Vaccine Information

Entry last updated: 04/25/2006

- Understanding the Disease
- Available Vaccines
- History of the Vaccine
- Who Should and Should Not Receive the Vaccine
- Dose Schedule
- Effectiveness of the Vaccine
- Known Side Effects
- Related Issues
- Key References and Sources of Additional Information
- State Vaccine Requirements
- Important Facts for Parents to Know
- Frequently Asked Questions
- CDC Vaccine Information Statement

Understanding the Disease

Pertussis is a bacterial infection caused by Bordetella pertussis. The germ is spread when infected people cough or sneeze.

Children with pertussis have decreased ability to cough up respiratory secretions and develop thick, glue-like mucus in the windpipe. This causes severe coughing spells that make it difficult for them to eat, drink, or breathe. The child may suffer from coughing spells for two to three weeks or longer. Sometimes the child coughs several times before breathing in; when the child finally does breathe in there is often a loud gasp or "whooping" sound. The disease is most severe when it occurs early in life; it often requires hospitalization.

The majority of pertussis-related deaths are in young infants which may occur when other bacteria take the opportunity to invade the sick infant's lungs. Primary pertussis pneumonia also may be life-threatening in infancy. In 1997, adolescents and adults accounted for 46% of reported cases of pertussis, and they are often the ones who spread this disease to infants and children.

Pertussis is one of the most contagious human diseases, so it is a great risk to those who are unvaccinated. Pertussis will develop in 90% of unvaccinated children living with someone with pertussis, and in 50% to 80% of unvaccinated children who attend school or daycare with someone with pertussis. Approximately 50 out of every 10,000 people who develop pertussis die from the disease.

Between 1940-1945, before widespread vaccination, as many as 147,000 cases of pertussis were reported in the United States each year, with approximately 8,000 deaths caused by the disease. Over the past few years the number of reported cases of pertussis has increased annually from 9,771 in 2002 to 25, 827 in 2004 according to CDC. Worldwide, there are an estimated 300,000 annual deaths due to pertussis.

In 2004, adolescents 11-18 years of age and adults 19-64 years of age accounted for 34% and 27% of the cases of pertussis in the US. The true numbers are probably much higher in these age ranges because of the illness often not being recognized. These cases are very important because teenagers and adults with pertussis can transmit the infection to other people, including infants who are at greatest risk for complications and death. Recommendations for the use of newly licensed vaccines for adolescents and adults have recently been published.

Available Vaccines

No pertussis-only vaccine is available. The pertussis vaccine is available as: 

• DTaP (Diphtheria-Tetanus-acellular Pertussis vaccine) 
• DTaP in combination with Haemophilus influenzae type b (Hib) vaccine
• DTaP in combination with hepatitis B and inactivated polio vaccines
• Tdap (Diphtheria-Tetanus-acellular Pertussis vaccine)

Vaccines containing the whole cell pertussis component (DTP) are no longer recommended for use in the United States and are not listed here. Vaccines containing lower amounts of diphtheria toxoid?abbreviated with a small d?are utilized in persons 7 years of age or older. Pertussis component-containing vaccines are not available for children 7-9 years of age.

Product Name: Tripedia® (DTaP)
Manufacturer: Sanofi Pasteur
Year licensed: 2001
Note: As of May 2001, Aventis was in the process of transitioning to their new preservative-free DTaP vaccine; however, some supplies of the original Tripedia® may still be in use.

Product Name: Infanrix®  (DTaP)
Manufacturer: GlaxoSmithKline
Year licensed: 1997

Product Name: TriHIBit® (DtaP and Hib conjugate vaccine)
Manufacturer: Sanofi Pasteur
Year licensed: 2001
Note: As of May 2001, Aventis was in the process of transitioning to their new preservative-free DTaP and Hib conjugate vaccine; however, some supplies of the original TriHIBit® may still be in use.

Product Name: DAPTACEL^TM (DTaP)
Manufacturer: Sanofi Pasteur
Year Licensed: 2002

Product Name: Pediarix^TM (DTaP, hepatitis B, and inactivated polio vaccines)
Manufacturer: GlaxoSmithKline
Year licensed: 2002

Product Name: BOOSTRIX^TM (Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine, Adsorbed for use in 10-18 year old persons  - preservative free) (Tdap)
Manufacturer: GlaxoSmithKline Biologicals
Year licensed: 2005

Product Name: ADACEL^TM (Tetanus and Diphtheria Toxoids Adsorbed for use in 11-64 year old persons - preservative free) (Tdap)
Manufacturer: Sanofi Pasteur
Year licensed: 2005

For information on the thimerosal content in these vaccines, see the Food and Drug Administration at www.fda.gov/cber/vaccine/thimerosal.htm#t3 or Johns Hopkins University's Institute for Vaccine Safety at www.vaccinesafety.edu/thi-table.htm

History of the Vaccine

In the mid-1940s, the whole cell pertussis vaccine was combined with vaccines against tetanus and diphtheria. The combined DTP vaccine soon was routinely used in the United States, but is no longer recommended.

