3 ms·And remember Hep B is 2 shots several months apart.by Gustomaximus 9y agoAnd remember Hep B is 2 shots several months apart.tallanvor 9y ago4 shots. The first 3 given in one month intervals, and the 4th a year later.Animats 9y agoThen you're done for maybe 25 years. At one time, the US did mass inoculations in schools, using air injectors. Just lined everybody up and zapped them.