Shot by shot: what you need to knowHepatitis B (Hep B): You can contract Hep B through unprotected sex, needle sharing, or from a transfusion of contaminated blood. This liver-damaging disease is also passed from mother to baby during delivery.
Diphtheria, Tetanus, Pertussis (DTaP): Fever and difficulty breathing are signs of diphtheria, a bacterial infection of the respiratory tract that can be fatal; tetanus (or lockjaw -- where the mouth is held shut by a continuous spasm) damages the central nervous system; and pertussis (whooping cough) causes severe coughing and may progress to pneumonia and even death.
Vac fact: A recent upsurge of pertussis has prompted the Centers for Disease Control and Prevention to recommend that parents get a Tdap shot (the type similar to DTaP), since 55 percent of infants who get whooping cough catch it from a caregiver.
Haemophilus influenzae type B (Hib): This shot fights haemophilus influenzae, which causes three potentially fatal illnesses: bacterial meningitis (infection of the fluid surrounding the brain and spinal cord) and epiglottitis (swelling of the windpipe), and pneumonia.
Polio (IPV): IPV protects against the polio virus, which infects the central nervous system, causing paralysis and possibly death. Polio is nearly extinct in the U.S., but a single case from abroad could ignite an outbreak, so babies still need to get the shot.
Measles, Mumps, Rubella (MMR): Measles causes rash and fever and may lead to ear infections, pneumonia, seizures, and possibly death. Mumps brings on fever and swollen glands and can lead to deafness and meningitis. Rubella (German measles) can cause rash and fever, and if you get it while pregnant from an unvaccinated child it may lead to miscarriage or birth defects. The MMR vaccine has a trace of egg in it; see "Influenza" for more details.
Vac fact: For immunizations to fight disease effectively, a large number of children must be vaccinated (this is called "herd immunity"). To keep measles in check, 95 percent of kids should receive the shot, but unfortunately, only 75 percent of them do, which can lead to outbreaks like those seen recently in Colorado.
Varicella (Varivax): Chicken pox can mean more than just a rash. Serious cases may trigger bad skin infections, pneumonia, encephalitis, and even death, but since this vaccine's introduction in 1996, it has been almost 100 percent effective against the worst side effects of the disease.
Vac fact: Here are some good reasons not to attend a "chicken pox party," where one kid naturally infects the others: the complications listed above; missed work (you'll be with your sick tot); and dangerous infection risks to adults who've never had the illness before -- mainly those who are pregnant (they could get pneumonia) or have compromised immune systems.
Pneumococcal conjugate (PCV): PCV protects against bacterial meningitis, pneumonia, and bacteremia (a blood infection), as well as chronic ear infections.
Vac fact: The number of earaches and the need for ear tubes due to pneumococcal (which require surgery to be implanted) has dropped dramatically since 2000, when use of this vaccine became routine.
Influenza: Fever, muscle ache, fatigue, sore throat, and congestion are the common flu symptoms, and kids spread the illness at a very high rate. The vaccine can be given as early as 6 months and should be continued until age 5.
Vac fact: This shot, along with MMR, contains a trace amount of egg; if your child has had a rash after eating eggs in the past or you have this allergy in your immediate family, speak with your doctor (reactions are rare, but she may want your child to stay in the office for 15 to 20 minutes after the shot).
Rotavirus: The highly contagious rotavirus virus, which is particularly common in the winter months, can cause fever, extreme vomiting, and diarrhea. There is no evidence of an increase in intussusception (where one part of the intestine collapses into another) among infants who received this vaccine, the newest one on the schedule, though some press reports have suggested otherwise, and the AAP continues to recommend the immunization.