HARRISON Kershaw was a happy youngster, and like many boys, loved nothing more than a game of football.

But that was before he developed a rare sleeping disorder — after a swine flu jab three years ago.

Harrison, now aged eight, has narcolepsy and cataplexy, meaning he can collapse into sleep up to seven times a day.

His mother, Leanne, says he is now ‘unrecognisable’ to the son she knew before the injection.

Leanne, from Farnworth, said: “A month after he was given the injection I noticed he started to sleep a lot more in the day, and when he was overcome with emotion his muscles would flop.

“Now he has doubled in weight and is unrecognisable to before he had the vaccine.”

Harrison now has to have two planned naps a day at school, and his parents, Leanne and Simon, have to take a wheelchair with them in case he falls asleep and collapses.

The Cherry Tree Primary School pupil’s behaviour has also been severely affected by the condition.

“When someone with narcolepsy wakes up, it can feel like they’ve not slept for more than 72 hours.

“This means Harrison’s behaviour can be very challenging because he feels exhausted and can be very grumpy,” said the mum-of-three.

“Normal sleep just doesn’t keep him going and if he misses anything at school, he will never be able to catch up. Even though he is on medication to keep him awake, he still feels constantly tired.

“If we are in the car he will fall asleep, and sometimes he will fall asleep while he’s eating, which means we have to make sure he doesn’t choke.

“It can be hard to deal with but it’s not his fault. He can’t help the way he behaves.

Harrison’s narcolepsy meant he had to stop playing at his football team and now plays for a disability team.

Leanne has since met with the parents of 18 other children who developed narcolepsy after having the flu jab.

Law firm Hodge Jones & Allen have now started legal action against Pandemrix manufacturers GlaxoSmithKline on behalf of Harrison and 37 other Britons.

A spokesman for GlaxoSmithKline said: “Patient safety is our number one priority and we are actively researching how narcolepsy is triggered and how this vaccine might have interacted with other risk factors in affected individuals.

“We hope these ongoing research efforts will enable us to provide more answers.”

Leanne is also supporting a fundraiser to raise cash for Sleeping Beautyz Trust, which was set up in aid of children like Harrison, who suffer from narcolepsy and cataplexy.

The event will take place from noon on Sunday at St Gregory’s Social Club in Farnworth.

Entry is £2 for adults, £1 for children and all under-10s will receive a free present from Santa.