In a report published today by the World Health Organization (WHO), officials outlined their recommendations for the composition of the influenza vaccine for the 2017-2018 northern hemisphere flu season. Here is an excerpt:
Influenza A(H3N2) viruses predominated in most countries, with low levels of A(H1N1)pdm09 and influenza B viruses also circulating during the period September 2016 – February 2017.
Influenza A(H1N1)pdm09 viruses were antigenically indistinguishable by post-infection ferret antisera raised against current vaccine viruses A/California/7/2009 and A/Michigan/45/2015. However, representative circulating viruses were poorly inhibited by some post-vaccination adult human serum pools.
Influenza A(H3N2) viruses were associated with outbreaks in many countries. The majority of recent viruses were antigenically related to cell culture-propagated 3C.2a A/Hong Kong/4801/2014-like viruses. A(H3N2) viruses within the 3C.2a clade have become genetically diverse, although they remain antigenically similar. The majority of recently circulating A(H3N2) viruses belong to subclade 3C.2a1.
Influenza B viruses of the B/Victoria/2/87 and the B/Yamagata/16/88 lineages co-circulated at similar levels in some regions, but in many countries in South America, Asia and Eastern Europe, B/Victoria/2/87 lineage viruses were predominant. Most B/Victoria/2/87 lineage viruses were antigenically and genetically closely related to B/Brisbane/60/2008 and B/Texas/2/2013. The majority of recent B/Yamagata/16/88 lineage viruses were antigenically and genetically closely related to B/Phuket/3073/2013.
It is recommended 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.
Read the full report HERE