Blog Post


The importance of immunizations: part 1 

By Lori Patterson, M.D., FAAP

When it comes to their children’s immunizations, some parents are choosing to listen to more than their doctor for information. Parents and caregivers are getting medical advice from message boards, blogs and other online sources. As a result, concerns and rumors have spread regarding the safety and purpose of vaccines. Here, Dr. Lori Patterson, pediatric infectious disease specialist, responds to common questions and misconceptions of immunizations.


How do immunizations work?

A:  A vaccine contains pieces of a dead or weakened disease-producing germ. When those pieces are injected (or swallowed for a few vaccines), the body recognizes them as “not self” and makes antibodies (protective proteins) against them. This gives the person immunity against that specific infection, so the next time the individual “runs into” that live germ, his or her body can fight it off before it has a chance to make the person sick.


Will vaccines weaken my child’s immune system?

A: No. They actually strengthen the immune system by making it able to respond more quickly to the germs the person has been vaccinated against.


Can immunizations cause the disease it is supposed to prevent?

A: It is impossible to develop a disease from vaccines made with dead bacteria or viruses. Only vaccines made with weakened live viruses – like the measles-mumps-rubella vaccine (MMR) – could make a child develop a mild case of the disease, but it is usually less severe than the illness itself.  The risk of significant disease from vaccination is extremely small.

“A flu shot can reduce a person’s chances of getting the flu by up to 80% during flu season.”


Can immunizations cause a bad reaction in my child?

A: Common, minor reactions to vaccines might include soreness and tenderness where the shot was given, swelling where the shot was given or fever.  Of the millions of children vaccinated every year, very few experience severe side effects. In rare cases, a child may have an allergic reaction or a seizure. Before vaccines are given, notify the doctor of your child’s history of allergies caused by food or medications. The risk of a significant reaction is much, much less than the risks posed by the diseases themselves.


Why are new flu shots required every year?

A: Influenza is a virus that constantly changes every year, and the vaccine must change with it. A new flu shot is required each year to protect against the newest strain. A flu shot can reduce a person’s chances of getting the flu by up to 80% during flu season. The vaccine doesn’t protect against all strains of the flu, and it’s still possible to contract the virus. However, symptoms are usually milder and easier to get over if a person has been vaccinated.  Also, immunity from a flu vaccine only lasts for a year or so.

Look for more information on immunizations and answers from Dr. Lori Patterson in the next issue of Knoxville Parent.

Lori Patterson, M.D., FAAP specializes in pediatric medicine and infectious disease at East Tennessee Children’s Hospital.  For more information please visit the Children’s Hospital website (

Related posts