Japanese B Encephalitis
The vaccine is recommended for travellers planning extended trips to affected rural areas, e.g. rice fields and marshland. This is usually defined as in excess of 30 days. For an area with active epidemic Japanese encephalitis, vaccination should be considered for shorter stays.
Vaccination, even for short stays, is recommended if the person expects unprotected nocturnal outdoor exposure in an endemic area.
As with malaria, prophylaxis must be supplemented by techniques to avoid being bitten by mosquitoes.