by Katie Porterfield
November 29, 2011

What are diphtheria, tetanus & pertussis?
The DTaP vaccine, according to the Centers for Disease Control and Prevention (CDC), protects against three serious bacterial diseases: diphtheria, tetanus, and pertussis.

Diphtheria is a bacterial infection involving the surface (mucus membrane) of the throat. It causes a thick gray coating on the back of the throat that makes it difficult to breathe. Other symptoms include sore throat, painful swallowing, fever, swollen glands, and weakness. Untreated, diphtheria can lead to paralysis, heart failure, kidney failure, and death. It is spread through contact with an infected person.

Tetanus results in painful tightening of the muscles, usually all over the body. Also known as “lockjaw,” the vaccine-preventable disease often causes the neck and jaw muscles to lock and prevents an infected person from opening his mouth or swallowing. Complete recovery can take months, and tetanus can be fatal if it isn’t treated. According to the CDC, 2 out of 10 tetanus cases leads to death. Unlike diphtheria and pertussis, tetanus doesn’t spread from person to person. Instead, the toxin-producing bacteria that cause the disease (which are found in soil, dust, and manure) enter the body through a break in the skin. Children, for example, can become infected while playing in the yard.

Commonly known as whooping cough, pertussis causes severe coughing spells that leave an infected person gasping for air. The disease can lead to pneumonia, seizures, brain damage, and death. Pertussis is caused by the bacteria, Bordetella pertussis and is spread through contact with an infected person. Once someone becomes infected, he or she will begin to exhibit symptoms within three to 12 days.

Why Should I vaccinate my child?
Diphtheria: Before a vaccine for diphtheria became available in the 1920s, diphtheria was one of the most common causes of illness and death among children. Since the late 1940s, with the introduction of universal childhood immunization, the disease has been well controlled in the U.S. Between 1980 and 2005, 55 cases of diphtheria were reported to the CDC’s National Notifiable Disease Surveillance System. Five of those cases were fatal and four out of those five deaths were among unvaccinated children.

Tetanus: The incidence of tetanus in the U.S. also decreased significantly after the introduction of tetanus toxoid vaccines in the 1940s, and the number of tetanus cases has continued to decrease through the years. The CDC reported 233 tetanus cases from 2001 through 2008—a 35 percent decrease from the number of cases reported during 1991 through 1998.

Pertussis: Like diphtheria, pertussis was a major cause of childhood mortality before the introduction of a vaccine in the 1940s. By 1980, the average incidence of pertussis had decreased significantly, but since then, the incidence of pertussis has increased, especially among 10–19 year olds and infants younger than 6 months old. About 17,000 cases of pertussis were reported in 2009 (and many more go unreported), and pertussis epidemics continue to occur every 3–5 years in the U.S. The most recent outbreak occurred in California just last year. From January to December 15, 2010, more than 7,800 cases of pertussis (including 10 infant deaths) were reported throughout the state—making it the most cases reported in 63 years.

How many doses will my child receive?
The DTaP vaccine is given as a series of five shots (injections), typically administered in the arm or thigh.

When is the vaccine given?
According to the CDC, children should receive one dose of the DTaP vaccine at the following ages:

• 2 months

• 4 months

• 6 months

• 15–18 months

• 4–6 years

What are the possible side effects?
The vaccine, according to the CDC, may lead to mild (common), moderate (uncommon), or severe (rare) side effects.

Mild problems, which occur more often after the fourth and fifth doses of the DTaP series, rather than after the earlier injections, include fever (up to about 1 child in 4), redness or swelling where the shot was given (up to about 1 child in 4), and swelling of the entire arm or leg in which the shot was given for one to seven days (up to about 1 child in 30). Other mild problems that generally occur one to three days after the shot include fussiness (up to about 1 child in 3), tiredness or poor appetite (up to about 1 child in 10), and vomiting (up to about 1 child in 50).

Moderate problems include seizure (jerking or staring, which occurs in about 1 child out of 1,400), non-stop crying for three hours or more (up to about 1 child out of 1,000), high fever over 105° F (about 1 child out of 16,000).

Other very rare, severe problems that have been reported after the DTaP vaccine include long-term seizures, coma or lowered consciousness, and permanent brain damage. According to the CDC, the above problems are so rare that it is difficult to tell if the vaccine causes them.

When should I call a doctor?
As with any vaccine, parents should contact a health care provider if their child experiences an allergic reaction (which occurs in less than one out of a million doses and most likely happens within a few minutes to a few hours of receiving the shot). Signs of an allergic reaction include difficulty breathing, hoarseness or wheezing, swelling of the throat, weakness, paleness, fast heartbeat, hives, and dizziness.

Katie Porterfield is a freelance writer and former magazine editor in Nashville, Tennessee. She is mom to twin boys.