If you’ve had Pertussis yourself, that means you also have naturally-acquired antibodies to pertussis, which would have been passed to your baby through the placenta in utero.


 In the Swedish study that initially determined the safety and efficacy of the DTaP vaccine, they tested a subset of babies before giving them any doses of DTaP and found “some prevaccination samples contained high levels of maternal antibodies against pertussis.” Obviously, some of these babies didn’t need the vaccine. It’s documented from other research on other diseases and vaccines that maternal antibodies prevent vaccines from working the way they are intended to. The antibodies themselves detect the vaccine and get rid of it before the immune system can respond. Meaning, vaccinating a young infant who very likely has maternal antibodies already is pointless.

Maternal antibodies are known to dissipate from around 6-12 months after birth. After 6 months of age pertussis is way less of a concern. Most deaths have been in infants younger than 4 months old.

The Swedish study Highlights:

1) only healthy infants were enrolled in the study–infants with any history of chronic illness, seizure, immunosuppressant, etc. were excluded, but in practice, all infants receive the vaccine. So it’s not safe or ethical to test a vaccine in a child with impaired health status, but those kids get the vaccine later anyway.


2) Children were contraindicated for receiving the vaccine if they had a fever or had received another vaccine recently. Children get shots regardless of fevers or other vaccines received.

3) Children were contraindicated for further doses and dropped from the study if they  had an adverse event such as persistent crying, high fever, shock, etc. This was a 2-year study to determine long-term safety and efficacy of a 3-shot series, but the children, who reacted worst, and soonest, are not represented in the final results.
4) The old whole-cell version of DPT, given until about 1997 in the US, was bad.  It had a high rate of serious reactions, and these researchers calculated its effectiveness at only around 48%. But for the previous 20 years, parents in the US were being told their children must have this vaccine. The real truth about a particular vaccine being kind of dangerous and ineffective doesn’t come out until the pharmaceuticals decide they have something better.

In 1993-the JAMA published reports of adverse reactions , including death , following pertussis vaccines. Journal of American Medical Association 101(3) (1993) pp 187-88. See also:

  • Cherry JD et al (1993). Pertussis immunization and characteristics related to first seizures in infants and children. J Pediatr 122(6):900-3 1993. Department of Pediatrics, University of California Los Angeles School of Medicine.
  • Blumberg DA, et al.    Severe reactions associated with diphtheria-tetanus-pertussis vaccine: detailed study of children with seizures, hypotonic-hyporesponsive episodes, high fevers, and persistent crying. Pediatrics. 1993 Jun;91(6):1158-65. PMID: 8502521; UI: 93275702.  
  • Nielsen AO, et al.    [Aluminum allergy caused by DTP vaccine]. Ugeskr Laeger. 1992 Jun 29;154(27):1900-1. Danish. PMID: 1509548; UI: 92376915.
  • Griffin MR et al (1990). Risk of seizures and encephalopathy after immunization with the diphtheria-tetanus-pertussis vaccine. JAMA 263(12):1641-5 1990. Department of Preventive Medicine, Vanderbilt University School of Medicine, Nashville, Tenn 37232-2637. Miller D, et al (1993). Pertussis immunisation and serious acute neurological illnesses in children. BMJ. 1993 Nov 6;307(6913):1171-6. PMID: 7504540; UI: 94072962.

In 1948 Pediatrics published reports of irreparable damage and death following pertussis vaccine inoculations. Pediatrics, 1(4), (1948) pp. 437-457

In 1950 Lancet published a report describing severe neurological complications, mental retardation and paralysis, following a combined pertussis-diphtheria vaccine.
Lancet , (March 25, 1950) pp537-39. See also: Medline

The British Medical Journal published several studies showing a connection between the polio , diphtheria ,measles , tetanus ,and smallpox vaccines , and the development of Multiple Sclerosis several years later. British Medical Journal , Vol.2,(1967) pp 210-213.


 A study in The Journal of Infectious Diseases confirms that the DPT injections induce polio. (The oral polio shot is given at the same time and the only known cases of polio have come from the shot since 1980).  The Journal of Infectious Diseases (March 1992) pp 444-449. Source Neil Z. Miller’s Vaccines : Theory vs. Reality.


The pertussis vaccine is used in animal experiments to create allergies in order to test allergy medicine.


New Zealand -Based on a study in VACCINE, decided to use the acellular vaccine which tested the most effective, which is the five component one, which supposedly had a 78% effectiveness rate. In the final year report from the health department public surveillance, they admitted that in reality it only has a 33% “effective” immunization rate.   (Source: Theor Biol. 2003 Sep 21;224(2):269-75. Estimation of effective vaccination rate: pertussis in New Zealand as a case study.
Korobeinikov A, Maini PK, Walker WJ. Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford, UK.)


In some cases vaccination is unreliable. For example vaccination against pertussis has comparatively high level of primary and secondary failures. To evaluate efficiency of vaccination we introduce the idea of effective vaccination rate and suggest an approach to estimate it. We consider pertussis in New Zealand as a case study. The results indicate that the level of immunity failure for pertussis is considerably higher than was anticipated.

