TABLE 2.
Seroprevalence of protective antibodies (HAI ≥ 40) against influenza A(H1N1)pdm09, A(H3N2), B/Victoria, and B/Yamagata and ratio by age group, between 2014 and 2019, in Portugal (0–4 year old group was considered reference to ratio calculation).
| Age group (n) | AH1 seroprev % (n) (95% CI) | AH1 ratio (95% CI) | AH3 seroprev % (n) (95% CI) | AH3 ratio (95% CI) | B_Victoria seroprev % (n) (95% CI) | B_Victoria ratio (95% CI) | B_Yamagata seroprev % (n) (95% CI) | B_Yamagata ratio (95% CI) | |
|---|---|---|---|---|---|---|---|---|---|
| 2014 | Overall (626) |
26.5 (186) (22.2–31.4) |
36.3 (250) (31.2–41.9) |
10.4 (57) (7.7–13.6) |
27.2 (144) (22.5–32.4) |
||||
|
0–4 (119) |
33.6 (40) (25.2–42.8) |
Ref. |
40.3 (48) (31.4–49.7) |
Ref. |
1.7 (2) (0.2–5.9) |
Ref. |
7.6 (9) (3.5–13.9) |
Ref. | |
|
5–14 (124) |
46 (57) (37.0–55.1) |
1.4 (1.0–1.9) |
59.7 (74) (50.5–68.4) |
1.5 (1.1–1.9) |
6.5 (8) (2.8–12.3) |
3.8 (0.8–17.7) |
18.5 (23) (12.1–26.5) |
2.5 (1.2–5.1) |
|
|
15–44 (129) |
24.8 (32) (17.6–33.2) |
0.7 (0.5–1.1) |
34.9 (45) (26.7–43.8) |
0.9 (0.6–1.2) |
7 (9) (3.2–12.8) |
4.2 (0.9–18.8) |
33.3 (43) (25.3–42.2) |
4.4 (2.2–8.6) |
|
|
45–64 (129) |
23.3 (30) (16.3–31.5) |
0.7 (0.5–1.0) |
24 (31) (16.9–32.3) |
0.6 (0.4–0.9) |
15.5 (20) (9.7–22.9) |
9.2 (2.2–38.6) |
20.9 (27) (14.3–29) |
2.8 (1.4–5.6) |
|
|
65+ (125) |
21.6 (27) (14.7–29.8) |
0.6 (0.4–1.0) |
41.6 (52) (32.9–50.8) |
1 (0.8–1.4) |
14.4 (18) (8.8–21.8) |
8.6 (2.0–36.1) |
33.6 (42) (25.4–42.6) |
4.4 (2.3–8.7) |
|
| 2015 | Overall (680) |
12.1 (85) (9.3–15.3) |
20.8 (149) (17–24.9) |
8.0 (47) (5.7–10.8) |
14.6 (87) (11.4–18.3) |
||||
|
0–4 (128) |
6.3 (8) (2.7–11.9) |
Ref. |
21.9 (28) (15.1–30) |
Ref. |
1.6 (2) (0.2–5.5) |
Ref. |
4.7 (6) (1.7–9.9) |
Ref. | |
|
5–14 (132) |
23.5 (31) (16.5–31.6) |
3.8 (1.8–7.9) |
30.3 (40) (22.6–38.9) |
1.4 (0.9–2.1) |
4.5 (6) (1.7–9.6) |
2.9 (0.6–14.1) |
12.1 (16) (7.1–18.9) |
2.6 (1–6.4) |
|
|
15–44 (140) |
10.7 (15) (6.1–17.1) |
1.7 (0.8–3.9) |
22.1 (31) (15.6–29.9) |
1 (0.6–1.6) |
7.1 (10) (3.5–12.7) |
4.6 (1.0–20.5) |
16.4 (23) (10.7–23.6) |
3.5 (1.5–8.3) |
