Is the MMR vaccine harmful to babies?

Dear Dr. Donya,

My nine-month-old daughter is due for her MMR vaccine for measles next week. However I am quite confused, as well as scared, because I have heard that a lot of things like autism may be related to this vaccine.

Please let me know what this vaccine is exactly. And please also inform me:

1. What are the immediate reactions or effects of this vaccine?

2. What precautions should be taken before and after this vaccine?

3. Will my baby get sick after getting this vaccine?

Please advise me and thank you for all your help and advice.

-- P

Dear reader,

I personally have never had any experience with adverse reactions to the MMR vaccine, or seen side effects like autism. There is much debate about this topic, but there has never been a decision to stop giving the vaccination. The vaccine is beneficial in preventing measles.

About your questions:

1. Reactions can include a fever of 39.4 degree Celsius or higher, which happens in 5 percent to 15 percent of cases, usually beginning seven to 12 days after the MMR vaccination.

The fever generally lasts for one to two days (and for as many as five days). Most people with the fever are asymptomatic.

Transient rashes have been reported in 5 percent of those receiving the vaccine. The reported frequency of central nervous system conditions, including encephalitis or encephalopathy, is less than one per million doses administered. Allergic reactions are usually minor, such as a wheal or urticaria (hive) at the injection site.

Reactions have been attributed to trace amounts of neomycin or gelatin, or some other component, in the vaccine formulation. Anaphylaxis is extremely rare. The measles vaccine is produced in a chicken embryo cell culture and doesn't contain significant amounts of cross-reacting proteins from eggs. Recent studies indicate that children who are allergic to eggs are at low risk of an anaphylactic reaction.

2. Contraindications of the vaccine are febrile illnesses. People with minor illnesses with or without fever (colds, or other upper respiratory tract infections) may be vaccinated. Those with more serious illnesses should not be vaccinated until recovery.

Allergies: Most children with a history of anaphylactic reactions to eggs have no unwanted reaction to the measles or MMR vaccine. But those who have experienced an anaphylactic reaction to topically or systemically administered neomycin should not receive the measles vaccine (most topical medications for eyes and ears have a neomycin component).

Thrombocytopenia (low platelet count): Platelets are the component in blood that help in clotting and stopping bleeding. Children who have a history of Thrombocytopenia may develop symptoms after vaccination.

Recent administration of immunoglobulin: Vaccine should be delayed for three months after a person has received an Ig prophylaxis for hepatitis A.

Tuberculosis: A tuberculin skin test should be done on the same day as the vaccination or four to six weeks after the MMR vaccination. Tuberculosis may be exacerbated by natural measles infection, but the live measles vaccine is not known to have a deleterious effect.

HIV infection: It is recommended that only those who have asymptomatic HIV infections, or those with symptomatic infections but who are not severely immunocompromised (low CD4), be vaccinated.

Pregnancy: Women who are pregnant or who are considering becoming pregnant within three months after vaccination should not be vaccinated.

Will your baby become sick after vaccination? There is a 5 percent to 15 percent chance your baby will get a fever after receiving the vaccine. But if you do not give your baby the vaccine, she will be at risk of a measles infection.

-- Dr. Donya