A vaccinated child is usually protected from diseases, especially those that are related to smallpox or measles, by vaccination. A vaccine protects not only against a specific disease but also against its symptoms. A vaccination typically contains a virus-like organism that looks like a microbe-caused infectious disease and is usually made of one or more of the microbe’s toxins, its viruses, or even one of its proteins on its surface. The organism is introduced into the body by way of a vaccine needle, and then it is allowed to multiply. The virus is then able to attack and kill the body’s healthy cells before they can reproduce and cause disease.

The vaccines that are used to protect children and young adults against certain diseases usually contain at least one component which allows the body to develop the antibody needed to fight off the virus. Antibodies that have been developed are normally produced by the body when it is exposed to the foreign object, and then it is passed on from one person to another, resulting in protection for the individual. Some vaccines are given in doses over an extended period of time. This ensures that the body produces enough antibodies to counteract any possible threat to the body. Some vaccines, such as the Hepatitis A vaccine, may need to be renewed every year if the body has not produced enough antibodies. Other vaccines, however, are given in a single shot, and thus require no renewal.

Even though vaccines are very helpful and safe, some diseases that are treated with them, including measles, mumps, and rubella (or MMR) and the chicken pox, can cause serious side effects if not given the right dose. Many children develop allergies or asthma after receiving these vaccines. While most children grow out of their childhood illnesses, some do, and so their families should always remember that the vaccines cannot make up for a lack of proper care during childhood. Also, if a child develops a vaccine-preventable illness, the family will not have to bear the medical costs associated with that illness and therefore, will save on medical insurance premiums.