The clinicians at Hyde Park Pediatrics are firmly committed to immunizing all children as early as possible, according to the guidelines that have been established by the Centers for Disease Control and endorsed by the American Academy of Pediatrics. The following article provides some facts about immunizations and dispels a few common myths.

Why immunize?

Because vaccines (also known as immunizations) have been so successful, many of the diseases that we immunize against have become very uncommon, and people forget how dangerous and deadly they can be. In the 1920’s, before routine vaccination began, 120 out of every 1000 babies died before their first birthday, mostly of infectious diseases that are now preventable.

Here are just some of the remarkable health improvements resulting from immunizations (click disease to see images):

Measles cases numbered four million per year before the introduction of the measles vaccine in 1964. About 450 children died of measles each year. In 2005 there were only 66 cases of measles, and almost all were associated with inadequately vaccinated people.

Mumps cases have decreased by 98 percent in the United States since the introduction of the vaccine in 1968. Before that, mumps caused infertility in about 25 percent of adolescent males who contracted it.

Rubella (German Measles) caused serious birth defects in about 20,000 babies a year in the US. Since the introduction of the MMR vaccine, birth defects from rubella have been eliminated.

Haemophilus Influenza B (H. Flu) causes meningitis, a life-threatening throat infection called epiglottitis, and overwhelming blood infections in children. Children under age five with H. Flu infections were often left deaf, brain-damaged, or dead. In 1984, before the vaccine against H. Flu was introduced, 20,000 people in the US developed serious H. Flu infections. Since widespread use of the vaccine began in 2002, only 34 children under age five have developed serious H. Flu infections.

Chickenpox cases in the US numbered about four million per year before routine vaccination. The disease accounted for 10,000 hospitalizations and 150 deaths per year. Since the vaccine was introduced, rates of chickenpox have dropped 80 percent, and death from chickenpox has decreased nearly 100 percent.

Pneumococcal vaccine protects against the most common cause of bacterial meningitis, severe pneumonia, and overwhelming blood infections in very young children. Before the vaccine was introduced, about 200 children per year died of invasive pneumococcal infections. Within two years of the introduction of the vaccine in 2000, the rate of serious pneumococcal illness in children fell by 69 percent. An unanticipated benefit of giving pneumococcal vaccine to children was that the rate of death among the elderly from pneumococcal infections also fell significantly.

The US incidence of Hepatitis B, an often deadly infection of the liver, has dropped 67 percent since universal immunization of children began. Currently almost all cases of Hepatitis B occur in unimmunized adults.

Tetanus is caused by a bacterium that lives in the environment all around us. The disease causes severe muscle spasms (tetany) throughout the body, including the jaw, which can “lock” and result in suffocation. All it takes to develop tetanus is a small puncture wound or cut that becomes contaminated by the tetanus-causing bacterium. In countries without tetanus-vaccine programs, tetanus is a common cause of childhood death. In the US, tetanus occurs most commonly in older adults who have allowed their vaccine-acquired immunity to wane.

Pertussis, or whooping cough, caused about 10,000 deaths per year in the US prior to the introduction of the vaccine. Most of these deaths occurred in young infants, who frequently develop pneumonia, seizures, and brain damage from the infection. In 1982, when the immunization rate was very high, there were only four pertussis deaths in the US. As a result of a subsequent decrease in pertussis vaccination, there has been an increase to about 25 deaths per year.
Paralytic polio and diphtheria, diseases that still kill many children world-wide, have been eliminated in the United States. However, it would take only a single infected person traveling from an endemic area and encountering an unimmunized American child to reintroduce these infections to the US.

What worries parents about immunizations?

Concern has been raised as to whether vaccines can cause autism. Several studies have conclusively disproven this association. Where did this concern come from? The MMR vaccine is usually given to children around 15 months—the same age at which the symptoms of autism often become apparent. As a result, people questioned whether the MMR vaccine could be causing the onset of autism. In 1998 researchers in England published a small study of 12 children with autism, suggesting that the MMR vaccine was responsible. This set off a media frenzy of accusations against the MMR vaccine. However, in 2002 a study was published in the New England Journal of Medicine, which showed definitively that MMR vaccine does not cause autism. In this study, information on every child born in Denmark between 1991 and 1998 was used. Of these 537,303 children, 440,655 (82 percent) had received MMR vaccine. The rate of autism or autism-spectrum disorders in the group of children immunized with MMR was slightly lower than that of the group that never received the vaccine. After this study was published, ten of the 13 scientists who published the 1998 article questioning the safety of the MMR vaccine retracted their concerns and stated publicly that they were convinced of the safety of the MMR vaccine.

Concern has also been expressed about the safety of the preservative thimerosal, which has been used to prevent bacterial contamination of vaccine vials. In Massachusetts, none of the vaccines distributed for use among children under age three contain thimerosal. In 1999 the preservative was removed from vaccines given to children less than three because of theoretical concerns about the safety of the mercury in thimerosal. However, there is no evidence that thimerosal in vaccines causes autism. In fact, a recent study comparing children through their seventh birthdays who received vaccines with thimerosal and those who received vaccines without the preservative found no increased risk of autism or other neurological problems.
Some parents worry that vaccines will harm their children’s immune systems. There is no scientific evidence to suggest that, as a result of receiving immunizations, children get more infections or have weaker immune systems. In fact, children today are much healthier than those of the pre-vaccine era. Bacteria, viruses, and other kinds of germs are around us all the time. A child will encounter numerous germs every time he puts his hand into his mouth, or his mouth on the breast, bottle, or pacifier. The immune system is capable of dealing with hundreds of organisms at a time. Vaccines simply provide a means of introducing certain germs to a child’s immune system that are critical for it to learn to fight.

All of the clinicians at Hyde Park Pediatrics believe that the recommended infant and toddler vaccines are an essential part of your child’s medical care. Vaccines need to be given according to their recommended schedule to prevent gaps in disease coverage which could result in your child’s acquiring a potentially deadly, vaccine-preventable illness. The younger the infant, the greater the risk of serious damage or death from these illnesses; consequently, any delay in immunizing will put an infant at risk. Several of the most important vaccines are first given at two months, because this is the youngest age at which the vaccines become effective. Children who have not been appropriately immunized and acquire these infections, even if they do not become severely ill, threaten the health of other more vulnerable people in our society, including very young infants who have not yet received their vaccines, the elderly, and people with chronic diseases.