“The obtained figures indicate that in New Zealand the effective vaccination rate against pertussis is lower than 50%, and perhaps even as low as 33% of the population. These figures contradict the medical statistics, which claim that more than 80% of the newborns in New Zealand are vaccinated against pertussis (Turner et al., 2000). This contradiction is due to the mentioned unreliability of the available vaccine.”

There are a lot of VICP death cases. Some are compensated, but more are dismissed because the deaths either did not fit the government’s onset timeline or rigid causation and/or doctors refused to testify, etc. Many deaths were initially ruled as SIDS by the coroner. When you look at the bacteriology, immunology, virology and toxicology reports, they point to clear indicators.


DTaP is effective in preventing Pertussis?

That depends on what you mean by effective. An effective vaccine would require only one dose to achieve immunity. The DTaP requires that you get up to five doses for an 80% chance at immunity. That’s the lowest efficacy of any vaccine on the market. And despite high vaccine coverage, the incidence of pertussis is increasing.

DTaP contains aluminum, a potent neurotoxin that enters the brain when injected as a vaccine adjuvant. The amount of aluminum injected in a single vaccine dose is sufficient to alter gene expression in the brain. These are things that will manifest adversely in the long-term: they are not included in the parameters of the vaccine safety studies that monitor only short-term effects.

There isn’t much data on the efficacy and protection from one or two doses of DTaP. Pertussis vaccine trials are difficult to do. Virtually everyone who has looked at this issue uses 3 doses as the benchmark. We know that if you get 3 doses into a child, you are looking at 80%-85% efficacy.
Information on efficacy studies, etc.


 Since 1991, seven studies conducted in Europe and Africa have evaluated the efficacy of eight DTaP vaccines administered to infants. The vaccines, produced by different manufacturers, contained a varying number and quantity of antigens. The derivation and formulation of the individual antigens also varied among vaccines (Table_1). Four doses of vaccine were administered in one study (Wyeth-Lederle Vaccines and Pediatrics, ACEL-IMUNE{Registered} package insert); the other six studies involved three doses (14,15,23-25). These studies also differed in other ways (Table_2)


The efficacy of three doses of acellular pertussis vaccines in preventing moderate to severe pertussis disease was within the range expected for most whole-cell DTP vaccines. Point estimates of efficacy ranged from 59% to 89%.


  This report supplements the statement from CDC’s Advisory Committee on Immunization Practices regarding use of acellular pertussis vaccines and summarizes data regarding reactogenicity of acellular pertussis vaccines when administered as the fourth and fifth consecutive doses. Increases in the frequency and magnitude of local reactions at the injection site with increasing dose number have occurred for all currently licensed DTaP vaccines. Extensive swelling of the injected limb, sometimes involving the entire thigh or upper arm, after receipt of the fourth and fifth doses of DTaP vaccines has been demonstrated for multiple products from different manufacturers.


 There are 3 types of DTaP:








 DTaP combo vaccines:





 Contradictions to all:

If the child is sick with something more serious than a mild cold, DTaP may be delayed until the child is better.


If the child has had any of the following after an earlier DTaP, consult with the health care provider before the child receives another injection of the vaccine:


  • seizures within 3 to 7 days after injection

  • any serious brain problem within 7 days after injection

  • worsening of seizures or other brain problem (at any time)

  • mouth, throat, or face swelling (serious allergy) within a few hours after injection

  • difficulty breathing (serious allergy) within a few hours after injection

  • temperature of 105 degrees F or higher within 2 days after injection

  • shock or collapse within 2 days after injection

  • persistent, uncontrolled crying that lasts for more than 3 hours at a time within 2 days after injection


 What is the difference between DTP and DTaP:


The DTaP is made by removing many of the poisons (toxins) found in the whole-cell B.Pertussis bacteria that are used in the DTP vaccine. What remains are just a few components of the bacteria rather than the whole organisms. These components are detoxified using formaldehyde, and then thimerosal and aluminum are added. This acelluar, rather than whole cell, version of the pertussis vaccine is then combined with the DT vaccine to create DtaP. Removing these toxins from Pertussis also significantly reduces but does not eliminate the number and potency of the adverse effects associated with the vaccine. (Source Stephanie Cave 2001)


*note- Thimerosal content to date in the US –

Thimerosal has been reduced to traces; however, some of the older vaccines may be on the shelves and used until as late as 2007.


 A Not-so-Perfect Vaccine :

The Diphtheria, Tetanus and Acellular Pertussis Vaccine: An Investigation


 The Disease


Pertussis or Whooping Cough is an acute infectious disease caused by Bordetella pertussis.  The disease has been described for centuries; the organism was first isolated in 1906. Whooping cough is transmitted through the respiratory route usually by droplets of secretions.


The incubation period is usually 7 to 14 days but may be as short as 5 days and as long as 21 days. The disease evolves in three phases. Patients are most contagious during the initial catarrhal stage consisting usually of minor cold symptoms and a slight nocturnal cough. During the paroxysmal stage, which may last for several weeks, the patient has the more characteristic coughing spells, which culminate in an inspiratory whoop and are often followed by vomiting. There is usually a marked leucocytosis (increased white count) and lymphocytosis (increased lymphocyte count). In newborns and young infants, whooping cough may present as apnea and cyanotic spells. During the convalescent stage, the paroxysms subside; the patient coughs less and clinical improvement becomes evident.


