Vaccine Information

Entry last updated: February 25, 2004

- 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 175,000 cases of pertussis were reported in the United States each year, with approximately 8,000 deaths caused by the disease. Today, there are about 7,000 cases of pertussis and 10 deaths annually. Worldwide, there are an estimated 300,000 annual deaths due to pertussis.

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

Vaccines containing the whole cell pertussis component (DTP) are no longer recommended for use in the United States and are not listed here.

Product Name: Tripedia� (DTaP)
Manufacturer: Aventis 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: Aventis 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: Aventis Pasteur
Year Licensed: 2002

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

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.

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.

Who should not receive the vaccine?�

• Pertussis vaccines (including the DTaP vaccine) are not currently recommended for children after they reach their seventh birthday because pertussis is not a life-threatening disease in older children and adults, though they often spread the disease to infants and young children. Studies are currently being undertaken to determine the safety and efficacy of DTaP when given after age six; preliminary data suggests that the vaccine is safe and effective in adolescents and adults.

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.�

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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