10–10) | 14 (9–21) | 86 (55–137) | 81 (47–138) | 38 (22–65) | 27 (15–48) | 18 (11–30) | 13 (10–17) | 23 (14–37) | 35 (19–65) | 31 (16–60) | |||
| 1987–96 (21–30) | 10 (10–10) | 15 (10–24) | 41 (20–83) | 34 (18–64) | 46 (25–84) | 43 (23–78) | 13 (9–21) | 11 (9–13) | 35 (21–58) | 46 (31–67) | 47 (26–86) | |||
| 1997–2006 (11–20) | 15 (9–26) | 31 (15–64 | 17 (10–27) | 15 (10–22) | 53 (29–99) | 33 (20–55) | 10 (10–10) | 11 (9–14) | 40 (23–70) | 117 (54–256) | 149 (58–379) | |||
| 2007–17 (0–10) | 18 (9–37) | 37 (15–90) | 11 (9–15) | 12 (9–15) | 11 (9–14) | 10 (10–10) | 10 (10–10) | 10 (10–10) | 10 (10–10) | 70 (26–189) | 88 (35–221) | |||
| All (0–97) | 13
(11–14) |
25 (21–31) | 33 (28–40) | 44 (36–54) | 33 (28–39) | 28 (24–33) | 14 (13–16) | 13 (12–15) | 23 (20–27) | 60 (50–73) | 71 58–86) | |||
*Values expressed represent geometric mean virus neutralization titers of pooled serum samples per birth year (95% CI). Boldface indicates geometric mean VN titers of pooled serum samples per birth year. 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.
‡Age at the end of 2017.
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.