Erythromycin is the antibiotic of choice for the treatment of whooping cough. If given early, it shortens the course of the illness and reduces its severity. Because it also eradicates the organism from the secretions, it decreases spread and communicability.

Erythromycin or trimeththoprim-sulfamethoxazole prophylaxis is of value for close contacts and is recommended regardless of vaccination status.


 The following statements are true about whooping cough and whooping cough vaccination


  1. The incidence of whooping cough in the United States had decreased before the introduction of the pertussis vaccine.

  2. It has continued to decrease since the vaccine has been in use.

  3. Whooping cough may be a serious and potentially fatal illness in young and vulnerable infants. 

  4. DTP vaccination has been associated with many severe and permanent adverse events including encephalopathy, brain damage, seizures, and even death. The reactions have been attributed to the pertussis component.

The DTAP Vaccine


The Federal Drug Administration (FDA) approved the use of DTAP for booster doses in 1991 and for all doses in 1996. All DTP and DTAP products used in the US contained thimerosal, a mercury derivative. In 1999, the AAP and FDA recommended that thimerosal be removed from pediatric vaccines. 


Several acellular pertussis vaccines were developed and licensed in the United States. They contained different purified inactivated components of B. pertussis in varying concentrations and were always combined with diphtheria and tetanus toxoids. No single antigen pertussis vaccine has been available commercially for sometime. According to the CDC “Contraindications to further vaccination with DTP or DTAP are severe allergic reactions to a prior dose of vaccine or vaccine component and encephalopathy, not due to another identifiable cause, within 7 days of vaccination…Certain infrequent adverse events following pertussis vaccination will generally contraindicate subsequent doses of pertussis vaccine. These adverse events are: Temperature to 105°F within 48 hours, not due to another identifieable cause, Collapse or shock-like state (hypotensive-hyporesponsive episode) within 48 hours, Persistent, inconsolable crying lasting 3 hours or more and Convulsions with or without fever occurring within 3 days…Acellular pertussis vaccine should not be substituted in children who have a valid contraindication to whole cell pertussis vaccine. If a valid contraindication or precaution exists, DT should be used for the remaining doses on the schedule.” (9)


The manufacturer of one of the still available DTAP products lists the same contraindications as those of the CDC; specifically that encephalopathy (not due to other identifiable causes) within 7 days of vaccination is a contraindication for further pertussis vaccination. According to that manufacturer, encephalopathy consists of major alterations of consciousness, unresponsiveness, generalized or focal seizures that persist for more than a few hours and failure to recover within a few hours. (10)


Interestingly, and most unfortunately, as shown in the box below, filing for “on-table” vaccine compensation is allowed only if encephalopathy has occurred in the 72 hours following vaccination with a pertussis antigen-containing vaccine (11)



When DTP was used exclusively, many studies were published regularly to convince physicians and parents that the vaccine was quite safe. The fact is that the DTP vaccine was not safe and that it had to be replaced by the DTAP vaccine.

Now, the CDC and vaccine manufacturers consistently downplay the side effects of DTAP vaccination. Indeed, though minor reactions following DTAP are fewer than with DTP, more serious reactions occur in rather disturbing numbers. This is supported by a report that was issued by a committee of US Scientists and published in 1987 in the Journal of the American Medical Society (JAMA). In “Acellular and whole-cell pertussis vaccines in Japan. Report of a visit by US scientists”, the authors stated:


“Since the introduction of acellular pertussis vaccines in Japan late in 1981, more than 20 million doses have been administered, mostly to children 2 years of age and older. Clinical studies indicate that mild local and febrile reactions are less frequent after administration of acellular pertussis vaccines than after whole-cell vaccines. Serious adverse events with sequelae occurred in 2-year-old children at approximately the same low rate during the period 1975 through August 1981, when whole-cell vaccines were used, and during August 1981 through 1984, when acellular vaccines were used exclusively.” 

Clearly multiple reports of serious DTAP-associated reactions have been filed with VAERS. Again, one must keep in mind that less than 10% of adverse events after vaccination are ever reported.


Delaying DPT Vaccination May Reduce Incidence of Childhood Asthma 

Medscape News. Laurie Barclay, MD. April 14, 2008. J Allergy Clin Immunol. 2008;121:626-631.


Childhood asthma is reduced by half when the first dose of diphtheria, pertussis, and tetanus (DPT) is delayed by more than 2 months vs given during the recommended period, according to the results of a retrospective longitudinal study reported in the March issue of the Journal of Allergy & Clinical Immunology.

“Early childhood immunizations have been viewed as promoters of asthma development by stimulating a TH2-type immune response or decreasing microbial pressure, which shifts the balance between TH1 and TH2 immunity,” write Kara L. McDonald, MSc, from the University of Manitoba in Winnipeg, Manitoba, Canada, and colleagues. “Differing time schedules for childhood immunizations may explain the discrepant findings of an association with asthma reported in observational studies. This research was undertaken to determine whether timing of diphtheria, pertussis, tetanus (DPT) immunization has an effect on the development of childhood asthma by age 7 years.”

