The following vaccinations are among those most commonly recommended for children.

• DPT, or diphtheria/pertussis/tetanus, is designed to protect against three different diseases: diphtheria, a rare but potentially fatal disease that affects the upper respiratory tract, the heart, and kidneys; pertussis, or whooping cough, a disease that is particularly dangerous for children under one year of age and can lead to pneumonia, seizures, and other complications; and tetanus, a potentially deadly infection of the central nervous system.
• DT, or diphtheria/tetanus, is an alternative to DPT, without the pertussis vaccine. It is designed to protect against diphtheria and tetanus only.
• Hemophilus influenzae (H. flu.) meningitis type B vaccine, or Hib vaccine, protects against a common bacterial infection that can lead to meningitis, a potentially fatal brain disease. Complications of H. flu. meningitis include pneumonia, hearing loss, and possible learning disabilities. There is now a combination DPT and Hib vaccine available that reduces the number of injections a child must receive to be immunized against all of these diseases.
• The hepatitis B vaccine, the most recent addition to the list of routinely administered vaccines, protects against one of the more serious forms of hepatitis, hepatitis B. This is an infection of the liver that, while not highly contagious, can lead to chronic liver disease or even liver cancer. This vaccine is now being recommended for all children, starting a day or two after birth. Parents are also being encouraged to arrange for the vaccination of unimmunized older children and adolescents.
• MMR-or measles/mumps/rubella also works to prevent three different diseases: measles, a highly contagious viral disease characterized by fever and rash, whose danger lies in the possibility of such serious complications as pneumonia, strep infections, and encephalitis; mumps, a contagious viral disease that causes fever and swollen glands around the neck and throat (and, rarely, the testicles); and rubella, or German measles, a viral disease involving fever and a mild rash that causes relatively little discomfort to the affected child, but that can cause miscarriage, stillbirth, or birth defects if a woman is exposed to the virus during pregnancy. Because there have been outbreaks of measles among previously vaccinated college students in the past few years, it is now recommended that children receive a total of two MMR injections, the first at fifteen months and the second either before entering school or at the age of eleven or twelve years.
• The polio vaccine is designed to protect against poliomyelitis, an acute viral infection that can lead to paralysis and death. Vaccination against polio involves a more complicated set of decisions than other vaccinations do. Immunization against polio may be accomplished either by an injection of inactivated, dead vaccine, or by live vaccine, which is taken by mouth. The live vaccine present in the oral form appears to give somewhat better immunity than the injectible form does, and has therefore been generally recommended in the United States. However, it also poses a higher risk of complications. An estimated six or seven children come down with polio every year as a result of receiving this vaccine. For this reason, this form of polio vaccine is specifically not recommended for a child with a compromised immune system. Also, it is possible for an unimmunized person to contract polio from a child who has been given the live vaccine, even if the child has no noticeable reaction to it. This poses a particular danger if a child has friends or family members who have not been vaccinated, or who have impaired immune function. In such cases, the injectible, inactivated form is recommended. A newer, more potent form of the injectible vaccine now appears to give better immunity than the original one did, while still avoiding the risk of a child (or others with whom she comes in contact) getting the disease as a result of the immunization. Some doctors who recommend the oral, live vaccine take other measures to reduce the chance of a child contracting the virus from it, such as giving the injectible version for the first dose, then switching to the oral form for the additional doses.
• Immunization against rubella may be recommended if your child is a girl between thirteen and sixteen years old who has not received the MMR vaccine (see above) or had German measles.
• The tetanus toxoid vaccine protects against tetanus, an infection of the central nervous system that can be fatal. It is usually given to children in the form of a DPT or DT immunization (see above), but it can be administered individually.