No vaccination is mandatory for your trip to Vietnam but we would like to give you some recommendations regarding vaccines. This list is recommended by the Pasteur Institute.

Japanese encephalitis
From the age of 2 months for expatriates or to stay in rural areas during the transmission period, 2 injections over a period of 7 to 28 days (adults 18-65 years), booster 12 to 24 months later.

Hepatitis B
For long or frequent stays: 2 injections spaced out for a month, single booster 6 months later. When immunity must be acquired quickly (in case of imminent departure), an accelerated regimen of three doses spaced at D0, D7, D21 and a fourth dose administered 1 year later can be used only in adults.

Rage
In case of prolonged stay in isolation (children, as soon as they walk): three injections on D0, D7, D28 (or 21)

Typhoid
In case of prolonged stay or in precarious hygiene conditions (children, from the age of 2 years); an injection 15 days before departure.

Malaria
Year-round transmission in the highlands below 1500m south of latitude 18° N. No transmission in urban centers of the country.

Covid 19
All tourists can enter Cambodia without vaccination, but still require a rapid test upon arrival at the airport with the extra cost of 5$ per person (pay on spot).In case of a negative test result: the travelers are allowed to continue their journey to their destination throughout Cambodia without quarantine. In case of a positive test result and mild disease: must be treated in accordance with Standard Operating Procedures for Management, Care, and Treatment of Covid-19 Patents at Home.
In case of serious disease: he/she has to receive COVID-19 treatment at the hospital, and they have to pay for their own medical treatment and accommodation. 
If travelers have been two times vaccinated, a rapid test is not required.