2025-2026 Influenza Vaccine Composition (Click the WHO link for more info)

WHO recommends that trivalent vaccines for use in the 2025–2026 northern hemisphere influenza season contain the following:

The egg based trivalent vaccines for use in the 2025-2026:

• an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
• an A/Croatia/10136RV/2023(H3N2)-like virus;
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

Cell- or recombinant-based quadrivalent vaccines for use in the 2025-2026:

• an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
• an A/District of Columbia/27/2023(H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.
  

It is recommended that all 2024-2025 U.S. flu vaccines be three-component (trivalent) vaccines and include an influenza A(H1N1), an A(H3N2) and a B/Victoria-lineage vaccine virus. Influenza B/Yamagata viruses are no need to be included.

The egg based trivalent vaccines for use in the 2024-2025 northern hemisphere influenze season contain the following:

• an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
• an A/Thailand/8/2022 (H3N2)-like virus;
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.

Cell- or recombinant-based quadrivalent vaccines for use in the 2024-2025:

• an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
• an A/Massachusetts/18/2022 (H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus.
  

2023-2024 Influenza Vaccine Composition

It is recommended that egg based quadrivalent vaccines for use in the 2023-2024 northern hemisphere influenza season contain the following:

• an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
• an A/Darwin/9/2021 (H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata/16/88 lineage)-like virus.

Cell- or recombinant-based quadrivalent vaccines for use in the 2023-2024:

• an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
• an A/Darwin/6/2021 (H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata/16/88 lineage)-like virus.

2022-2023 Influenza Vaccine Composition

It is recommended that egg based quadrivalent vaccines for use in the 2022-2023 northern hemisphere influenza season contain the following:

• an A/Victoria/2570/2019 (H1N1)pdm09-like virus;
• an A/Darwin/9/2021 (H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata/16/88 lineage)-like virus.

Cell- or recombinant-based quadrivalent vaccines for use in the 2022-2023:

• an A/Wisconsin/588/2019 (H1N1)pdm09-like virus;
• an A/Darwin/6/2021 (H3N2)-like virus; 
• a B/Austria/1359417/2021 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata/16/88 lineage)-like virus.

2021-2022 Influenza Vaccine Composition

It is recommended that egg based quadrivalent vaccines for use in the 2021-2022 northern hemisphere influenza season contain the following:

• an A/Victoria/2570/2019 (H1N1)pdm09-like virus;
• an A/Cambodia/e0826360/2020 (H3N2)-like virus; 
• a B/Washington/02/2019 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata/16/88 lineage)-like virus.

Cell- or recombinant-based quadrivalent vaccines for use in the 2021-2022:

• an A/Wisconsin/588/2019 (H1N1)pdm09-like virus;
• an A/Cambodia/e0826360/2020 (H3N2)-like virus; 
• a B/Washington/02/2019 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013 (B/Yamagata/16/88 lineage)-like virus.

2020-2021 Influenza Vaccine Composition

It is recommended that egg based quadrivalent vaccines for use in the 2020-2021 northern hemisphere influenza season contain the following:

• an A/Guangdong-Maonan/SWL1536/2019 (H1N1)pdm09-like virus;
• an A/Hong Kong/2671/2019 (H3N2)-like virus; 
• a B/Washington/02/2019 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).

Cell- or recombinant-based quadrivalent vaccines for use in the 2020-2021:

• an A/Hawaii/70/2019 (H1N1)pdm09-like virus;
• an A/Hong Kong/45/2019 (H3N2)-like virus; 
• a B/Washington/02/2019 (B/Victoria lineage)-like virus; and
• a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).

2019-2020 Influenza Vaccine Composition

It is recommended that egg based quadrivalent vaccines for use in the 2019-2020 northern hemisphere influenza season contain the following:

• an A/Brisbane/02/2018 (H1N1)pdm09-like virus;
• an A/Kansas/14/2017 (H3N2)-like virus; 
• a B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage); and
• a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage).

