Table 2. Genetic characteristics of influenza viruses as reported to TESSy by week of sampling, WHO European Region, week 40 2019–week 20 2020 (n = 3,403 viruses characterised in 21 countries).
| Year and week |
Influenza B | Influenza A | TOTAL | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yamagataa | Victoriaa | H1a | H3a | ||||||||||||||
| Subgroup not listed |
3b
_ B/ Phuket/3073/2013 |
Subgroup not listed |
1A(Δ162-164)Β_ B/ Washington /02/2019c |
No clade |
1Α(Δ162-163) _ B/ Colorado/06/2017d |
1A(Δ162-164) _ B/ Hong Kong/269/2017 |
Subgroup not listed |
6Β.1Α7 _ A/ Slovenia/1489/2019 |
6Β.1Α1 _ A/ Brisbane/02/2018e |
6Β.1Α5Α _ A/ Norway/3433 /2018 |
6Β.1Α5Β _ A/ Switzerland/3330/2018 |
3C.2a1b +T131K- B _ A/ South Australia/34/19f |
3C.3a _ A/ Kansas/14/2017g |
3C.2a1b +T135K _ A/ La Rioja/2202/2018 |
3C.2a1b +T135K-B _ A/ Hong Kong/2675/19 |
||
| 2019 | |||||||||||||||||
| 40 | 0 | 0 | 0 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 1 | 4 | 7 | 1 | 2 | 23 |
| 41 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 0 | 0 | 6 | 0 | 10 | 5 | 1 | 1 | 25 |
| 42 | 0 | 0 | 0 | 4 | 0 | 1 | 0 | 0 | 0 | 0 | 9 | 0 | 9 | 2 | 1 | 1 | 27 |
| 43 | 0 | 1 | 0 | 5 | 0 | 0 | 0 | 0 | 0 | 0 | 6 | 1 | 13 | 4 | 2 | 4 | 36 |
| 44 | 0 | 1 | 0 | 9 | 0 | 0 | 0 | 0 | 0 | 0 | 17 | 3 | 12 | 13 | 0 | 7 | 62 |
| 45 | 0 | 0 | 0 | 13 | 0 | 0 | 0 | 1 | 0 | 0 | 12 | 8 | 10 | 19 | 2 | 4 | 69 |
| 46 | 0 | 0 | 0 | 17 | 0 | 1 | 0 | 1 | 0 | 0 | 27 | 6 | 5 | 17 | 2 | 3 | 79 |
| 47 | 0 | 2 | 1 | 32 | 0 | 0 | 0 | 0 | 1 | 1 | 23 | 2 | 24 | 22 | 3 | 9 | 120 |
| 48 | 0 | 7 | 1 | 50 | 1 | 1 | 0 | 1 | 0 | 1 | 34 | 1 | 20 | 25 | 2 | 10 | 154 |
| 49 | 1 | 2 | 2 | 41 | 0 | 2 | 1 | 0 | 1 | 3 | 40 | 2 | 20 | 46 | 2 | 5 | 168 |
| 50 | 0 | 3 | 3 | 63 | 0 | 0 | 0 | 4 | 2 | 0 | 55 | 2 | 15 | 41 | 3 | 4 | 195 |
| 51 | 1 | 2 | 0 | 60 | 0 | 7 | 0 | 1 | 2 | 4 | 51 | 1 | 21 | 60 | 11 | 8 | 229 |
| 52 | 0 | 1 | 1 | 47 | 0 | 3 | 2 | 1 | 1 | 2 | 56 | 2 | 26 | 53 | 6 | 7 | 208 |
| 2020 | |||||||||||||||||
| 1 | 0 | 3 | 2 | 47 | 0 | 1 | 0 | 5 | 1 | 7 | 95 | 3 | 31 | 37 | 3 | 6 | 241 |
| 2 | 0 | 3 | 6 | 48 | 0 | 0 | 0 | 4 | 6 | 1 | 123 | 4 | 27 | 39 | 5 | 5 | 271 |
| 3 | 0 | 1 | 2 | 92 | 0 | 2 | 0 | 0 | 5 | 2 | 170 | 6 | 25 | 63 | 7 | 7 | 382 |
| 4 | 0 | 0 | 4 | 41 | 0 | 0 | 0 | 0 | 3 | 0 | 98 | 3 | 16 | 35 | 11 | 3 | 214 |
| 5 | 0 | 1 | 11 | 40 | 0 | 1 | 1 | 0 | 0 | 0 | 92 | 2 | 17 | 46 | 6 | 3 | 220 |
| 6 | 0 | 0 | 5 | 41 | 0 | 0 | 1 | 1 | 0 | 3 | 55 | 3 | 20 | 47 | 4 | 4 | 184 |
| 7 | 0 | 1 | 2 | 41 | 0 | 1 | 0 | 0 | 1 | 0 | 48 | 2 | 23 | 31 | 5 | 0 | 155 |
| 8 | 0 | 0 | 0 | 21 | 0 | 0 | 0 | 0 | 0 | 0 | 26 | 0 | 5 | 18 | 0 | 0 | 70 |
| 9 | 0 | 0 | 0 | 19 | 0 | 0 | 0 | 1 | 0 | 2 | 21 | 0 | 4 | 15 | 2 | 1 | 65 |
| 10 | 0 | 0 | 0 | 25 | 0 | 0 | 0 | 2 | 0 | 2 | 30 | 0 | 7 | 18 | 1 | 0 | 85 |
| 11 | 0 | 0 | 0 | 27 | 0 | 1 | 0 | 0 | 0 | 0 | 14 | 0 | 11 | 12 | 1 | 0 | 66 |
| 12 | 0 | 0 | 0 | 15 | 0 | 0 | 0 | 0 | 0 | 0 | 8 | 0 | 7 | 3 | 0 | 0 | 33 |
| 13 | 0 | 0 | 0 | 11 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 0 | 4 | 1 | 0 | 0 | 18 |
| 14 | 0 | 0 | 0 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 3 |
| 15 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
| 16 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 17 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 18 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 19 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 20 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Total | 2 | 28 | 40 | 819 | 1 | 22 | 5 | 22 | 23 | 28 | 1,121 | 52 | 386 | 679 | 81 | 94 | 3,403 |
TESSy: The European Surveillance System; WHO: World Health Organization.
a For influenza B viruses of the Yamagata lineage, no viruses were reported as not belonging to a predefined genetic clade (‘no clade’), while for influenza B viruses of the Victoria lineage, no viruses of clade 1A without amino-acid deletions, represented by the B/Brisbane/60/2008, were detected. For influenza A(H1) no viruses were reported as ‘no clade’ and no viruses were detected as being part of subclade 6B.1A6, represented by A/Ireland/84630/2018. For influenza A(H3) no viruses were reported with ‘no clade’ and no viruses had a ‘subgroup not listed’.
b Vaccine component in quadrivalent both northern (2019/20 season) and southern (2020 season) hemispheres.
c Vaccine component for the southern hemisphere 2020 season.
d Vaccine component for use in northern hemisphere 2019/20 season.
e Vaccine component for both northern (2019/20 season) and southern (2020 season) hemispheres.
f Vaccine component for the southern hemisphere 2020 season.
g Vaccine component for the northern hemisphere 2019/20 season.