|
|
45–64 (140) |
11.4 (16) (6.7–17.9) |
1.8 (0.8–4.1) |
13.6 (19) (8.4–20.4) |
0.6 (0.4–1.1) |
9.3 (13) (5.0–15.4) |
5.9 (1.4–25.8) |
13.6 (19) (8.4–20.4) |
2.9 (1.2–7) |
|
|
65+ (140) |
10.7 (15) (6.1–17.1) |
1.7 (0.8–3.9) |
22.1 (31) (15.6–29.9) |
1 (0.6–1.6) |
11.4 (16) (6.7–17.9) |
7.3 (1.7–31.2) |
16.4 (23) (10.7–23.6) |
3.5 (1.5–8.3) |
|
| 2016 | Overall (708) |
36.3 (265) (31.4–41.6) |
33.0 (263) (28.5–37.9) |
44.3 (323) (39–50.1) |
32.0 (222) (27.5–37.1) |
||||
|
0–4 (128) |
32.8 (42) (24.8–41.7) |
Ref. |
34.4 (44) (26.2–43.3) |
Ref. |
39.1 (50) (30.6–48.1) |
Ref. |
23.4 (30) (16.4–31.7) |
Ref. | |
|
5–14 (143) |
55.2 (79) (46.7–63.6) |
1.7 (1.3–2.2) |
62.2 (89) (53.8–70.2) |
1.8 (1.4–2.4) |
55.2 (79) (46.7–63.6) |
1.4 (1.1–1.8) |
33.6 (48) (25.9–41.9) |
1.4 (1.0–2.1) |
|
|
15–44 (146) |
37.7 (55) (29.8–46.1) |
1.1 (0.8–1.6) |
29.5 (43) (22.2–37.6) |
0.9 (0.6–1.2) |
39 (57) (31.1–47.5) |
1 (0.7–1.3) |
31.5 (46) (24.1–39.7) |
1.3 (0.9–2.0) |
|
|
45–64 (147) |
33.3 (49) (25.8–41.6) |
1 (0.7–1.4) |
22.4 (33) (16.0–30.1) |
0.7 (0.4–1.0) |
43.5 (64) (35.4–52) |
1.1 (0.8–1.5) |
29.3 (43) (22.0–37.3) |
1.2 (0.8–1.9) |
|
|
65+ (144) |
27.8 (40) (20.6–35.8) |
0.8 (0.6–1.2) |
37.5 (54) (29.6–45.9) |
1.1 (0.8–1.5) |
50.7 (73) (42.2–59.1) |
1.3 (1.0–1.7) |
38.2 (55) (30.2–46.7) |
1.6 (1.1–2.4) |
|
| 2017 | Overall (867) |
15.0 (138) (12.3–18.0) |
35.7 (344) (31.5–40.2) |
9.4 (78) (7.3–11.9) |
19.7 (159) (16.5–23.4) |
||||
|
0–4 (151) |
15.9 (24) (10.5–22.7) |
Ref. |
37.1 (56) (29.4–45.3) |
Ref. |
4.6 (7) (1.9–9.3) |
Ref. |
9.9 (15) (5.7–15.9) |
Ref. | |
|
5–14 (155) |
23.2 (36) (16.8–30.7) |
1.5 (0.9–2.3) |
72.9 (113) (65.2–79.7) |
2 (1.6–2.5) |
9.7 (15) (5.5–15.5) |
2.1 (0.9–5.0) |
18.1 (28) (12.4–25.0) |
1.8 (1.0–3.3) |
|
|
15–44 (185) |
13 (24) (8.5–18.7) |
0.8 (0.5–1.4) |
31.4 (58) (24.7–38.6) |
0.8 (0.6–1.1) |
6.5 (12) (3.4–11.1) |
1.4 (0.6–3.5) |
20 (37) (14.5–26.5) |
2.0 (1.1–3.5) |
|
|
45–64 (188) |
15.4 (29) (10.6–21.4) |
1 (0.6–1.6) |
25 (47) (19.0–31.8) |
0.7 (0.5–0.9) |
15.4 (29) (10.6–21.4) |
3.3 (1.5–7.4) |
20.7 (39) (15.2–27.2) |
2.1 (1.2–3.6) |
|
|
