Vaccination FAQs

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Why do people need vaccines? What is immunization? What is immunity?

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Vaccines are medications that boost our ability to fight off certain diseases. Many of the vaccine-preventable diseases are highly contagious and even fatal in non-immunized individuals (Table 1). Prior to the development of vaccines, these diseases disabled or killed millions of people. Many people living in developed countries today do not appreciate the value of immunizations because the successful use of vaccines has almost eradicated many of these diseases. These diseases are still dangerous and can kill people who are not adequately protected from them.

Table 1: Vaccine-preventable diseases
Cervical cancer
Haemophilus influenza type B (Hib)
Hepatitis A
Hepatitis B
Human papillomavirus (HPV)
Influenza (flu)
Japanese encephalitis (JE)
Lyme disease
Meningococcal disease
Pertussis (whooping cough)
Pneumococcal disease
Poliomyelitis (polio)
Rotavirus (severe diarrhea)
Rubella (German measles)
Tetanus (lockjaw)
Varicella (chickenpox)
Yellow fever

Immunization is the act of receiving a vaccine. Immunity is the ability of the body to recognize specific infecting organisms as foreign and thereby protect against them.

How can people become immune (protected)?

Immunity (protection) can occur one of two ways:

  • The first way to become immune is by actually getting the natural disease. For many organisms, this confers immunity for life. When the person is exposed again to the organism, the immune system quickly reestablishes protection.
  • The second way to become immune is through the use of a vaccine. The vaccine interacts with the immune system and creates the same protection as if the person had the natural infections. This is done without being exposed to the risks involved with getting the natural infection.
Medically Reviewed by a Doctor on 9/25/2015

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Vaccinations - Indications Question: Have you followed the standard recommendations to vaccinate you or your children? Why or why not?
Vaccinations - Contraindications Question: Are you a person who has a condition that prevents you from being vaccinated? Please describe it.