Bordetella pertussis and Whooping Cough (page 3)
(This chapter has 3 pages)
© Kenneth Todar, PhD
The Whooping Cough Vaccine
The development of the whooping cough vaccine in the 1950s has made
cough an uncommon disease in developed countries. In countries where
vaccine is not used whooping cough is an important cause of mortality
with an estimated 51,000,000 cases and 600,000 deaths annually.
Historically, the whooping cough vaccine has been administered as a
merthiolate-killed bacterial cell suspension which is part of the DTP
(The P in DTP stands for Pertussis cells). Unfortunately, about 20% of
the children that receive the whole cell vaccine experience
side effects. About 0.1% of infants experience convulsions soon after
the vaccine and in a very small number of cases (1 in 150,000?) severe
or irreversible brain damage may occur. In the absence of the disease
an immune population, parents have begun to wonder if the risk of
children outweighs the risk of the disease, and the value of the whole
cell vaccine has been questioned.
Several new acellular vaccines have been developed from
components of B. pertussis. Demonstration of the protective
of anti-PTx and anti-FHA antibodies in the mouse model, focused vaccine
production on combinations of inactivated pertussis toxin (toxoid) and
filamentous hemagglutinin. Multicomponent acellular vaccines containing
combinations of pertussis toxoid, filamentous hemagglutinin, pertactin,
and the two types of fimbriae, are now being used in several countries
including the U.S. The new vaccine, known as acellular pertussis
has fewer side effects than the whole cell vaccine and is currently
for use under the conditions described below.
For decades, the pertussis vaccine has been given in combination
vaccines against diphtheria and tetanus. The combination is known as
vaccine. Recently, infants have been able to receive a vaccine that
the DTP vaccine with the vaccine against Haemophilus influenzae
type b meningitis (Hib). This vaccine is called DTPH. The
vaccine using acellular pertussis is known as DTaP. The
vaccination is given in five doses: at 2, 4, 6, 12-18 months and 4-6
of age. Previously, DTaP had been recommended only for the fourth and
doses. Following FDA licensure of DTaP for infants, the Advisory
on Immunization Practices of the United States Public Health Service
recommends that DTaP be used for the first four doses and that DTaP
be used for the fourth and fifth doses for children who received DTP in
their first three doses. The Committee is awaiting study results before
making a recommendation for the fifth dose for children who now will
DTaP in their first four doses. The recommendation still permits the
of DTP and DTPH--the combination that includes the vaccine against Haemophilus
influenzae type b meningitis.
Whooping Cough In Wisconsin 2004
There were more than 4,800 cases of whooping cough were reported in
Wisconsin in 2004, an increase of more than 690 percent over the
year, when there were 716. In the mid-1980s, when whooping cough
were considered particularly bad, there were 400 to 500 reported cases
Dane County reported over 150 cases. The Public Health Department of
the City of Madison saw over 100 cases in 2004, even though the disease
is undoubtedly under-reported. The University Health Services saw a
in incidence on the UW campus. Last semester UHS confirmed several
cases each week, with several additional unconfirmed occurrences.
Since the development of the pertussis vaccine, the incidence of
cough in the U.S. steadily declined until the past two decades when it
began to rise. According to the Center for Disease Control, Wisconsin
ranks second in the nation for disease incidence rate at 27.7 cases per
It is difficult to draw conclusions by comparing the 2004 outbreak
those in past years. The increase in whooping cough numbers can
be explained by new testing procedures that became available last year.
The new test is quicker and more sensitive than previous tests, and
are putting more emphasis on diagnosing the illness.
Also, whooping cough infections tend to run on a 2-5 year cycle, and
2004 could be a high point in the cycle.
Like flu viruses, the bacterium is highly contagious and tends to
quickly from person to person through coughing and sneezing. If
numbers of individuals have the illness, then the risk of infection
in the general population.
Many young children are vaccinated against whooping cough with the
vaccine. However, the vaccine is only approved for children under seven
years of age. Antibody-mediated immunity wanes in approximately ten
leaving older individuals more susceptible to the disease. Adults get
often to a lesser degree, but they are still able to spread the disease
to unimmunized children.
For more information on whooping cough, see the CDC listings under
whooping cough Pertussis
- Technical Information
END OF CHAPTER
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