The investigators analyzed data from the complete immunization and healthcare records of a cohort of children born in Manitoba in 1995, from birth until age 7 years. Using multivariable logistic regression, they computed the adjusted odds ratio for asthma at age 7 years according to the timing of DPT immunization.

Among 11,531 children who received at least 4 doses of DPT, the risk for asthma was halved in children in whom administration of the first dose of DPT was delayed by more than 2 months. For children with delays in administration of all 3 doses, the likelihood of asthma was 0.39 (95% confidence interval [CI], 0.18 – 0.86).

“We found a negative association between delay in administration of the first dose of whole-cell DPT immunization in childhood and the development of asthma; the association was greater with delays in all of the first 3 doses,” the study authors write. “The mechanism for this phenomenon requires further research.”

Limitations of this study include possible ascertainment bias; findings not yet confirmed with the diphtheria, acellular pertussis, tetanus (DaPT) vaccine; and inability to refute the issue of early-life infections as an explanation for the association between delayed immunization and protection against the development of asthma.

“Further study is vital to gain a detailed understanding of the relationship between vaccination and allergic disease, because a perception that vaccination is harmful may have an adverse effect on the effectiveness of immunization programs,” the study authors conclude.

The Canadian Institutes of Health Research supported this study. Some of the authors have disclosed various financial relationships with the Western Regional Training Center for Health Services Research, the National Training Program in Allergy and Asthma, the Canadian Institutes of Health Research, Allergen, and/or Novartis.

Epidemiologic evidence linking DPT immunizations to childhood asthma is inconsistent. Some studies show an increased or decreased risk of developing asthma, whereas others show no association. This study assessed whether timing of DPT vaccination affects the risk of developing childhood asthma by age 7 years.



Treatment of Pertussis

Vaccinating yourself and your children will not prevent your new baby from getting it. The vaccine has one of the lowest efficacy rates and you can still spread the germs that cause it even if you are not currently infected. Pertussis isn’t as deadly for infants as you are led to believe it is. When they say the mortality rate for pertussis in infants under 6 months is 0.5%, or 1 out of every 200, that is including all the infants who are formula fed, who live with smokers, who have health problems, etc. There’s a big difference between a baby in those circumstances and a breastfed baby living in a healthy environment.

Vitamin C in the treatment of Pertussis:

 Vitamin C, Infectious Diseases, & Toxins by Thomas E. Levy, MD, JD

pg. 116: Otani (1936) found that pertussis bacteria seemed to be especially susceptible to the effects of vitamin C in the test tube, with high enough dose having a killing, bactericidal effect. It was also demonstrated that a culture of pertussis bacteria in which vitamin C had been added possessed a “strongly reduced” infectivity in test animals.


Pg. 118: The bacteria causing pertussis can be killed in culture by vitamin C, and the effects of the pertussis toxin also appear to be lessened by vitamin C…

…adequate regular dosing of vitamin C should prevent pertussis from ever being contracted.



The primary function of Vitamin C is not to kill the bacteria. It does inhibit them, but the main action in any toxin-mediated disease is to neutralize the toxin, and to support the liver so that when the liver is reducing the amount of endotoxin,  the liver works much more efficiently.   It does not stop the disease. It modifies it, and makes the cough milder.


 Vitamin C also puts petrol into the tank of macrophages and phagocytes, and in vitro increases their activity levels. Therefore, in the body, it should increase the effectiveness of the immune system in general, as well as dealing with the specifics of the toxin issue, and inhibiting the bacteria itself.

You can dissolve Vitamin C (sodium ascorbate powder) in breast milk. You can use a dropper or dribble it into the inside of the cheek. Don’t squirt it in their mouths in case they inhale it and that would trigger the vagus nerve.


The Bowl tolerance Method:


You give your child a small dose (1/4 tsp) of the C in liquid you choose every half hour to an hour until they have a loose stool. The amount of Vitamin C it took them to get there is just past tolerance. You then cut back 1/4 tsp and that’s saturation. Each person has a different level. Everyone will tolerate more when we are sick.


 For Breast feeding Mothers:


It takes about 8 hours for the vitamin C you take to get through to the breast milk. A Pinch is about 250 mg. If I thought my child was really sick, then I would calculate Vitamin C for her at 375 mg/kg of body weight, and give that over waking hours, and perhaps a larger dose given just before bedtime.


 Also, a good vitamin and mineral supplement to help your body deal with emotional stress, Halibut Liver oil, and about 10 grams of vitamin C spread out over your waking hours. You can use powdered sodium ascorbate, and mix it (10 grams = 2 heaped teaspoons) in with 1.25 liters of water in a water bottle. Drink it gradually throughout the day.


