He's ok now,he's only now due to have an outpatient procedure requiring a night in hospital. He was in hospital for 7 nights with various tests,treatments and procedures being done. I'm OK now, not so when I got the message of hospitalisation!
We provided boarding passes for all trips I took to the US and within the US together, letters/emails,communications from start of knowing each other up until the last date I-130 package was mailed.(we're a large age gap couple) so didn't want any doubts! I being younger than him.
As you have lived together, get leases,financial info &bills showing you lived together and any birth certificates if you have children together.
The one vaccine I'm aware of that the UK doesn't do is the Varicella, but it's offered at your medical.
Best of luck.