In 1912, diphtheria killed 1,812 of every 100,000 American children. Measles killed 700 of every 100,000. Meningitis killed 1,150 of every 100,000 kids. Fast-forward to last year, when zero American children died of diphtheria or measles in 2011 – and the mortality rate for meningitis was approximately 2 cases per million people.
What caused this dramatic reduction? Vaccines.
So why is there a modern backlash against vaccines for babies, kids and teens? Two of the greatest impediments to successful vaccination of infants and children are misunderstandings and misinformation about side effects. (These will be the topic of my next blog post.) First, parents should understand the simple, life-saving concept behind these important shots – and how three main classes of vaccines that they’ll encounter in their pediatrician’s or family doctor’s office work.
Vaccines make use of the body’s own immune response to protect against dangerous infections. When a person develops an infection (like measles), the body develops a specific protective response (immune response) to the virus or bacteria behind it. This immune response does two things. First, it resolves the infection. Second, it prevents future infections with the same invader. Vaccines are designed to produce this lifesaving, protective effect WITHOUT the natural infection.
In general, you’ll encounter three types of vaccines when you take your child to the doctor:
Component vaccines contain a protein or sugar from the target virus or bacteria that has been altered so it can’t produce illness — but can produce an immune response. Most vaccines in current use are component vaccines, including vaccines for diphtheria, tetanus, pertussis, hepatitis B, Hemophilus influenzae type b (which can cause meningitis - a brain infection- in young children), Streptococcus pneumonia (the most common cause of ear infections, blood infections and meningitis in young children), and Neisseria meningitidis (the largest cause of bacterial meningitis in the U.S.) Side effects: Because these vaccines contain only a protein or modified sugar, side effects are limited mainly to local inflammation at the site of injection and occasionally fever.
Inactivated vaccines contain the complete virus or bacteria which have been killed chemically or thermally. The most common versions of these vaccines are the inactivated polio vaccine given to young children and the annual influenza vaccine. Side effects: Mainly redness and swelling at the injection site and, once in a while, fever.
Live, attenuated vaccines contain living viruses that have been altered in such a way that they illicit a broad-based immune response (including a response at the surface of the lungs and the intestines), but do not produce disease. Vaccines against mumps, measles, rubella, chickenpox and rotavirus are all live attenuated vaccines. Side effects: Soreness, fever, and mild rash. Rotavirus vaccine may make babies irritable or cause mild diarrhea or vomiting.
Additional information regarding the recommended schedules, uses, legal requirements and side effects of these vaccines can be found at the CDC website (www.cdc.gov/vaccines) and at www.healthychildren.org.
Have questions. Feel free to pose them, and I'll do my best to provide answers.
Stephen C. Aronoff, M.D., M.B.A., is the Waldo E. Nelson Chair of the Department of Pediatrics at Temple University Hospital and a professor at Temple University School of Medicine.