The Progression:


 First they get a cold. Then after a week, they start the odd cough, and after about two weeks, the cough gets stronger. At the end of the cough, which might be a month later, they will bring up globs of fairly thick mucus. This is because it pools down to the bottom of the lungs because the toxin from the bacteria has cut off most of the hairs in the bronchial that sweeps the mucus up and around. The cough sounds dry and that’s because the mucus membranes aren’t being kept as moist as they normally are. Most children, as long as they are getting that mucus up, and do not pool it (where secondary bacterial infections can set it) only have problems when they are coughing. The rest of the time they act normal. Coughing can be provoked by touching the back of the tongue, eating food, or running around. Towards the end of the illness, if they get worked up and tense up, it triggers the cough.


 To help a baby during the cough:


Turn the baby round, with its back to yours. Split your legs, so the baby is supported around the tummy but the legs are straight down. Your hands make a net around the baby’s ribcage and tummy, and when the baby coughs, lean forward slightly and use the hands as a very gentle net so that the baby has something for the tummy to push against. They haven’t learned to control their abdominal muscles to get an efficient cough yet, so t hands make it much easier for them. If it is whooping cough, then you will get a thick clear mucus glob ejected. If it is whooping cough, then the cough will become more regular.


The cough is caused by the bacteria adhering to the bronchial walls, and secreting a toxin, which cuts off the cilia (hairs) in the bronchials. These hairs sweep the mucus up and spread throughout the throat. The bronchial hairs move the mucus around all the time, so that it replaces, and at the same time, gets rid of any pathogens. This mucus is part of the innate immune system. It is linked to the BALT (Bronchial associated lymphatic tissue). You must keep the mucus moving. Whooping cough cuts off the hairs, and tries to stops the mucus from  moving. As long as you keep the mucus moving, your baby should not get a secondary infection.

The other thing the toxin can do is get into the blood-stream, and irritate the body. If the baby’s immune system is not good then this toxin can get to the brain as well. If the mucus is not gotten out, bacteria will grow and cause a secondary bacterial infection, which they will want to treat with antibiotics. Whooping cough in rare cases can cause long-lasting bronchial problems. However, that is if you treat it the way the doctors do, with antibiotics. Antibiotics do not deal with the pooling mucus, or manage it, or deal with the toxin. If you keep the mucus moving there should be nor further problems other than the cough itself.

Whooping cough will last approximately 100 days, but mainly as an irritating annoyance only. After a bout of whooping cough, for the next 6 – 9 months, any cold that the child gets, the child will start to whoop, or cough, the same way as they did with whooping cough. The reason for that is that it takes a long time for the hairs to grow back, and so any infection without proper hairs in the bronchials, will result in mucus pooling.
It is this mucus pooling that has to trigger a cough strong enough, to get the mucus from the bottom of the bronchials up to the top. If they are coughing until they are purple, then your doses of vitamin C are too small. Bump them right up to the level of 375 milligrams per kilo of body weight over the waking hours, as a starting dose. If your dose is right, within 8 hours there should be a two third reduction in the coughing.


Testing for Pertussis:

 This one is useless:

Isolation of B. pertussis by culture is 100% specific; however, sensitivity of culture varies because fastidious growth requirements make it difficult to transport and isolate the organism. Although the sensitivity of culture can reach 80%–90% under optimal conditions, in practice, sensitivity typically ranges from 30%–60% (57). The yield of B. pertussis from culture declines in specimens taken after 2 or more weeks of cough illness, after antimicrobial treatment, or after previous pertussis vaccination (58). Within 3 weeks after onset of cough, culture is only 1%–3% sensitive (59). Although B. pertussis can be isolated in culture as early as 72 hours after plating, it takes 1–2 weeks before a culture result can definitively be called negative (60). Culture is essential to isolate B. pertussis for antimicrobial susceptibility testing and for molecular subtyping of strains.  
Direct fluorescent antibody (DFA) tests provide rapid results (hours), but are generally less sensitive (sensitivity: 10%–50%) than culture. With use of monoclonal reagents, the specificity of DFA should generally be >90%; however, the interpretation of the test is subjective, and interpretation by an inexperienced microbiologist can result in lower specificity (61). Because of the limitations of DFA testing, CDC does not recommend its use.


The only Pertussis diagnostic tests that the CDC endorses are culture and Nasophyngeal PCR. Tests other than the PCR have a high false positive or false negative rating. However, many medical articles still say that there are no reliable correlates of protection (antibody test) for Pertussis.


Whooping cough cannot be correctly diagnosed without a nasopharyngeal swab because other pathogens like adenovirus can cause an identical syndrome, as can other bacteria, so the swab must be tested with the PCR (polymerase chain reaction) test.  

Doctors will give you Erythromycin, which does not shorten, or do anything to lessen the course of the disease. It can make babies irritable, bother the stomach, and suppress the immune system further. It can simply make the situation worse. There is no reason to use antibiotics, unless the mucus they spit up becomes green in color. Make sure the child drinks enough liquids, to keep the mucus as thin and easy to get up as possible.



