This question would probably be a better fit for law.stackexchange.com. With that said, I'll try to answer it from the legal perspective.
Firstly, guidance is not law. Guidance is instead usually (a) a summary of what the author of the guidance considered to be the law at the time of writing, and/or (b) a collection of recommendations which are not legally ...
Is visiting your grandmother right now even a good idea?
The UK is currently a major Covid hotspot, with a virulent new strain emerging there. Visiting a critically ill, elderly person right before a major surgery seems like a very bad idea to me. She's already a member of the most at-risk group in society of dying or suffering serious complications from ...
Your need to see a person before a surgery, or to bring some people to see that person, is not a medical emergency. Her need for the surgery, may be, but it is not her who wants to travel. I doubt you will get an exception.
Where you might have a chance is, it says on your link that you can travel for the same reasons you can leave home, and you can leave ...
Adding an answer based on IATA's COVID travel page. You can find the full text of the exemption on the IATA page, only adding the country names here for brevity.
Anyone in the world can go
Georgia. See the official government website of Georgia for additional reference.
Seychelles (not mentioned on IATA, so referencing their ...
thepointsguy.com provides a list of countries that have a vaccination passport, as well as details for each country as to what the vaccination passport allows: