She is so good at playing bad girls that complete strangers have walked up to Claire King and berated her.

She has even been hit over the head with a brolly “for being awful to Frank”, her Emmerdale husband at the time.

The actress who gave life to the soap’s arch villain, Kim Tate, Bad Girls’ feisty governor Karen Betts and Corrie’s man-eating Erica Holroyd says: “It’s much more fun to play a villain than a downtrodden doormat but thank goodness they are only characters. I am not really that hard, honestly.”

In fact in the real world one of her most demanding roles could not be further from the uncaring Kim Tate. 

Along with her brother, Piers, Claire helps to care for her 77-year-old parents, dad John, who has multiple sclerosis, and mum Angela who suffers with both osteoarthritis and rheumatoid arthritis.

Both need around-the-clock support and are so dependent on hoists and other specialist equipment that their home even has a back-up generator in case of power cuts.

“It’s an expensive business,” says Claire, a long-time campaigner for Britain’s army of unpaid carers.

“They estimate that when someone is disabled, the household spends £35,000 more than the average and the support families get only goes so far – that’s why I’ll be working until I’m 90,” she jokes. 

But Claire, 54, is quick to acknowledge that, unlike many families, she and her brother are fortunate to be able to pay for full-time care.

There are around seven million carers in the UK, that’s one in 10 of us.

A recent report found that a quarter have not taken a day off in five years and three out of five report their own health has suffered as a result of caring.

“That’s precisely why I’m encouraging other carers to think about themselves as well as the people they care for and get their free flu vaccination this winter,” says Claire.

Ideally you should have the jab in early autumn so you’re protected by the time viruses peak but as Claire points out: “It’s better late than never. Last winter only 42 per cent of carers had a flu vaccination but I know that if I, or any of my parents’ other carers were struck down by flu they would be lost.” 

With the emergence of deadly Aussie flu and warnings from the Royal College of Emergency Medicine that NHS services are dangerously overstretched, experts fear this could be the worst winter for infections since the Hong Kong flu epidemic in 1968.

And while there are concerns that jabs may not offer the same levels of protection seen in previous years, high-risk groups are being urged to take advantage of free vaccinations.

As well as carers, anyone over 65, pregnant women, children and adults with weakened immunity, and those with some medical conditions such as diabetes or respiratory disease are eligible for a free flu jab.

For Claire vaccination is doubly important as she is not only a carer but, like her mother, she has also been diagnosed with rheumatoid arthritis.

Unlike osteoarthritis, which is associated with wear-and-tear and strikes later in life, rheumatoid arthritis occurs when the immune system goes into overdrive and attacks tissue cushioning the joints.

It affects more than 400,000 people in the UK and can strike at any age. Claire was in her 30s, and had just joined the cast of Emmerdale when she was diagnosed and at the time she feared it would put an end to her career.

“I had visions of ending up in a wheelchair,” she says, and the reality is that one in three are forced to stop working within 24 months of the first signs. Her condition is kept in check with a cocktail of anti-inflammatory medicines including hydroxychloroquine sulphate and methotrexate, which work by suppressing the immune system. 

“That’s why I know the flu vaccination works. Having low immunity, I pick up bugs left, right and centre. But I’ve had a jab the past 10 or 12 years and I have never had flu in that time,” she says.

“I am lucky I can manage my arthritis. But you can get flare-ups and I’ve learnt to avoid certain foods or drinks. I try to do some exercise, I eat fresh veg and cook from scratch and I don’t do a lot of takeaways or ‘ping’ meals.”

Claire is also convinced that some supplements help and regularly takes MSM, turmeric and omega-3 for her joints as well as vitamin D to support her immune system.

“I do rattle a bit,” she jokes. She still worries about what the future may hold and while she is essentially an optimist, the unpredictable nature of rheumatoid arthritis and her parents’ struggle with disability mean she does not shy away from uncomfortable conversations.

“We’re pretty open as a family and we discuss death and funerals because we’ve had illness throughout my whole life.” 

Since leaving Corrie, Claire has been filming a four-part show for ITV in Sardinia.

“It’s very interesting. I can’t say too much but it’s quite an experiment and very funny,” she teases.

There’s also a film, called Milk And Honey due out next year. “For a woman of my age in this business, I am doing all right – I’m still here,” she says, although she adds that men of her age have a much greater range of roles.

“The parts they do have for women my age are very good but they are few and far between.”

● Free NHS vaccinations are available for carers and other “at risk” groups until February and with more than 2,000 Boots stores offering vaccinations you don’t even need to visit your GP for a jab.