Vaccinations

Vaccinations are used to initiate or augment resistance to infectious diseases. The ultimate goal is to prevent, and in some cases eradicate, potentially serious, life-threatening diseases.

Vaccinations are used as a means of triggering acquired immunity. This is a specialized form of immunity that provides long-lasting protection against specific antigens which can cause certain diseases. This works because the immune system can learn to recognize dangerous invaders if they are presented to it in a weakened form.

When vaccinations are performed, small doses of the antigen (such as dead or weakened live viruses) are given to activate the immune system. When the immune system comes in contact with the antigens, it learns how to attack them and remembers what they look like. This allows the body to react quickly and efficiently when faced with the actual disease-causing organism. Vaccinations are one of the best means to protect against many contagious diseases.

Four different types of vaccinations are currently available.

• Attenuated (weakened) live virus is used in the measles, mumps, and rubella (MMR) vaccine and the varicella (chicken pox) vaccine. These vaccines last longer than other vaccines, but may cause serious infections in people with compromised immune systems.
• Killed (inactivated) viruses or bacteria used in some vaccinations. For example, the influenza vaccine uses killed virus. These vaccines are safe, even in people with compromised immune systems.
• Toxoid vaccines contain a toxin produced by the bacterium or virus. For example, the diphtheria and tetanus vaccines are actually toxoids.
• Biosynthetic vaccines contain synthetic "man-made" substances which appear to be antigens to the immune system. For example, the Hib (Haemophilus influenzae type B) conjugate vaccine is a biosynthetic vaccine.

Learn more about vaccinations at the Brenner Children’s Hospital web site.

Vaccinations