In 1991, the Food and Drug Administration licensed the DTaP vaccine (diphtheria-tetanus-acellular pertussis). While DTP was made using whole cells of the pertussis germ, DTaP is made using only small, purified snippets of the germs. Fewer side effects have been reported with DTaP than with DTP. In 1991, DTaP was licensed for only the fourth and fifth doses in the series, and in 1997 it was licensed for all five doses.

Two new vaccines were licensed by the Food and Drug Administration for use in older individuals in 2005. These vaccines are abbreviated Tdap. One, BOOSTRIX®, for persons 10-18 years of age, the other ADACEL® for persons 11-64 years of age.

Who Should and Should Not Receive this Vaccine

Who should receive the vaccine? 

• Most infants and children younger than seven years of age should receive DTaP beginning at two months of age.
• 11-18 year olds should receive a single dose of Tdap instead of a Td booster if they have completed the recommended childhood DTP/DTaP immunization series and have not received Td or Tdap. The preferred age for Tdap vaccination is 11-12 years. If they have already received a Td booster, it is recommended that there be an interval of at least 5 years before Tdap is administered to reduce the likelihood of local and systemic reactions. Detailed recommendations for the use of Tdap are available from the CDC. 
• Adults 19-64 years of age should receive a single dose of Tdap (ADACEL®) to replace a single dose of Td for booster immunization if their most recent tetanus toxoid-containing vaccine was 10 or more years earlier. Tdap may be given at an interval shorter than 10 years since the last tetanus toxoid-containing vaccine in order to protect against pertussis. Detailed recommendations for the use of Tdap are available from the CDC.

Who should not receive the vaccine? 

• Those with a history of a serious allergic reaction (such as anaphylaxis) to any of the vaccine components.
• Those with a history of encephalopathy (e.g. coma or prolonged seizures) not attributable to an identifiable cause within 7 days of administration of a vaccine with pertussis components.
• Pertussis vaccines (including the DTaP vaccine) are not currently recommended for children who are 7-9 years of age.
• Tdap is not recommended to be administered within 2 years after the most recent tetanus toxoid-containing vaccine.

People with the following conditions should discuss with their health care professional whether they should receive DTaP vaccine: 

• Moderate or serious reaction after receiving DTP or DTaP in the past
• Seizure or have a parent or sibling who has had a seizure 
• Brain problem that is unstable or getting worse 
• People who are moderately or severely ill should consult with their physician before receiving any vaccine.

This vaccine is recommended by:

• Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention
• American Academy of Pediatrics
• American Academy of Family Physicians

The complete childhood immunization schedule can be found at:
www.cdc.gov/nip/recs/child-schedule.PDF

Dose Schedule

The DTaP vaccine—or DTaP, hepatitis B, and inactivated polio vaccines (Pediarix^TM1 , GlaxoSmithKline)—is given to most children at two, four, and six months of age.  Pediarix^TM can only be given for the first three doses a child receives.

A fourth dose of DTaP—or DTaP and Hib conjugate vaccine (TriHIBit®, Aventis Pasteur)—is given between 15 and 18 months, and a fifth dose is given at age four to six years.  If the fourth dose was given after age four years, then no fifth dose is needed.  TriHIBit® can only be given for these booster doses, not for the initial three doses.

Receiving combination vaccines from different manufacturers, which may include different component vaccines, can make the dose schedule more complex.  However, since giving combination vaccines means fewer shots overall for a child, healthcare providers will usually choose to administer them.  Healthcare professionals should attempt to select vaccines for their patients, especially children who have been seen by other practices, based on what they have already been given. 

Children younger than age seven who should not receive the pertussis vaccine should receive the DT (diphtheria-tetanus) vaccine. Between the ages of seven and nine, Td (tetanus-diphtheria), which contains the same amount of tetanus vaccine as in DTaP or DT, but contains much less diphtheria toxoid, is given to protect against tetanus and diphtheria.

The Td vaccine is given to unimmunized children age seven to nine years of age instead of DTaP (or any combination vaccine that includes a pertussis component) because there is no pertussis-containing vaccine licensed for this age group. Two doses are given one to two months apart, and a third dose should be given 6 to 12 months after the second dose.

At age 11-12 years, a booster shot of tetanus-diphtheria-acellular pertussis (Tdap) is needed. It should be given no later than 16 years of age. Every 10 years thereafter, a booster of Td is needed to maintain protection against diphtheria and tetanus.

One booster dose of Tdap is recommended for adults to replace a Td booster. Every 10 years thereafter, a booster of Td is needed to maintain protection against diphtheria and tetanus.

Effectiveness of the Vaccine

The DTaP vaccine is 95% effective in preventing all three diseases that it immunizes against--diphtheria, tetanus and pertussis. It is 59-89% effective in preventing pertussis, while the protection rates for diphtheria and tetanus are higher. Pertussis occasionally occurs in children who have received the pertussis immunization, but it is less severe and has fewer complications.

