My son has taken two bcg.does it has harmful effects on him?

BCG: Why is somebody in usa taking bcg? Only recommended for areas with high rates of TB exposure. As long as your son is not immunosuppressed, and has no residual symptoms the two doses should not be a problem. Infection with this bacillus is inordinately rare. If he develops any symptoms take him back to doctor asap, but suspect you have nothing to worry about.