Diphtheria, tetanus and pertussis are prevented by a childhood vaccine, called DTaP, and a newer vaccine for adolescents and adults, called Tdap.
The DTaP and Tdap vaccines both protect against three bacterial infections: diphtheria, tetanus and pertussis, whereas the Td vaccine only protects against diphtheria and tetanus. In addition, the vaccines vary in terms of who should receive them and the quantities of vaccine proteins they contain:
The capital "D" in DTaP and the lower case “d” in Tdap and Td stand for diphtheria.
The dangers associated with diphtheria come from the toxin released by the bacterium, Corynebacterium diphtheriae. The toxin makes it difficult for children to breathe and swallow, but it also attacks the heart, kidneys and nerves.
In the 1920s, diphtheria was a common cause of death in children and adolescents. At its peak, about 150,000 cases of diphtheria occurred in the United States every year! The diphtheria vaccine, first used in the United States in the early 1940s, has virtually eliminated the disease. Now we see fewer than two cases a year.
Countries in Eastern Europe, especially Russia, suffered severe outbreaks of diphtheria in the mid-1990s. The outbreaks coincided with a noticeable drop in immunization rates.
The bacteria that causes diphtheria makes a harmful protein, called a toxin. People who develop an immune response to this toxin are protected against the disease. The diphtheria vaccine is made by taking the diphtheria toxin and inactivating it with a chemical. The inactivated toxin is called a "toxoid." Once injected, the toxoid causes an immune response to the toxin, but, unlike the toxin, doesn't cause disease.
The diphtheria vaccine can cause mild side effects such as pain or soreness in the local area of the shot and occasionally a low-grade fever.
Diphtheria is an extremely rare cause of disease in the United States. Over the past 20 years there have been only about 25 cases of diphtheria causing five deaths. The last time someone died from diphtheria in the United States was in 2003. Most cases of diphtheria are imported; in fact, there have been no cases in U.S. residents since 1999. On the other hand, the diphtheria vaccine has no serious side effects. Therefore, although the risk of disease and death from diphtheria is very small, the risk of severe adverse reactions or death from the diphtheria vaccine is zero. In addition drops in immunization rates in Eastern Europe and Russia taught us how quickly outbreaks of diphtheria can return. For these reasons, the benefits of the diphtheria vaccine outweigh its risks.
The diphtheria vaccine does not protect people against diphtheria for the rest of their lives. Protection against diphtheria fades over time. That's why it's important to receive booster doses of vaccines containing diphtheria every 10 years, starting at age 11 or 12. See DTaP, Tdap and Td vaccines.
The capital "T" in DTaP, Tdap and Td stands for tetanus.
Tetanus is another disease caused by a toxin-releasing bacterium, Clostridium tetani. Unlike most vaccine-preventable diseases, tetanus is not a disease that you catch from someone else. The bacteria live in the soil and usually enter the body following a puncture wound of the skin. Items likely to be contaminated with the tetanus bacteria include nails or pieces of glass that were lying on the ground. Once under the skin, the bacteria make a toxin that causes muscle spasms. If these spasms affect the throat and jaw (lockjaw), they can interfere with breathing, causing suffocation. The tetanus toxin can also damage the heart.
Given the playful, adventurous, and oftentimes injury-prone nature of children, it's important to immunize them against tetanus. Hand washing and bathing do little once the bacteria actually get under the skin.
The bacteria that causes tetanus makes a harmful protein, called a toxin. The name of the tetanus toxin is tetanospasmin. People who develop an immune response to this toxin are protected against tetanus. The tetanus vaccine is made by taking the tetanus toxin and inactivating it with a chemical. The inactivated toxin is called a "toxoid." Once injected, the toxoid elicits an immune response against the toxin, but, unlike the toxin, doesn't cause disease.
Like the diphtheria vaccine, the tetanus vaccine can cause mild side effects such as pain or soreness in the local area of the shot and occasionally a low-grade fever.