Known Side Effects

The DTP vaccine is no longer recommended in the United States. DTaP is now recommended because the rate of serious reactions to the DTaP vaccine is lower than with DTP; however, if a person has had a serious adverse reaction related to DTP, they should not be given DTaP.

Half of those vaccinated with DTaP will experience no side effects at all. About half of those vaccinated will experience mild reactions such as soreness where the shot was given, fever, fussiness, reduced appetite, tiredness, or vomiting. Some children may experience a temporary swelling of the arm or leg where DTaP was given; this reaction is more common after the fifth dose of DTaP.

In rare cases (about 100 children out of 10,000 shots given, or about 1%) children have moderate reactions such as prolonged crying, fever of 105 degrees or higher, seizure, or the child becoming limp, pale, and less alert.

In very rare cases (less than 1 out of every 10,000 shots given, or about .003%) children have serious reactions such as breathing difficulty, shock, or severe brain reaction (brain inflammation, long seizure, coma or lowered consciousness). These adverse reactions are usually due to the vaccine's pertussis component; therefore, doctors advise that infants and children who experience these adverse reactions to DTaP should receive DT for each of the remaining doses in the primary series.

Studies have shown that children who receive the Hib vaccine in combination with or at the same time as the DTaP vaccine are no more likely to experience side effects than children who only receive the DTaP vaccine.

Related Issues

Outbreaks of pertussis occur frequently when immunization levels fall. The following articles provide more information:

• Rohani P, Earn D, and Grenfell BT. (2000). Impact of immunisation on pertussis transmission in England and Wales (Research Letter). Lancet, 355 (9200), 285. 
• Gangarosa EJ, Galozoka AM, Wolfe CR, Phillips LM, Gangarosa RE, and Chen RT. (1998). Impact of anti-vaccine movements on pertussis control: The untold story. Lancet, 351, 356-361.

Questions about the relationship between the DTP vaccine and Sudden Infant Death Syndrome (SIDS) have arisen. Scientific investigations have shown no causal relationship between the DTP or DTaP vaccines and Sudden Infant Death Syndrome (SIDS).

For more information, see:
www.cdc.gov/nip/vacsafe/concerns/SIDS/default.htm

Key References and Sources of Additional Information

• American Academy of Pediatrics, Committee on Infectious Diseases. (2000). Red Book: Report of the Committee on Infectious Diseases (25th ed.). Elk Grove Village, IL: Author.
• Atkinson W, Wolfe C, Humiston S, and Nelson R (Eds.). (2000). Pertussis. In Epidemiology and prevention of vaccine-preventable diseases. (The Pink Book). (6th ed.). Atlanta: Centers for Disease Control and Prevention. Available on-line: http://www.cdc.gov/nip/publications/pink/pert.pdf.
• Centers for Disease Control and Prevention (CDC). (1991). Diphtheria, tetanus, and pertussis: Recommendations for vaccine use and other preventive measures: Recommendations of the Immunization Practices Advisory Committee (ACIP). Morbidity and Mortality Weekly Report (MMWR), 40(RR-10), 1-28.
• CDC. (1997). Vaccine Information Statement (VIS). Available on-line: www.cdc.gov/nip/publications/VIS/vis-dtp.pdf.
• CDC. (1997). Pertussis vaccination: Use of acellular pertussis vaccines among infants and young children: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR, 46(RR-7),1-25.
• CDC. (2000). Recommended childhood immunization schedule--United States, January-December, 2001 (Approved by the ACIP, AAP, and AAFP). MMWR, 49(2), 35-38, 47.
• CDC, National Immunization Program. (2000). Vaccine-preventable childhood diseases--Pertussis. Available on-line: www.cdc.gov/nip/diseases/child-vpd.htm.
• Combination Vaccines for Childhood Immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP), The American Academy of Pediatrics (AAP), and the American Academy of Family Physicians (AAFP). (1999). Pediatrics, 103(5). Available online: www.cdc.gov/mmwr/preview/mmwrhtml/rr4805a1.htm.
• Food and Drug Administration. (2002). Product approval information – Licensing action. Available online: www.fda.gov/cber/products/dtapsmi121302.htm.
• Halperin S, Smith B, Russell M, et al. (2000). Adult formulation of a five component acellular pertussis vaccine combined with diphtheria and tetanus toxoids and inactivated poliovirus vaccine is safe and immunogenic in adolescents and adults. Pediatric Infectious Disease Journal, 19(4), 276-83.
• Humiston SG and Good C. (2000). Vaccinating your child: Questions and answers for the concerned parent. Atlanta: Peachtree Publishers.
• Nguyen NN, He Q, Ramalho A, et al. (1999). Acellular vaccines containing reduced quantities of pertussis antigens as a booster in adolescents. Pediatrics, 104(6), 1-6.
• Offit PA and Bell LM. (1999). Vaccines: What every parent should know (revised edition). New York: IDG Books. 
• Pichichero M, Edwards K, Anderson EL, et al. (2000). Safety and immunogenicity of six acellular pertussis vaccines and one whole-cell pertussis vaccine given as a fifth dose in four- to six year-old children. Pediatrics, 100(1), 1-8.

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