It is recommended that the influenza B virus component of trivalent vaccines for use in the 2019-2020 northern hemisphere influenza season be a B/Colorado/06/2017-like virus of the B/Victoria/2/87-lineage.

2018-2019 Influenza Vaccine Composition

It is recommended by WHO that quadrivalent vaccines for use in the 2018-2019 northern hemisphere influenza season contain the following:

• A/Michigan/45/2015 (H1N1)pdm09–like virus;
• A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus;
• B/Colorado/06/2017-like virus(B/Victoria/2/87 lineage); and
• B/Phuket/3073/2013-like virus (Yamagata lineage)

It is recommended that the influenza B virus component of trivalent vaccines for use in the 2018-2019 northern hemisphere influenza season be a B/Colorado/06/2017-like virus of the B/Victoria/2/87-lineage.

2017-2018 Influenza Vaccine Composition

All 2017-18 influenza vaccines licensed in the United States will contain hemagglutinin (HA) derived from influenza viruses antigenically similar to those recommended by FDA.

2017–18 trivalent vaccines:

• A/Michigan/45/2015 (H1N1)pdm09–like virus;
• A/Hong Kong/4801/2014 (H3N2)-like virus; 
• B/Brisbane/60/2008-like virus (Victoria lineage)

2017–18 quadrivalent vaccines:

• the same three HA antigens as trivalent vaccines, plus
• B/Phuket/3073/2013-like virus (Yamagata lineage)

2016-2017 Influenza Vaccine Composition

It is recommended that trivalent vaccines for use in the 2016-2017 influenza season (northern hemisphere winter) contain the following:

• A/California/7/2009 (H1N1)pdm09-like virus;
• A/Hong Kong/4801/2014 (H3N2)-like virus;
• B/Brisbane/60/2008-like virus.

It is recommended that quadrivalent vaccines containing two influenza B viruses contain the above three viruses and a B/Phuket/3073/2013-like virus.

2015-2016 Influenza Vaccine Composition

It is recommended that trivalent vaccines for use in the 2015-2016 influenza season (northern hemisphere winter) contain the following:

• A/California/7/2009 (H1N1)pdm09-like virus;
• A/Switzerland/9715293/2013 (H3N2)-like virus;
• B/Phuket/3073/2013-like virus.

It is recommended that quadrivalent vaccines containing two influenza B viruses contain the above three viruses and a B/Brisbane/60/2008-like virus.

2014-2015 Influenza Vaccine Composition

The vaccine viruses recommended by WHO for the 2014-15 northern hemisphere influenza season are the same as those for the northern hemisphere 2013-14 influenza season and 2014 southern hemisphere season. 

The WHO Vaccine Composition Meeting for the 2014-2015 season was held February 17 -19, 2014 at WHO headquarters in Geneva, Switzerland. On February 20, the Meeting recommended that trivalent vaccines for use in the Northern Hemisphere 2014-15 influenza season contain the following:

• A/California/7/2009 (H1N1)pdm09-like virus;
• A/Texas/50/2012 (H3N2)-like virus;
• B/Massachusetts/2/2012-like virus.

The Meeting also recommended that Quadri-valent Vaccines containing two influenza B viruses contain the above three viruses and a B/Brisbane/60/2008-like virus.

2013-2014 Influenza Vaccine Composition

It is recommended that trivalent vaccines for use in the 2013-2014 northern hemisphere influenza season contain the following:

• A/California/7/2009 (H1N1)pdm09-like virus;
• A/Victoria/361/2011 (H3N2)
• B/Massachusetts/2/2012
• B/Brisbane/60/2008

2012-2013 Influenza Vaccine Composition

It is recommended that trivalent vaccines for use in the 2012-2013 northern hemisphere influenza season contain the following:

• A/California/7/2009 (H1N1)pdm09-like virus;
• A/Victoria/361/2011 (H3N2)-like virus
• B/Wisconsin/1/2010-like virus (from the B/Yamagata lineage of viruses)

Source:
FDA's Influenza Virus Vaccine Composition and Lot Release Info;
CDC FluView - Weekly US Influenza Surveillance Report