Flu Vaccine Changes Confirmed for 2021-2022

The World Health Organization (WHO) announced that the influenza vaccine selection committee finalized its recommendations for the Northern Hemisphere's 2021-22 flu season.

These recommendations were made within the context of the ongoing COVID-19 pandemic. Overall, record-low levels of influenza detections were reported, and fewer viruses were available for characterization during September 2020 to January 2021 time period than in previous years, said the WHO.

Globally, since September 2020, influenza activity was mostly reported from countries in the tropics and subtropics and some countries in the temperate zone of the Northern Hemisphere.

Overall, the percent positivity for influenza viruses in all specimens tested was less than 0.2% during this period. In contrast, the average percent positivity during the same reporting period of the three previous seasons (2017-2020) was 17%.

On February 26, 2021, the WHO recommended that quadrivalent vaccines for use in the 2021 - 2022 northern hemisphere influenza season contain the following:

Egg-based Vaccines:

• 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
• a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus

Cell- or recombinant-based Vaccines:

• 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
• a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus

It is recommended that trivalent influenza vaccines for use in the 2021 - 2022 Northern Hemisphere influenza season contain the following:

Egg-based Vaccines:

• 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

Cell- or recombinant-based Vaccines

• 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

Compared with the Southern Hemisphere recommendation made in September 2020, the H3N2 recommendations were changed for the egg and other versions.

The WHO published updated FAQs, which are found on this WHO page.  

The current flu vaccine recommendations from the U.S. CDC can be found on this webpage.  

PrecisionVaccinations publishes research-based vaccine news.