The need for adults to be vaccinated against hepatitis A depends on the nature of their work. If you eat out a lot, you can get vaccinated. The hepatitis A virus is transmitted through the fecal-oral transmission, that is, through the digestive tract. The saliva of a hepatitis A patient contains the virus, so if you have a dinner party with friends, it is very easy to spread the hepatitis A virus because people do not have the habit of using common spoons and chopsticks. If a hepatitis A patient’s hands are not washed clean and contaminate door handles, handrails on buses, etc., healthy people can easily get infected with hepatitis A after touching these parts. It is common for aquatic animals to carry the hepatitis A virus, such as snails, shells, arks, crabs, and so on. Adults who like to eat semi-raw or undercooked seafood are very susceptible to hepatitis A infection after eating these aquatic products. It is because the hepatitis A virus is easier to come into contact with in daily life that it is best for adults to be vaccinated against hepatitis A.