By Laird Harrison
What are immunizations?
Immunizations are a way of teaching the body how to fight a particular disease. Although the body's natural defense mechanisms are triggered whenever it encounters germs, vaccines target a specific enemy. Vaccines contain dead or weakened viruses or bacteria or traces of the poisons they produce. When you're vaccinated, your body makes cells especially equipped to destroy those agents. The cells remain on guard in case you are ever exposed to the actual diseases.
Why should my child be immunized?
Immunization can prevent serious contagious diseases such as polio, which once killed or crippled thousands of children. These diseases are now rare among children in the United States precisely because immunization programs have been so successful. But except for smallpox, no infectious disease has been eradicated worldwide. Some illnesses, such as pertussis (whooping cough) are still common among adults in the United States; others, such as diphtheria, measles, and rubella are occasionally brought here by travelers. So there is always a chance of your child being exposed. When some countries experimented with cutting back on pertussis vaccinations in the 1970s, the number of children who died from the disease increased sharply.
When should my child be immunized?
The nation's leading health organizations recommend a series of 10 vaccinations for common childhood diseases. The recommended schedule, designed to protect your child at the earliest age that the vaccines can be safely given, starts immediately after birth and continues until adolescence [See immunizations schedule]. Most public schools require proof of these immunizations before a child can attend class. And if your family has travel plans, special immunizations may be in order, depending on your destination; ask your doctor, especially if you're going outside the United States, especially to a developing country.
How well does immunization work?
No vaccine works all the time, but most common childhood immunizations are more than 90 percent effective once the series has been completed. Chances of success increase with each dose in a series -- in fact, a child exposed to a live polio virus after receiving all the recommended polio vaccinations would run less than a 1 percent risk of contracting the disease.
What are the risks from immunization?
It's no fun to have your baby stuck with a needle, but the pain quickly fades, while the protection can last a lifetime. A few children suffer side effects, most commonly soreness at the injection site or fever -- both treatable with acetaminophen. (Don't use aspirin for children and teenagers because of the risk of Reye's syndrome, a rare but potentially life-threatening disorder.) A small number of children are susceptible to febrile seizures when their temperature gets very high, but the seizure usually passes in 60 seconds and rarely causes harm.
Since 2000, the American Academy of Pediatrics has recommended that children receive the inactivated polio vaccine (IPV), given as injections, and not the oral polio vaccine, which contains a weakened but live virus. Some cases, however, may definitely call for a live vaccine -- for example, if a family plans to travel to a country where a wild type of poliovirus still thrives.
Controversy has also arisen regarding the pertussis or whooping cough vaccine, given as a shot for diphtheria, tetanus, and pertussis. Critics claim the whole-cell version of the vaccine, known as DTP, can lead to brain damage, convulsions, and Reye's syndrome, but the American Academy of Pediatrics says there's no conclusive evidence of those risks. Although severe reactions to the vaccine are extremely rare, an acellular version (one that contains no pertussis cells) known as DTaP is now the recommended vaccine for children. DTaP has been available since 1991 and in use for infants since 1996. It causes fewer and less severe side effects.
Occasionally vaccination for measles, mumps, and rubella (MMR) causes mild symptoms of those diseases, such as a rash or swelling under the ears. And in rare cases, the chemicals that hold the killed or weakened germs can cause a powerful allergic reaction. But the risks of life-threatening or crippling reactions are extremely low; for example, about one in a million children suffer a severe reaction to MMR. By comparison, three in 1,000 people in the U.S. who catch measles die from it.
Why was the rotavirus vaccine suspended then reinstated?
In July 1999, the Centers for Disease Control and Prevention suspended the only approved vaccine for rotavirus (a common virus which causes severe diarrhea), saying there was a potential health risk of a serious intestinal problem. In 2006, the CDCs Advisory Committee on Immunization Practices (ACIP) recommended a newly designed vaccine for infants. The ACIP made its recommendation after reviewing a study involving 70,000 children in which the vaccine showed no association with the previous ones risks. In February 2007, the CDC adopted the new Rotavirus vaccine in its immunization schedule.
When should I call a doctor?
Call your doctor any time you are concerned about the effects of a vaccine, but especially if your child has a fever of 105 degrees or more; has a seizure, collapses or appears limp, listless, or in shock; has an unusual high-pitched cry, or cries inconsolably for more than three hours. Call 911 if your child has difficulty breathing or if a seizure lasts for more than a few moments.
When should I avoid having my child immunized?
Inform your doctor if your child has leukemia, suffers from an immune disorder (such as AIDS), has recently taken a corticosteroid drug, has had a bad reaction to a previous vaccination, is allergic to eggs or antibiotics, has taken gamma globulin or has received a blood transfusion within 3 months or has recently received any other vaccines; these may be situations where vaccination should be avoided or postponed. Before any vaccination, make sure the person giving the vaccine knows about any health problem your child has or medication your child is taking.
What if I can't afford to pay for the immunizations?
Many public clinics offer free immunizations; check with your county health department to find such a program near you.
Epidemiology and prevention of vaccine-preventable dieseases. 5th ed. Atlanta: Centers for Disease Control and Prevention, 1999.
Centers for Disease Control. General Recommendations on Immunization. February 2002.
Centers for Disease Control. 2010 Childhood & Adolescent Immunization Schedules.
Centers for Disease Control. CDCs Advisory Committee Recommends New Vaccine to Prevent Rotavirus. February 2006.
Centers for Disease Control. What Would Happen If We Stopped Vaccinations? May 2007.