Vaccines: Your child's first line of defense against illness

Worried about your child's vaccines? A Mayo Clinic specialist addresses common questions and concerns about childhood vaccines.

Jay Hoecker, M.D.

Childhood vaccines protect children from a range of serious diseases. Yet you may wonder about the benefits and risks of childhood vaccines. Here, Jay Hoecker, M.D., a pediatrics specialist at Mayo Clinic, Rochester, Minn., responds to questions and concerns you might have about your child's vaccines.

Why are vaccines given to children when they're so young?

Childhood vaccines offer protection from a variety of serious or potentially fatal diseases. Early vaccination is essential because these diseases are most likely to occur when a child is very young and the risk of complications is greatest. If we wait to vaccinate until a child is older, it may be too late.

What are the legal requirements for childhood vaccines?

In the United States, each state has specific immunization requirements that must be met before a child can enter school. A list of required immunizations is available from the state health department or local school system. All 50 states allow vaccination exemptions for medical reasons. Most states have exemption clauses for parents who choose not to vaccinate their children due to religious beliefs, and some states allow exemptions for personal beliefs. Parents who choose not to vaccinate their children must usually sign a waiver of responsibility.

Is the immunity a child gets from a vaccine as strong as the immunity he or she would get from a natural infection?

Immunity from a vaccine is generally as strong as immunity following a natural infection — without illness or the risk of serious effects of disease, such as disability or even death. Vaccines simply help your child's immune system do its work.

Why are booster shots needed?

Some vaccines, such as tetanus and pertussis, don't provide lifelong immunity. Regular booster shots are needed to maintain immunity.

Could combination vaccines be too much for a child's immune system to handle at one time?

Children are exposed to many different germs every day. The introduction of several weakened or killed disease strains in a combination vaccine is no different. Studies show that combination vaccines are safe and effective, even for infants. Better yet, combination vaccines offer protection from various diseases more quickly and with fewer shots than would a series of individual vaccines given separately over the course of weeks or months.

Do vaccines have any side effects?

Vaccines can cause a low-grade fever and soreness, redness or swelling at the injection site. Some vaccines cause a headache, fatigue or loss of appetite. Rarely, a child may experience a neurological side effect, such as a seizure. For healthy children, the benefits far outweigh the rare risks of vaccination. If you're concerned that your child might be having a vaccine reaction, contact your child's doctor immediately or go to an emergency room.

Is there a connection between autism and childhood vaccines?

Researchers haven't found a connection between autism and childhood vaccines. Although signs of autism may appear at about the same time children receive certain vaccines — such as the measles, mumps and rubella (MMR) vaccine — this is simply a coincidence.

Are there times when a child shouldn't be vaccinated?

Vaccines aren't given to children who have known allergies to specific vaccine components. Likewise, if your child develops a life-threatening reaction to a particular vaccine, further doses of that vaccine won't be given. If your child has a moderate or severe illness on vaccination day, the vaccination may need to be postponed. The common cold or an ear infection isn't usually a reason to avoid or postpone vaccination.

What happens if a child misses doses of certain vaccines?

Catch-up vaccinations are available for most vaccines. It usually isn't necessary to repeat earlier doses of a particular vaccine.

Is it OK to skip certain vaccines if you have safety concerns?

In general, skipping vaccines isn't a good idea. This can leave your child vulnerable to potentially serious diseases that could otherwise be avoided. If you have reservations about particular vaccines, discuss your concerns with your child's doctor.

What's the best way to comfort a child during a shot?

Stay calm and relaxed. Hold your child and talk with him or her during the shot. Offer a favorite blanket, stuffed animal or toy for comfort and distraction. After the shot, use an ice pack to reduce redness and swelling near the injection site. If your child is uncomfortable, give him or her acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin, others). Read the label instructions for the correct dose. Don't give aspirin to anyone younger than age 19.