Dr. Johnson: Here the principal of “do no harm” applies. In general, live vaccines have some potential for infecting the baby if given during pregnancy. Although serious harmful effects have not been well documented in babies of mothers who have received live vaccines during pregnancy, subclinical infections have been documented and for this reason live vaccines should be avoided. Furthermore, even though the quadrivalent HPV vaccine does not contain live virus, its use in pregnancy is not recommended. The measles, mumps and rubella vaccines are contraindicated during pregnancy as mentioned above. Finally, the varicella vaccine is also a live virus vaccine and should not be given to women who are currently pregnant. (From ACIP guidelines).