Reagent update
Current availability from MHRA of candidate influenza vaccine viruses, SRD reagents and neuraminidase reagents for use in the 2026 southern hemisphere season and in the 2025-26 northern hemisphere season (see below for pricing information).
More information can be found in the Influenza Resource Centre pages
Update 165 - 14 November 2025
Candidate influenza viruses for use in the southern hemisphere 20261
Candidate influenza vaccine viruses
|
NIBSC code
|
|
H1N1
|
|
|
A/Switzerland/6849/2025
|
25/234
|
|
IVR-278 reassortant derived from A/Switzerland/6849/2025
|
25/240
|
|
A/Missouri/11/2025
|
25/236
|
|
IVR-279 reassortant derived from A/Missouri/112025
|
25/242
|
|
H3N2
|
|
|
A/Singapore/GP20238/2024
|
25/232
|
|
IVR-277 reassortant derived from A/Singapore/GP20238/2024
|
25/238
|
|
A/Valladolid/1187/2025
|
25/244
|
|
B (Victoria lineage)
|
|
|
B/Austria/1359417/2021
|
23/228
|
|
BVR-26 reassortant derived from B/Austria/1359417/2021
|
25/264
|
|
BX-107A reassortant derived from B/Austria/1359417/2021
|
22/134
|
|
B/Michigan/01/2021
|
21/244
|
|
B/Singapore/WUH4618/2021
|
21/242
|
|
B/Guangdong-Zhenjiang/1516/2021
|
21/388
|
|
|
1 Recommended composition of influenza virus vaccines for use in the 2026 southern hemisphere influenza season
Access To B/Yamagata lineage viruses is currently restricted.
Please contact Othmar.Engelhardt@mhra.gov.uk and Jason.Long@mhra.gov.uk
SRD reagents for use in the southern hemisphere 20261
Reagents for influenza vaccine standardisation
|
NIBSC code
|
|
H1N1
|
|
|
A/Switzerland/6849/2025 (IVR-278) antigen
|
25/222
|
|
A/Missouri/11/2025 - like antiserum
|
25/224
|
|
H3N2
|
|
|
A/Singapore/GP20238/2024 (IVR-277) antigen
|
25/220
|
|
A/Singapore/GP20238/2024 - like antiserum
|
25/226
|
|
B (Victoria lineage)
|
|
|
B/Austria/1359417/2021 (BVR-26) antigen
|
24/180
|
|
B/Michigan/01/2021 antigen
|
21/330
|
|
B/Singapore/WUH4618/2021 (cell derived) antigen
|
23/268
|
|
B/Austria/1359417/2021 - like antiserum
|
24/118
|
|
B (Yamagata lineage)
|
|
|
B/Phuket/3073/2013 antigen
|
21/136
24/182
|
|
B/Utah/9/2014 (cell derived) antigen
|
15/100
|
|
B/Singapore/INFTT-16-0610/2016 (cell derived) antigen
|
19/308
|
|
B/Phuket/3073/2013 - like antiserum
|
22/132
|
1Recommended composition of influenza virus vaccines for use in the 2026 southern hemisphere influenza season
Neuraminidase reagents in use
Neuraminidase reagents
|
NIBSC code
|
|
N1
|
|
|
NA antiserum prepared from A/California/7/2009
|
10/218
|
|
NA antiserum prepared from A/New Caledonia/20/99
|
04/230
|
|
NA antiserum prepared from A/Victoria/4897/2022
|
23/208
|
|
N2
|
|
NA antiserum prepared from A/Victoria/361/2011
|
14/144
|
|
NA antiserum prepared from A/South Australia/34/2019
|
19/320
|
|
B
|
|
NA antiserum prepared from B/Jiangsu/10/2003
|
04/228
|
|
NA antiserum prepared from B/Malaysia/2506/2004
|
05/252
|
|
NA antiserum prepared from B/Phuket/3073/2013
|
21/322
|
Candidate influenza viruses for use in the northern hemisphere 2025-262
Candidate influenza vaccine viruses
|
NIBSC code
|
|
H1N1
|
|
|
A/Victoria/4897/2022
|
23/252
|
|
IVR-238 reassortant derived from A/Victoria/4897/2022
|
23/250
|
|
A/West Virginia/30/2022
|
23/122
|
|
A/Wisconsin/67/2022
|
23/120
|
|
A/Norway/31694/2022
|
22/312
|
|
NIB-133 reassortant derived from A/Norway/31694/2022
|
23/112
|
|
NIB-134 reassortant derived from A/Catalonia/NSVH161512065/2022
|
23/126
|
|
CNIC-2301 reassortant derived from A/Sichuan-Qingyang/SWL1148/2023
|
23/214
|
|
H3N2
|
|
|
A/Croatia/10136RV/2023
|
25/230
|
|
NIB-146 reassortant derived from A/Croatia/10136RV/2023
|
24/158
|
|
NYMCX-425A reassortant derived from A/Croatia/10136RV/2023
|
24/162
|
|
A/District of Columbia/27/2023
|
24/166
|
|
B (Victoria lineage)
|
|
|
B/Austria/1359417/2021 (BVR-26) antigen
|
24/180
|
|
B/Michigan/01/2021 antigen
|
21/330
|
|
B/Singapore/WUH4618/2021 (cell derived) antigen
|
23/268
|
|
B/Austria/1359417/2021 - like antiserum
|
24/118
|
|
B (Yamagata lineage)
|
|
|
B/Phuket/3073/2013 antigen
|
21/136
24/182
|
|
B/Utah/9/2014 (cell derived) antigen
|
15/100
|
|
B/Singapore/INFTT-16-0610/2016 (cell derived) antigen
|
19/308
|
|
B/Phuket/3073/2013 - like antiserum
|
22/132
|
2Recommended composition of influenza virus vaccines for use in the 2025-2026 northern hemisphere influenza season
Access To B/Yamagata lineage viruses is currently restricted.
Please contact Othmar.Engelhardt@mhra.gov.uk and Jason.Long@mhra.gov.uk
SRD reagents for use in the northern hemisphere 2025-262
(For B Victoria and B Yamagata lineage reagents please see tables for southern hemisphere 2026 above)
Reagents for influenza vaccine standardisation
|
NIBSC code
|
|
H1N1
|
|
|
A/Victoria/4897/2022 (IVR-238) antigen
|
22/320
|
|
A/Georgia/12/2022 (CVR-167) (cell derived) antigen
|
24/198
|
|
A/Victoria/4897/2022 - like antiserum
|
23/278
|
|
H3N2
|
|
|
A/Croatia/10136RV/2023 (NYMC X-425A) antigen
|
24/174
|
|
A/Croatia/10136RV/2023– like antiserum
|
24/176
|
2Recommended composition of influenza virus vaccines for use in the 2025-2026 northern hemisphere influenza season
Pricing information
Viruses are free of charge (normally a maximum of two vials per recipient), but customers are expected to pay shipping and packing costs. Reagents for Single Radial Diffusion assay are subject to a handling fee as stated on the product information page, plus shipping and packing costs. Approved National Control Laboratories for human health are exempt from the handling fee.
Calibration of Reagents for Influenza vaccine standardisation
Reference antigens and antiserum reagents for the standardization of vaccines are produced by the following WHO laboratories:
Essential Regulatory Laboratories (ERL)
- Medicines and Healthcare products Regulatory Agency (MHRA), UK
- Center for Biologics Evaluation and Research (CBER), USA
- National Institute for Infectious Disease (NIID), Japan
- Therapeutic Goods Administration (TGA), Australia