Pertussis-Epidemiology and Transmission of Disease

Epidemiology and Transmission of Disease

Pertussis infection is unique to humans. There are no animal reservoirs, and the organism cannot survive for a prolonged period in the environment. Localized to the respiratory tract, the organism is transmitted primarily by aerosol droplets from an infected person to a susceptible one. The infection is highly contagious, with attack rates ranging from 50% to 100%. The highest attack rates occur among persons with exposure within 5 feet of a coughing patient.[5]

In the pre-vaccine era, pertussis was predominantly an infection of children aged 1 to 5 years, with maternal immunity providing passive protection during an infant’s first year of life. At that time, an average of 175,000 US cases were reported per year (incidence of approximately 150 cases per 100,000 population).[6] The incidence of disease declined steadily over the two decades after introduction of whole-cell pertussis vaccine, reaching an all-time low of just over 1000 reported cases in 1976.[7,8] Since then, the incidence of infection has continued to rise, with almost 26,000 cases reported to the CDC in 2004 (Figure 1).[9]


 Pertussis is the only vaccine-preventable disease on the rise in the US and it is severely underreported. CDC estimates that, at best, one-third of cases are believed to be reported to the CDC;[10] other estimates place the reported cases at 1 in 10 to 1 in 20 of the true incidence.[11] Although pertussis incidence remains highest among young infants, rates are also on the rise in adolescents and adults and there may be significant under-reporting in these age groups, especially those with mild or atypical infection.[7] Compared with surveillance data from 1994 to 1996, the pertussis incidence rate among adolescents and adults increased 62% and 60%, respectively, from 1997 to 2000.[7]

Increased incidence of pertussis in adolescents and adults relates to waning immunity and, likely, to a combination of previous underreporting and recent improvements in reporting processes. The longer the duration since vaccination, the higher the attack rate (Figure 2).[12] Data from a seroprevalence study by Cattaneo et al showed a peak in antibody titers at 4 to 6 years of age, coinciding with DTaP booster dosing, followed by a decline, and a second peak between 13 and 17 years of age.[13] Similar findings were documented by the National Health and Nutrition Examination Survey (NHANES), which reported a protracted decline interrupted by a peak in persons aged 40 to 45 years.[14] Since no pertussis-containing vaccine had been given past the age of 6 years, these spikes in adolescents and older persons clearly represent natural pertussis exposure. These persons not only represent potential cases, but a reservoir of disease that puts those most susceptible to significant morbidity and mortality (ie, those at the extremes of age) at risk of exposure.

Pertussis has been estimated to account for up to 17% of prolonged cough illness in adults.[15,16] Among adults with cough illness, the incidence of confirmed pertussis has been estimated at 170 to 630 cases per 100,000.[17,18] The rates among adolescents were almost 2-fold higher. Data from a prospective acellular pertussis vaccine efficacy trial (APERT) extrapolate the burden of pertussis to be nearly 1 million US cases annually in persons 15 years old.[11]

Given the large disease burden in adolescents and adults estimated by these studies, the limited number of confirmed cases of pertussis (defined in Table 1 ) in older children, adolescents, and adults is striking. A large proportion of these cases may be atypical and undiagnosed. However, according to recent data from Bisgard et al,[19] in cases where the source of pertussis was identifiable, adolescents and adults were the primary source of infection for 20% and 56%, respectively, of infants with pertussis.

Contact with infected adolescents and adults is a common source of B. pertussis infection in infants and unprotected, young children. Widespread silent transmission of pertussis within families has been reported.[20] In a study of risk factors for pertussis-related hospitalizations, siblings were the most common source (53%), followed by parents (20%), other relatives (12%), neighbors (8%), and day-care contacts (3%).[21] In a case-control study, infants of adolescent mothers (aged 15 to 19 years) were 6-fold more likely to contract pertussis, compared with infants of older mothers (aged 20 to 29 years).[22]

Details of the pathogenesis of pertussis infection have been extensively reviewed elsewhere.[23] In brief, the development of pertussis infection begins with entry of B. pertussis into the respiratory tract of a susceptible host. The organism produces adhesion and bacterial surface attachment factors that allow its attachment to cilia in the respiratory mucosa. Tracheal cytotoxin and other toxins are produced and released into the local environment, damaging the cilia and respiratory epithelium. These changes disturb clearance of pulmonary secretions and probably result in development of the coryza and cough observed during the catarrhal phase of the illness. Even as local damage increases, attracting host immune cells, the actions of additional toxins probably inhibit phagocyte functions, thereby protecting the proliferating organisms from clearance. In some cases, the proliferation of B. pertussis continues until organisms reach the alveoli, resulting in pneumonia.

Pertussis symptoms are nonspecific in nature, making the clinical diagnosis challenging. The type and severity of symptoms that develop are highly variable, as is the time frame over which they appear and resolve. Adolescents and adults, as well as those partially protected by pertussis vaccine, frequently have mild clinical disease (or even asymptomatic disease) that goes undiagnosed. Although illness may be milder in adolescents and adults, they are a reservoir of infection and may transmit whooping cough to unimmunized or partially immunized infants. Of great concern, health care providers often do not recognize the varied clinical presentations and do not consider a pertussis diagnosis in patients with chronic cough.[17] Furthermore, management of pertussis is complicated by the fact that infected persons are most contagious early in their illness, before they become symptomatic.

