Amendments are sent to the legislatures of the  states by default. Only one amendment, the 21st, specified a  convention. In any case, passage by the legislature or convention  is by simple majority.
Yes, there is a MMRV VIS, as well as a MMR VIS and a Varicella VIS. The law requires that a Vaccine Information Statement (VIS) be given out whenever certain vaccinations are administered, including MMR, varicella or MMRV vaccines.hen the first dose of measles, mumps, rubella, and varicella vaccines is administered at ages 48 months and older, use of MMRV vaccine generally is preferred over separate injections of MMR and varicella vaccines.
Combined measles, mumps, and rubella vaccine (MMR by Merck) as well as combined measles and rubella vaccine (M-R-Vax by Merck) were licensed; the vaccine was developed by Maurice Hilleman and colleagues at Merck.