Question: what vaccines cannot be given together?
Answer: Diluents are not interchangeable, except for the sterile water used in Merck's measles-mumps-rubella (MMR), measles-mumps-rubella-varicella (MMRV), varicella, and live zoster vaccines. No other diluent can be used for these vaccines, and these diluents must not be used to reconstitute any other lyophilized vaccine.