Despite significant interpatient variability, generalizations can be made about the clinical course of illness ( Table 2 ).[5,24] Pertussis infection develops in four sequential stages, beginning with an incubation period during which infected individuals are asymptomatic followed by three stages of symptomatic illness. The incubation period of pertussis infection commonly lasts for 7 to 10 days, but can be as short as 4 days or as long as 21 days. The first stage in which symptoms can be observed is the catarrhal stage. This stage, which typically lasts 1 to 2 weeks, is characterized by the insidious onset of coryza, sneezing, low-grade fever, and a mild, occasional, nonspecific cough that gradually becomes more severe. In young infants, this stage is often characterized by excessive sneezing or “throat clearing.”

During the next stage, the paroxysmal stage, many pertussis patients have bursts, or paroxysms, of numerous, rapid coughs, apparently due to impaired mucociliary clearance. At the end of the paroxysm, a long inspiratory effort is oftentimes associated with a high-pitched whoop. Post-tussive vomiting and cyanosis can also occur. The paroxysmal attacks increase in frequency during the first 1 to 2 weeks, remain at the same level for 2 to 3 weeks, and then gradually decrease.

During the convalescent stage, which lasts for weeks to months, recovery is gradual, with cough becoming less paroxysmal and then disappearing.

The symptomatology of infants during the paroxysmal stage of infection is different from that in adolescents and adults. Although very young infants do experience paroxysms of coughing, they often do not “whoop.” Although the absent whoop in adolescents and adults is usually associated with milder disease, the whoop may be absent in infants because they lack sufficient musculature in the chest wall to take the deep inhalation that creates the whooping sound. The whoop may appear later in the disease as infants gain in size and strength. Infants may also exhibit clinical symptoms such as gagging, gasping, or eye bulging. Occasionally, they may also present with bradycardia or cyanosis. Pertussis is often ignored in the differential diagnosis of cough illness in young infants due to the absence of a “whoop” and the frequency of concomitant respiratory infections.

Life-threatening complications are most common in infants <3 months of age,[19,21] but infection can also be severe in some adult cases. Secondary bacterial pneumonia is diagnosed in up to one quarter of young infants with pertussis[21,25] and is the most common complication and the cause of most pertussis-related deaths across age groups. Data from 1997 to 2000 indicate that pneumonia occurred in up to 5.2% of all reported pertussis cases, and 11.8% of infants <6 months of age.[7] Other complications include seizures (0.8% of all cases, 1.4% of infants <6 months of age) and encephalopathy (0.1% of all cases, 0.2% of infants <6 months of age).

Death due to pertussis is rare (0.2%). The vast majority (90%) occurs in children younger than 6 months of age with no predisposing conditions.[2] Risk factors for death among infants include premature birth, Hispanic ethnicity, and having a young mother.[2,26] Pertussis has also been linked to sudden infant death (3% to 5%).[27,28] Other less severe complications in infants include otitis media, anorexia, and dehydration. Pressure effects of severe paroxysms may lead to pneumothorax, epistaxis, subdural hematomas, hernias, and rectal prolapse. Additional complications identified in adolescents and adults include urinary incontinence, rib fracture, unilateral hearing loss, herniated disk, and precipitation of angina pectoris.[5,24]

Laboratory confirmation of pertussis infection is not as straightforward as that of many other infectious diseases. Most local laboratories are not equipped to make the diagnosis of B. pertussis infection. The preferred approach is polymerase chain reaction (PCR) testing and a culture of the organism from a posterior nasopharyngeal specimen obtained using two separate Dacron swabs.[29] For proper collection, the swab must touch the epithelial cells of the posterior nasopharyngeal wall. Culture is the only method from which antibiotic susceptibilities can be measured and molecular typing determined. Isolation of the organism is compromised by recent antibiotic therapy effective against pertussis (ie, macrolide/azalide or trimethoprim-sulfamethoxazole), by delay in specimen collection beyond the first 2 weeks of illness, and in vaccinated persons.

Serologic testing for B. pertussis is limited by a lack of standardization and should not be obtained for clinical decision making.[30] However, because of its convenience, serology continues to be the most common method used to diagnosis pertussis, especially in the later stages of the infection, making it an important tool in our understanding of disease frequency.[31] Various enzyme-linked immunosorbent assay (ELISA) techniques are available in commercial laboratories, although there is little evidence of sensitivity or specificity relative to clinical infection.[32] None of the commercially available serologic tests for pertussis is FDA-licensed for the routine diagnosis of infection.[14] Direct fluorescent antibody (DFA) is no longer considered useful for diagnosis of pertussis due to low sensitivity and variable specificity.

Pertussis Vaccination of Children

DTaP vaccine, which contains purified, inactivated components of B. pertussis cells (along with tetanus and diphtheria toxoids), has been available in the United States for more than a decade. Since 1997, the CDC recommends DTaP for all doses of the vaccination series for infants and children <7 years of age. The primary immunization series consists of three doses given at 4- to 8-week intervals, beginning at 6 weeks to 2 months of age. A fourth dose is given 6 to 12 months after the third dose. Children who have received all four primary doses before the fourth birthday should receive a fifth (booster) dose before entering school. A fifth dose is not necessary if the fourth dose was administered on or after the fourth birthday.

