Vaccines Explained

A vaccine is a substance that can prevent your body from getting sick. You get vaccines through vaccinations, also called immunizations or immunization shots.

Vaccines contain germs that have been either weakened or killed (depending on the vaccine). When your body receives the vaccine, your immune system senses the germs and learns how to fight them off. So when the same type of germs attack your body later, your immune system already knows what to do so you don’t get sick.

Talk to your health care provider about the vaccines recommended for you and your family. Immunization schedules published by the Centers for Disease Control and Prevention can also help you know what vaccinations you need at each age.

Vaccines may be available at doctors’ offices, public health clinics or other community locations, such as schools, pharmacies or places of worship.

Vaccines for Children

Children routinely get vaccinations to prevent dangerous childhood diseases that can cause serious complications, even death.

Childhood vaccines prevent:

  • Diphtheria
  • Haemophilus influenza type B
  • Hepatitis A
  • Hepatitis B
  • Human papillomavirus (HPV)
  • Measles
  • Meningococcal meningitis
  • Mumps
  • Pertussis (whooping cough)
  • Pneumococcal meningitis
  • Polio
  • Rotavirus
  • Rubella (German measles)
  • Tetanus
  • Varicella (chickenpox)

Vaccines for Adults

People of all ages – not just children – need vaccinations. Some childhood vaccines may not be effective through adulthood. “Boosters” help provide lifelong immunity.

Adults should talk to their health care provider about getting:

  • Follow-up immunizations for tetanus, diphtheria, pertussis and more
  • Specific vaccines before traveling to another country
  • Flu vaccine – the Centers for Disease Control and Prevention recommends annual flu vaccine for everyone 6 months and older

Vaccine Side Effects

As with any medicine, there is a risk of side effects from vaccines. Some of the most common are slight fever, rash or soreness where the vaccine was injected.

Serious reactions to vaccines are rare. Most health care providers agree that the risk of serious reaction is far less than the risk of serious disease from not getting vaccinated.

However, always talk to your health care provider if you or your child has an allergy to eggs, gelatin, yeast or latex, which may be part of the vaccine or injection device.

Vaccine side effects, including serious allergic reactions, can include:

  • Breathing difficulty
  • Dizziness
  • Fast heart beat
  • High fever
  • Hives
  • Hoarseness or wheezing
  • Paleness
  • Seizure
  • Weakness

Get medical help immediately if you or your child shows these signs.

Who Should Not Be Vaccinated?

Talk to your health care provider about whether you should or should not be vaccinated.

Sometimes, people should avoid vaccines if they:

  • Have a fever or significant illness
  • Have a suppressed immune system – which can be due to AIDS, leukemia, cancer, steroids, chemotherapy or radiation
  • Have severe allergies to eggs, gelatin, yeast or latex
  • Had an adverse reaction to a previous vaccine