Just washing your hands or using an alcohol cleaning fluid (Minimum 60% ethanol) can be surprisingly effective. This is because you are constantly touching your face without realising it which helps transfer the virus from the many surfaces you touch to points of entry to your body.
If you are going to a region effective getting into the good habit of regularly washing your hands may be a good idea.
As might taking vitamin C and Zinc supplements which have some limited evidence to indicate it helps your immune system,