Point estimates of vaccine efficacy across trials of infants ranged from 80% to 85%.[24] In comparative studies, the acellular pertussis vaccine was significantly more effective than the whole-cell DTP, which is no longer available in the United States. Local and systemic adverse reactions occurred less frequently among infants vaccinated with acellular pertussis vaccine than among those vaccinated with whole-cell pertussis.[34]

Pertussis Vaccination of Adolescents and Adults

The availability of a less reactogenic acellular pertussis vaccine combined with evidence of substantial pertussis infection among adolescents and adults led to reconsideration for the need for acellular pertussis boosters among older subgroups.

Specific formulations of Tdap for adolescents 10 to 18 years, Boostrix® (GlaxoSmithKline), and for adolescents and adults 11 to 64 years, Adacel® (sanofi pasteur), were recently licensed for use in the United States. They contain tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis. In a randomized, controlled, multicenter clinical trial, 10- to 18-year-olds were vaccinated with one dose of Boostrix or a US-licensed Td vaccine.[35] Each subject had completed his or her routine childhood vaccinations against diphtheria, tetanus, and pertussis according to the CDC recommended schedule. Boostrix was comparable to the Td vaccine based on immunogenicity. In both treatment groups, >99.9% of subjects had anti-diphtheria and anti-tetanus concentrations greater than 0.1 IU/mL, indicating seroprotection against these two diseases. In the Boostrix treatment group, anti-pertussis antibodies levels following primary immunization exceeded (by 1.9 to 7.4 times) those observed in infants, in whom efficacy against pertussis disease was previously demonstrated. The overall safety profile was comparable between the Boostrix and Td vaccine groups.

Adacel was evaluated in four principal clinical trials in which 7206 individuals (4185 adolescents and 3021 adults) who had not received tetanus or diphtheria toxoid-containing vaccines within 5 years were enrolled. The trials consisted of one randomized, controlled trial that compared Adacel vaccine to a licensed Td vaccine,[36] one lot consistency trial, and two concomitant administration trials (one with hepatitis B vaccine and one with influenza vaccine). Across trials, a total of 3393 adolescents and 2448 adults received Adacel vaccine and 792 adolescents and 573 adults received Td vaccine. In the largest Adacel trial, the seroprotection rate (of at least 0.1 IU/mL) for tetanus and diphtheria was 99.8% and 100%, respectively.[36] Pertussis antibody geometric mean titers (GMTs) following one dose of Adacel were 2.1- to 5.4-fold higher than those observed among infants following three doses of DTaP. Overall, Adacel vaccine was well tolerated, with local and systemic adverse reactions occurring at similar rates in the Adacel and Td vaccine groups. The ACIP recently revised its recommendations for pertussis vaccination. The immunization schedule now includes a Tdap booster dose for all adolescents at 11 to 12 years of age ( Table 3 ).[37,38] The ACIP also calls for catch-up vaccination of those aged 13 to 18 years who did not receive the Td booster. Finally, because of the importance of controlling pertussis, those in this age range who received the Td booster are encouraged to get the new Tdap vaccine after a suggested 5-year interval. This interval may be shortened to as little as 2 years in the presence of increased risk (eg, during outbreaks or periods of increased pertussis activity in the community).[7]

The ACIP also recommends a single dose of Tdap booster to replace the next scheduled dose of tetanus diphtheria vaccine among persons 19 to 64 years of age. In addition, adults who have or who anticipate having close contact with a vulnerable infant (ie, an infant who has not received two to three doses of DTaP) should receive a single dose of Tdap booster.[39]

In February 2006, the ACIP recommended a single dose of Tdap booster as soon as feasible for health care workers in hospital or ambulatory care settings who have direct patient contact. The Committee stated that priority should be given to vaccination of health care workers with direct contact with infants <12 months of age. Other health care workers should receive a single dose of Tdap booster according to the routine recommendation and interval guidance for use of Tdap among adults.[39]

Widespread administration of Tdap vaccination should have a substantial impact on pertussis. By way of example, adolescent pertussis immunization programs were recently implemented countrywide in Canada, but started earlier in the Northwest Territories and Newfoundland. Following introduction of an adolescent booster dose, pertussis incidence in the Northwest Territories decreased from 7.9 per 100,000 in the late 1990s to 0.2 per 100,000 in 2004.[40] In Newfoundland, no person vaccinated with the Tdap booster has been diagnosed with pertussis to date.[41]

Pertussis is an often serious, potentially deadly community-acquired illness in persons of all ages. Infected adolescents and adults may suffer substantial morbidity and also are a reservoir for disease transmission to infants. Newly available Tdap vaccines are safe and effective in preventing infection. The addition of a pertussis booster to the previously available tetanus and diphtheria booster will not only directly benefit vaccine recipients but may allow for greater control of the pertussis reservoir in adolescents and adults, potentially leading to decreased incidence in infants who are at highest risk for severe complications including death. If widely administered, Tdap vaccination should have a substantial impact on pertussis.

Epidemiology and Transmission of Disease

J Am Board Fam Med.  2006;19(6):603-611.  ©2006 American Board of Family Medicine.