• If your child is allergic (hypersensitive) to any of the components of ProQuad (including neomycin or any of the ingredients listed under “ other ingredients” -see section 6, Further information). • If your child has a blood disorder or any type of cancer that affects the immune system. • If your child is receiving treatment or taking medications that may weaken the immune system (except low-dose corticosteroid therapy for asthma or replacement therapy). • If your child has a weakened immune system because of a disease (including AIDS). • If your child has a family history of congenital or hereditary immunodeficiency, unless the immune competence of your child is demonstrated. • If your child has active untreated tuberculosis. • If your child has any illness with fever higher than 38.5°C; however, low-grade fever itself is not a reason to delay vaccination. • If your child is pregnant (in addition, pregnancy should be avoided for 3 months after vaccination, see Pregnancy and breast-feeding).