We have great dr's on island if for any reason you need an antibiotic. Don't bring an antibiotic unless it's been prescribed for a specific ailment...there is too much antibiotic resistant bacteria in the World right now, don't use one unless it's needed. Our water is safe to drink/brush teeth etc. It's from a desalination plant...no problems there. Tetnus shots are a good shot to stay up to date with even at home...but we can do that here if for any reason you needed one. I haven't had a Hep A vaccine since I went to Africa 17 years ago...again, not very necessary that I know of.
We have just had a lot of rain in a short period of time, which tends to produce some mosquitoes over the next 2 weeks (hotels spray, but you could get bitten at dawn and dusk). It's not bad, but if you are sensitive to biting insects and are arriving in the next couple of weeks, bring some Off from home...it's more expensive here. (Again they won't be bad compared to rainforest type places, but just more than we're used to.
Hope that helps...