Does anyone have feedback on Sambucol? US version vs UK version?

I've been giving my children sambucol to boost their immune system when they started going to childcare because they get sick every month. I've seen improvement in them. Most importantly, they like the taste of sambucol and it's not a chore to feed them. Sambucol UK version for 1 year old and above US version for 2 years old and above (slightly sweeter)