Hepatitis A is very contagious. I had it as a child and was isolated in the hospital for a month or so. I was also kept away from my siblings when I returned home, for a period of time. They now, as an adult have checked me for A, B, and C . I do not have any of them and am now immune to Hep. A. But it did do substancial damage to my liver.
That is my experience. There was not a required vaccine when I was young.
is Hapatitis A contagious