Watch: Ian McKellen's 'euphoric' response after getting the COVID-19 vaccine

Sir Ian McKellen was all (masked) smiles and thumbs up as he received his first dose of the Pfizer COVID-19 vaccine. 

The Lord of the Rings star performed an ecstatic elbow bump with the NHS worker who administered the jab, saying he felt "euphoric" and "lucky" to have access to the immunisation. 

"It's a very special day, I feel euphoric. I would have no hesitation in recommending it to anyone. I feel very lucky to have had the vaccine," he said. 

Asked about the NHS staff, Sir Ian said "he'd like to give them all a big hug" - as long as that didn't break any COVID-19 restrictions.  

"Next time I come, well no, six days after I next come I'm going to give them all a big hug - is that allowed? I don't know."

"That's the real bonus of all this, to watch and see what works in this country and what doesn't work - and it seems to me the NHS is right at the top of the list for institutions that do work," the acting stalwart added. 

"Of course, I know I wouldn't be alive if it wasn't for the NHS. I'm a little bit older than the NHS but when I was a kid, having good medical treatment available when it was needed - what a wonderful notion." 

Sir Ian, best known for his role as wizard Gandalf, encouraged the public to "do the sensible thing" and get the shot "not just for themselves but for everybody else". 

"Because if you're virus-free that helps everybody else, doesn't it?"

"It is invasive of course," Sir Ian added. "It looks like a weapon - a needle - but it isn't, it's a friend!"

Fans of Sir Ian shared the video of his treatment on Twitter and couldn't help using one of the 81-year-old actor's most iconic quotes. 

"SARS CoV 2 getting the 'You shall not pass!" treatment from Gandalf," one Twitter user wrote, along with a Lord of the Rings GIF. 

"YOU SHALL NOT PASS... your infection on to me," wrote another. 

The UK began its rollout of the Pfizer vaccine last week, prioritising patients over the age of 80 for the first stage of the immunisation programme.