How Long Does Immunity Last After Routine Childhood Immunization with Pertussis Vaccine?

Patient Presentation
A 2.5 month-old male came to clinic with persistent cough of 2 weeks duration.
He started with a runny nose and then began coughing. The cough has been getting worse especially in the past 2-3 days where he is now having post-tussive emesis of his feeds.
Since last night his parents have noticed more rapid breathing and he is slower feeding also. They have not noticed any apnea, color changes, tracheal tugging or intercostal retractions. They state that “his belly keeps going up and down more though.”The coughing seems to be all the time and not in groups of coughs.
He has not had a fever, rash, or diarrhea. He did have sneezing intermittently.
The past medical history showed that he was born full-term and went home on time. He has not had his two month health maintenance visit.
The social history showed that he lives with his parents, two preschool age siblings who are immunized, and a high-school age cousin who was immunized in 2004. The cousin has been coughing for about 4 weeks and there is known pertussis in his high school.
The pertinent physical exam shows a tachypneic infant with a respiratory rate of 70 breaths/minute. He is afebrile, his oxygen saturation is 89% on room air and decreases with coughing episodes.
He has moderate subcostal retractions and minor nasal flaring and tracheal tugging. He is not cyanotic and is well-perfused.
HEENT shows no rhinorrhea. Lung examination has no rubs, rales or rhonchi. He seems to have generalized decreased breath sounds.
The rest of his examination was normal.
The differential diagnosis of his respiratory distress includes pertussis, pneumonia, sepsis, late onset perinatally acquired infections, and various viral syndromes.
It was less likely that this is congenital abnormality because of the onset and lack of previous symptoms.
The patient’s clinical course was that he was admitted to the hospital with a diagnosis of presumed pertussis.
The laboratory evaluation showed a white blood cell count of 10.3 with 70% lymphocytes.
Blood cultures, and a nasal swab for respiratory pathogens including pertussis antigen detection were sent.
The radiologic evaluation was normal.
He was given supplemental oxygen and monitored for apnea. He was also given occasional albuterol for respiratory distress and wheezing which gave some relief.
His cousin also had a nasal swab sent for pertussis antigen detection and was begun on azithromycin for presumed pertussis. He had received Td for his 11-12 year vaccinations but as 5 years had not elapsed since that time and he was not in contact with other high risk individuals, he was not re-immunized with Tdap that was currently available.
His family members were given antibiotics as well to treat unrecognized disease and to limit transmission. Public health was contacted for community disease management once pertussis was confirmed.
On day 2 of admission, the pertussis antigen testing was positive and the other cultures remained negative throughout the admission.
He slowly weaned off of his oxygen by day 4 and he had no apneic episodes in the hospital.
He received his 2 month vaccinations including DTaP prior to leaving the hospital.

Figure 56 – PA and lateral radiographs of the chest show the heart size and pulmonary vasculature to be unremarkable and the lungs to be clear from infiltrates and effusions. There is no evidence of the classic “shaggy heart” appearance of interstial infiltrates classically described in pertussis pneumonia.

Bordetella pertussis is pleomorphic gram-negative bacillus that is transmitted by aerosolized droplets between humans which are the only known host.
The incubation period is from 5-21 days with an average of 7-10 days. It is most contagious during the catarrhal stage and first 2 weeks of cough. .
Isolation is for 5 days after treatment is started or until 3 weeks after cough has started that has not received treatment.
It occurs cyclically within communities with 3-5 year cycling but because of travel may occur in any community at any time.

The catarrhal stage occurs from the beginning of symptoms up to 2-3 weeks of coughing and has symptoms of rhinorrhea, low grade fever, cough, sore throat, headache and fatigue.
The paroxysmal stage occurs from after the catarrhal stage to weeks later and has progressive proxysmalcough that may be preceeded by an inspiratory whoop. Emesis is common.
Infants often do not have the whoop sound and may have apnea, gagging or gasping. The whooping sound may or may not be present at any age.
The convalescent stage occurs from weeks to months and has a gradual improvement of symptoms. Duration of classic pertussis is 6-10 weeks.

Complications include encephalopathy (0.5%), incontinence, pneumonia (22%), rib fractures, seizures (2%), syncope, sleep disturbance, and death. Particularly in infants < 2 months there is a 1% risk of death. This is markedly decreased after 2 months.
Diagnostic testing is available for pertussis by culturing on special culture mediums. Unfortunately this takes 10-14 days for results. DNA polymerase chain reaction testing or IgG antibody testing is also available.

Prolonged cough can also be seen with Mycoplasma pneumoniae, Chlamydia trachomatis, Chlamydophila pneumoniae, Bordetella bronchiseptica, Bordetella parapertussis, Bordetella holmseii , adenovirus, respiratory syncytial virus and some other respiratory viruses.

Infants less than 6 months are often hospitalized because of the risk of apnea. The infants also need to have their ability to self-rescue after the paroxysms of cough, and ability to remain hydrated.
Antibiotics if given during the catarrhal phase may improve the disease. After the paroxysmal stage, they are used to prevent the spread of the organism but have no effect on the disease.
Persons who are unimmunized or underimmunized should receive vaccination as soon as possible.
Penicillins and cephalosporins are not effective against pertussis.
Recommended treatment or prophylaxis is with erythromycin, azithromycin or clarithromycin. Trimethoprim-sulfa is used as an alternative.
Because of the risk of idiopathic hypertrophic pyloric stenosis associated with erythromycin, azithromycin is the preferred drug for infants < 6 months.

Learning Point
It is highly infectious with ~80% of household contacts acquiring infection regardless of immunization status.
Infection itself nor immunization provides life-long immunity. Immunity after receiving early childhood immunization (e.g. infant, preschool, kindergarten) wanes after ~ 10 years.

Tdap became available for persons 11-64 years of age since the spring of 2005.
Boosterix® by GlaxoSmithKline Biologicals is recommended for routine immunization for ages 11-18 years (preferrably at the 11-12 year vaccines).
Adacel® by Sanofi Pasteur is recommended for routine immunization for one dose in persons ages 11-64 years.

Questions for Further Discussion
1. What are the differences in the side effect profile for accelular or whole-cell pertussis vaccine?
2. What other diseases besides pertussis should be reported to the Department of Public Health?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at MedlinePlus for these topics: Whooping Cough and Immunization.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

American Academy of Pediatrics. Pertussis, In Pickering LD, Baker CJ, Long SS, McMillan JA, eds. Red Book: 2006 Report of the Committee on Infectious Diseases. 27th edit. Elk Grove Village, IL: American Academy of Pediatrics; 2006;498-520.

Centers for Disease Control. Guidelines for the Control of Pertussis Outbreaks.
Available from the Internet at (rev. 2006, cited 11/16/07).

Altunaiji S, Kukuruzovic R, Curtis N, Massie J. Antibiotics for whooping cough (pertussis).Cochrane Database Syst Rev. 2007 Jul 18;(3):CD004404.
Available from the Internet at (rev. 7/18/2007, cited 11/16/2007).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement

    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.
    26. Partnering with health care managers and health care providers to assess, coordinate, and improve health care and how these activities can affect system performance are known.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    December 31, 2007