There are THREE primary flu vaccinations before annual boosters:
1st – Primary Vaccination must be given
2nd – Primary Vaccination between 21 and 92 days after 1st primary vaccination
3rd – Primary Vaccination between 150 and 215 days after 2nd primary vaccination
Further booster vaccinations at intervals of not more than a year apart (or such lesser time as the Authority may, in an emergency, decide)

REMEMBER - The first two vaccinations must be given BEFORE a horse can be taken to a racetrack
REMEMBER - None of the vaccinations must have been given on the day of a race in which the horse is declared to run or on any of the six days before the race
REMEMBER - to COMPLETE the programme by having the third vaccination – the time for this could well be in Autumn after the horse has been turned out for winter
REMEMBER – The current Owner/Trainer of the horse is responsible for ensuring the FLU VAC RECORD is correct NOT the BHRC

MARCH 2019 UPDATE:
As many will be aware, since the start of 2019 a number of equine influenza cases have been identified across Europe and the UK, including several in vaccinated horses.

The BHRC have reviewed advice on this and the following is recommended by the BHRC:

• ALL horses are vaccinated with Florida Clade 1 and Florida Clade 2 protection – see AHT advice on UK vaccines HERE
• ALL horses that have not received a booster or vaccination within the last six months should be issued a booster as soon as possible

All owners and trainers are advised to be extra-vigilant, with ongoing extra care in regard of biosecurity and the isolation of new horses entering training stables.
Any horses showing signs that could be flu (especially harsh dry cough) should be isolated and promptly investigated by your vet.

Any cases positive for equine influenza must be reported to the BHRC immediately:
W58. Any person holding a Trainer’s licence shall immediately notify the Secretary of the BHRC of any infectious or contagious disease in his stables. Failure may result in closure of premises.