Based on clinical evidence new guidance on the vaccines to be used in the 18/19 season was published on 5th February 2018^b.

The following vaccines should be offered to individuals eligible for an NHS vaccination:

• Adjuvanted trivalent influenza vaccine (aTIV) (Fluad)  -  65 years and over
• Quadrivalent influenza vaccine (QIV) -  18 to under 65 years in "at risk" groups

As recommened by the World Health Organisation^c the composition of the vaccines for the northern hemisphere contain the following:

1. an A/Michigan/45/2015 (H1N1)pdm09-like virus
2. an A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus
3. a B/Colorado/06/2017-like virus (B/Victoria/2/87 lineage) 
4. For the quadrivalent - a B/Phuket/3073/2013-like virus (B/Yamagata/16/88 lineage)

^b https://psnc.org.uk/wp-content/uploads/2018/02/07648-Vaccine-ordering-for-2018-19-influenza-season-GPpharm-05022018.docx.pdf

^c http://www.who.int/influenza/vaccines/virus/recommendations/2018_19_north/en/