65+ (188) |
13.3 (25) (8.8–19) |
0.8 (0.5–1.4) |
37.2 (70) (30.3–44.6) |
1 (0.8–1.3) |
8 (15) (4.5–12.8) |
1.7 (0.7–4.1) |
21.3 (40) (15.7–27.8) |
2.1 (1.2–3.7) |
|
| 2018 | Overall (566) |
35.0 (215) (29.7–40.9) |
45.8 (287) (39.7–52.4) |
32.4 (169) (27.2–38.3) |
52.1 (277) (45.3–59.4) |
||||
|
0–4 (113) |
40.7 (46) (31.6–50.4) |
Ref. |
50.4 (57) (40.9–60.0) |
Ref. |
13.3 (15) (7.6–20.9) |
Ref. |
34.5 (39) (25.8–44.0) |
Ref. | |
|
5–14 (112) |
53.6 (60) (43.9–63) |
1.3 (1.0–1.7) |
82.1 (92) (73.8–88.7) |
1.6 (1.3–2.0) |
34.8 (39) (26.1–44.4) |
2.6 (1.5–4.5) |
51.8 (58) (42.1–61.3) |
1.5 (1.1–2.0) |
|
|
15–44 (113) |
34.5 (39) (25.8–44) |
0.8 (0.6–1.2) |
44.2 (50) (34.9–53.9) |
0.9 (0.7–1.2) |
31 (35) (22.6–40.4) |
2.3 (1.4–4.0) |
56.6 (64) (47.0–65.9) |
1.6 (1.2–2.2) |
|
|
45–64 (117) |
28.2 (33) (20.3–37.3) |
0.7 (0.5–1.0) |
33.3 (39) (24.9–42.6) |
0.7 (0.5–0.9) |
35 (41) (26.5–44.4) |
2.6 (1.6–4.5) |
46.2 (54) (36.9–55.6) |
1.3 (1–1.8) | |
|
65+ (111) |
33.3 (37) (24.7–42.9) |
0.8 (0.6–1.2) |
44.1 (49) (34.7–53.9) |
0.9 (0.7–1.2) |
35.1 (39) (26.3–44.8) |
2.6 (1.6–4.5) |
55.9 (62) (46.1–65.3) |
1.6 (1.2–2.2) | |
| 2019 | Overall (879) |
49.6 (447) (44.3–55.2) |
28.0 (259) (24.2–32.2) |
40.9 (337) (36.2–46.1) |
32.6 (246) (28.2–37.5) |
||||
|
0–4 (161) |
50.3 (81) (42.3–58.3) |
Ref. |
26.7 (43) (20.1–34.2) |
Ref. |
26.7 (43) (20.1–34.2) |
Ref. |
10.6 (17) (6.3–16.4) |
Ref. | |
|
5–14 (178) |
71.3 (127) (64.1–77.9) |
1.4 (1.2–1.7) |
48.5 (80) (40.6–56.4) |
1.8 (1.3–2.5) |
31.5 (56) (24.7–38.8) |
1.2 (0.8–1.6) |
37.1 (66) (30.0–44.6) |
3.5 (2.2–5.7) |
|
|
15–44 (180) |
58.9 (106) (51.3–66.2) |
1.2 (1–1.4.0) |
26.7 (47) (20.3–33.9) |
1 (0.7–1.4) |
38.3 (69) (31.2–45.9) |
1.4 (1–2) |
48.3 (87) (40.8–55.9) |
4.6 (2.8–7.4) |
|
|
45–64 (180) |
34.4 (62) (27.5–41.9) |
0.7 (0.5–0.9) |
22.2 (40) (16.4–29) |
0.8 (0.6–1.2) |
46.7 (84) (39.2–54.2) |
1.7 (1.3–2.4) |
20.6 (37) (14.9–27.2) |
1.9 (1.1–3.3) |
|
|
65+ (180) |
39.4 (71) (32.3–47) |
0.8 (0.6–1.0) |
27.2 (49) (20.9–34.3) |
1 (0.7–1.4) |
47.2 (85) (39.8–54.8) |
1.8 (1.3–2.4) |
21.7 (39) (15.9–28.4) |
2.1 (1.2–3.5) |