Food and drink:

Mains water is safe to drink but some visitors do get mild abdominal upsets. There is high calcium content in the water, which can result in a few white specks in tea or coffee. Bottled water is inexpensive and readily available. It is important to keep well-hydrated in the tropics. Most milk is UHT/long life milk. Local meat, poultry, seafood, fruit and vegetables are considered safe to eat. The local beef (organic) is excellent.

Other risks: 

While there have been no recorded cases of malaria on the main island of Efate for many years, for travel to some of the outer islands, anti-malaria medication is recommended. Consult your doctor/physician. Your doctor may also recommend a vaccination against hepatitis. A tetanus injection can be required for some cuts/abrasions but this can be had after the event. Coral cuts are common and they can become infected. Treat with hydrogen peroxide, antiseptic and keep covered.