According to the NHS the current flu vaccine cocktail covers the following:-
Most injected flu vaccines protect against 3 types of flu virus:
A/H1N1 – the strain of flu that caused the swine flu pandemic in 2009
A/H3N2 – a strain of flu that mainly affects the elderly and people with risk factors like a long-term health condition. In 2017/18 the vaccine will contain an A/Hong Kong/4801/2014 H3N2-like virus
Influenza B – a strain of flu that particularly affects children. In 2017/18 the vaccine will contain B/Brisbane/60/2008-like virus
The nasal spray flu vaccine and some injected vaccines also offer protection against a fourth B strain of virus, which in 2017/18 is the B/Phuket/3073/2013-like virus.
