The periodic replacement of virus strains contained in influenza vaccine is necessary because of the constant evolution of influenza viruses, which can change their antigenic and genetic characteristics. The World Health Organization (WHO) recommends the following influenza vaccine composition information.

Northern Hemisphere 2017-2018

WHO recommends that trivalent vaccines for use in the 2017-2018 northern hemisphere influenza season contain the following:
•    an A/Michigan/45/2015 (H1N1)pdm09-like virus;
•    an A/Hong Kong/4801/2014 (H3N2)-like virus; and
•    a 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.

More Information

WHO. (March 2017) Recommended composition of influenza virus vaccines for use in the 2017-2018 northern hemisphere influenza season.

WHO. (March 2017) Questions and Answers. Recommended composition of influenza virus vaccines for use in the Northern hemisphere 2017 - 2018 influenza season and development of candidate vaccine viruses for pandemic preparedness.

Southern Hemisphere 2017

WHO recommends that trivalent vaccines for use in the 2017 southern hemisphere influenza season contain the following:
•    an A/Michigan/45/2015 (H1N1)pdm09-like virus;
•    an A/Hong Kong/4801/2014 (H3N2)-like virus; and
•    a 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.

More Information

WHO. (September 2016) Recommended composition of influenza virus vaccines for use in the 2017 southern hemisphere influenza season. Full Report.

WHO. (September 2016) Questions and Answers. Recommended composition of influenza virus vaccines for use in the southern hemisphere 2017 influenza season and development of candidate vaccine viruses for pandemic preparedness.

 

(Updated 3 March 2017)