Three weeks ago, my 1-year-old daughter received her measles-mumps-rubella vaccine. Yesterday, she woke up with a low-grade fever (99.5 degrees), and the side of her face looks like a hamster with its cheek stuffed with seeds. Although my doctor’s office says that a mumps reaction to the MMR vaccine is extremely rare, they couldn’t answer the rest of my questions. Is my daughter actually contagious? And if so, what’s the period of contagion? She was at a sitter this weekend and with other children last week.
Your sitter and the other children are perfectly safe, and your daughter probably is, too. Mumps is the safest of the live viral vaccines. Nevertheless, inflammation or infection of the parotid gland – one of the salivary glands – is a rare complication known as parotitis.
Your daughter’s pediatrician should be able to tell by examining her if the parotid gland, rather than a lymph node, for example, is indeed responsible for her chipmunk appearance. Vaccinated children are not contagious to others. So if your daughter has parotid swelling from the mumps component of the measles-mumps-rubella vaccine, she can’t spread vaccine virus to other children.
Incidentally, other viruses can cause parotitis, including Coxsackie virus, the virus that causes “hand, foot and mouth” syndrome during the summer months.