The tetanus vaccine is also a rare cause of a severe allergic reaction. It is estimated that this allergic reaction could occur in about one of every 1 million children who receive the tetanus vaccine, and could include hives, difficulty breathing or a lower blood pressure. The allergic reaction can be treated with medications.
Every 10 years, people should receive the tetanus and diphtheria vaccines. Since most children complete their initial series of diphtheria and tetanus vaccines (given as part of the combination vaccine called DTaP) by 4-6 years of age, the next booster dose occurs during adolescence.
Unlike immunity that follows vaccination with live, "weakened" viruses (such as measles, mumps, rubella or varicella vaccines), immunity to inactivated bacterial toxins (such as tetanus and diphtheria vaccines) fades over time. Surveys also indicate that tetanus, in particular, tends to infect more people as they age. In fact, most people who die from tetanus (as many as 15 per year) are elderly adults.
The American Academy of Pediatrics (AAP) and the Center for Disease Control and Prevention (CDC) recommend that teenagers and adults should receive the Tdap for their next booster, starting at the age of 11 or 12 years old. Tetanus-diphtheria boosters should be received every 10 years thereafter. See DTaP, Tdap and Td vaccines.
Although tetanus bacteria are everywhere, tetanus is an uncommon cause of disease in the United States. But it’s probably not as rare as you may think. Between 2006 and 2011, an average of 24 cases of tetanus was reported each year in the United States with four or five deaths. On the other hand, although the tetanus vaccine can be a very rare cause of a short-lived allergic reaction called "anaphylaxis," the tetanus vaccine does not cause death. Therefore, the benefits of the tetanus vaccine outweigh its risks. In addition, because most of the disease and death from tetanus occur in the elderly, it is important to get booster immunizations every 10 years.
The capital "P" in DTaP and the lowercase “p” in Tdap stand for pertussis.
Pertussis (widely known as whooping cough) is one of the most contagious diseases around. Caused by a bacterium (Bordetella pertussis), whooping cough makes children cough uncontrollably. The cough is often so hard and so persistent that children can't catch their breath, and make a "whooping" sound when they attempt to breathe in against a windpipe severely narrowed by mucus. The cough can be so violent that people with pertussis crack ribs, break blood vessels, or develop hernias. Pneumonia or seizures can also develop. Young infants can also experience bouts of apnea.
Pertussis is unusual in that most children catch the disease from adults and not from other children. Because pertussis is often misdiagnosed and underdiagnosed, people do not always realize how common it is. In fact, it is estimated that every year in the United States between 600,000 and 900,000 adults and adolescents get pertussis!
Whooping cough is highly contagious and deadly. Prior to the vaccine, pertussis caused about 8,000 deaths in the United States every year. Now about 10 children die every year from pertussis.
The bacteria that cause pertussis make several harmful proteins, called toxins. People who develop an immune response to some of these toxins are protected against disease. The pertussis vaccine is made by taking two to five of these toxins and inactivating them with a chemical. The inactivated toxins are called "toxoids." Once injected, the toxoids elicit an immune response against the toxins, but, unlike the toxins, don't cause disease.
The latest version of the pertussis vaccine was released in the fall of 1996. This vaccine is called the "acellular" pertussis vaccine (or aP) and is purer than the old "whole cell" pertussis vaccine. The "old" pertussis vaccine still contained a killed form of the whole pertussis bacteria. Because individual bacteria are sometimes called cells, the "old" pertussis vaccine was called the "whole-cell" vaccine. On the other hand, the new pertussis vaccine takes advantage of advances in protein chemistry and protein purification. Because the whole killed pertussis bacteria are no longer present, the "new" pertussis vaccine is called the "acellular" vaccine.
