ANDERS Gibson knows only too well the unpredictable nature of flu.
As a sufferer of cystic fibrosis, which affects the internal organs, especially the lungs, by clogging them with thick, sticky mucus, the 34-year-old from Glasgow makes sure he gets vaccinated against the illness every year.
But after having the jab last winter, he caught a different strain of the virus and spent a month in hospital.
He said: "It was a different variation of flu that I managed to pick up in April. I had acute kidney failure as a result of that and was in hospital for a whole month. I have not quite been the same since.
"The symptoms were that I just felt quite tired and my breathing wasn't great, but when you have respiratory problems sometimes you just think you're having a bad day.
"I'd actually had it for perhaps a few days before I got to hospital. I didn't have a temperature either, which was a bit strange.
"It was more just breathlessness and being really tired, really lethargic. By the time I got to hospital, I was struggling just to make it a few feet in terms of walking, but I hadn't realised how bad I was because I had been lying in bed."
He added: "I couldn't take antibiotics at the time as my kidneys had gone into failure, so the doctors had to wait for them to recover before they could actually give me anything to help my chest.
"There was nothing they could do apart from give me oxygen and fluids, as I was dehydrated."
Gibson, who is hoping to be placed on the waiting list for a lung transplant soon, is urging others with chronic health conditions to make sure they have the "quick and painless" flu vaccine.
He said: "Now that I am approaching the opportunity of a lung transplant, it is essential that I get it – flu could be the last thing that my lungs could take really.
"With my lung function being so low, I know that any kind of flu could leave me very unwell and really threaten my life.
"The seasonal flu jab is a preventative measure that I would not do without. I would definitely recommend that other people with chronic illness visit their GP to get the jab. It's not worth taking the risk."