Hepatitis B is contagious: mainly through blood, semen and secretions in the infected person's skin or mucous membranes are infected. In addition, mother-to-child or father-to-child transmission is possible. The best way to prevent this is to get the Hepatitis B vaccine. It's best to wear a condom until you have antibodies. Kissing is usually not contagious. However, if both partners have mouth ulcers, the infection can be transmitted by kissing or eating, ****using toiletries. That is why family members should not use toothpaste or toothbrushes.