The "old" pertussis vaccine, called the "whole cell" vaccine, had a high rate of mild and severe side effects. Mild side effects such as pain and tenderness where the shot was given, fever, fretfulness and drowsiness occurred in as many as one-half to one-third of children who received the vaccine. Severe side effects, such as persistent, inconsolable crying occurred in one of every 100 doses, fever greater than 105 degrees occurred in one of every 330 doses, and seizures with fever occurred in one of every 1,750 doses.
The new "acellular" pertussis vaccine, the one that has been in use in the United States since 1996, has much lower rates of both mild and severe side effects. Mild side effects such as pain and tenderness at the injection site occur in about one-third of children, most often after the fourth or fifth dose. More severe reactions occur in about one of every 10,000 children. Severe reactions can include fever of 105 degrees or higher, fever-associated seizures, inconsolable crying, or hypotonic-hyporesponsive syndrome, a condition in which a child can become listless and lethargic with poor muscle tone for several hours. (see Are vaccines safe?).
Unfortunately, recent data suggests that the tradeoff for increased safety was decreased vaccine effectiveness. Children who received the “acellular” version of pertussis vaccine become susceptible more quickly than those who received the “whole-cell” version. However, it is unlikely that we would return to using the older version; instead, additional booster doses may be recommended until a newer version of the vaccine that is both safe and more effective can be developed.
Pertussis is common in teenagers and adults. Therefore, a vaccine to prevent pertussis in teenagers and adults is of great benefit. However, the "old" whole-cell pertussis vaccine and the "acellular" pertussis vaccine for young children (part of the DTaP combination vaccine) had a high rate of side effects when given to people older than 7 years of age. A newer "acellular" pertussis-containing vaccine is available for older children and adults (part of the Tdap vaccine). Because adolescents and adults can transmit this disease to infants who are too young to have received their series of the DTaP vaccine, it is imperative that adults around the baby are immune. The phenomenon in public health is called “cocooning” because the immunized adolescents and adults essentially provide a barrier around the baby to keep pertussis infections at bay. Parents, grandparents and childcare providers should all be immunized before the baby is born. See Tdap and also see Vaccines During Pregnancy.
This question is best answered by taking a look at the side effects of the old pertussis vaccine. The old pertussis vaccine had a high rate of severe side effects such as persistent inconsolable crying, fever higher than 105 degrees, and seizures with fever. Due to negative publicity surrounding this vaccine, the use of the pertussis vaccine decreased in many areas of the world. For example, in Japan, children stopped receiving the pertussis vaccine by 1975. In the three years before the vaccine was discontinued, there were 400 cases of pertussis and 10 deaths from pertussis. In the three years after the pertussis vaccine was discontinued, there were 13,000 cases of pertussis and 113 deaths from pertussis! It should be noted that although the side effects of the old pertussis vaccine were high, no child ever died from pertussis vaccine.
The Japanese Ministry of Health, realizing how costly its error had been, soon reinstituted the use of pertussis vaccine. The children of Japan proved that the benefits of the old pertussis vaccine clearly outweighed the risks. The new "acellular" pertussis vaccine has a much lower risk of severe side effects than the old "whole cell" vaccine.
Pertussis is very common in the United States. More than more than 41,000 cases of pertussis and 18 deaths were reported to the CDC during 2012. However because of underdiagnosis and misdiagnosis, this number is likely to be a vast underestimate of the number of cases that actually occured. It is estimated that most years between 600,000 to 900,000 cases occur in adolescents and adults. Sadly, most of the deaths from pertussis occur in young infants who struggle to breathe against a narrowed windpipe, leading them to turn blue or suffer spells of apnea. Because the pertussis vaccine does not cause death, the benefits of the pertussis vaccine clearly outweigh its risks.
|Infants and young children (DTaP)
Adolescents and adults (Tdap)
|Diseases Risks||Vaccine Risks|
Reviewed by: Paul A. Offit, MD
Date: March 2013
Materials in this section are updated as new information becomes available. The Vaccine Education Center staff regularly reviews materials for accuracy.
You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel.