It's largely the impact

[Maybo]

I don't understand the sentence structure of the underlined part.
I guess the meaning is that the impact is so large that makes NHS under such intense pressure.

"It's largely the impact of this new variant that means the NHS is under such intense pressure."
(Coronavirus: UK variant 'may be more deadly by James Gallagher)

 

[teechar]

I don't understand the sentence structure of the underlined part.

It's a cleft sentence.
https://dictionary.cambridge.org/gr...cleft-sentences-it-was-in-june-we-got-married
https://www.bbc.co.uk/worldservice/learningenglish/youmeus/learnit/learnitv149.shtml

I guess the meaning is that the impact is so large that [STRIKE]makes[/STRIKE] it puts the NHS under such intense pressure.

No. "largely" means "mainly".
The sentence means:
The main reason the NHS is under such pressure is the impact of the new strain.

 

[jutfrank]

It means that the new variant is one of the main reasons why the NHS is under intense pressure.

[cross-posted]

 

[Maybo]

Does "means" mean "result in" in that sentence?

 

[emsr2d2]

Does "means" mean "result in" in that sentence?

Loosely, yes. The new variant is one of the things that is resulting in the NHS being under such intense pressure. (Note the use of the continuous there.)