Posted by: Chris Maloney | August 25, 2011

Would Vaccinating Everyone for Whooping Cough Prevent Infant Deaths Like the One in Snohomish?

This image depicts a young boy who presented t...

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The report of an infant death of whooping cough will have far-reaching implications as public health officials push to have everyone vaccinated or revaccinated for pertussis.

One health official compared the lack of universal vaccination to “societal malpractice,” so I hope we’ve got our “societal malpractice insurance” paid in full.

The simplistic view that universal vaccination would prevent this tragedy is alluring.  It gives an easy target to point to and a ready solution.  As the health official says, all we need to do is vaccinate 95% of the population.  Let’s get the needles ready!

But would it have really saved the infant?  Studies on well-vaccinated children in South Africa found that with even a 95% vaccination rate “was not able to prevent a moderate scale outbreak, even in the presence of high vaccination levels.” (abstract below).  A more recent study published this July from Spain found that a high rate of vaccination did not prevent correctly vaccinated children from contracting whooping cough during an outbreak.

What is clear from the evidence is that an infant like the one in Snohomish might still contract and die from whooping cough despite universal vaccination.  It does not mean we shouldn’t consider vaccinating the entire population for whooping cough.  Doing so would very likely drop the number of cases and might well prevent a few deaths.  But it would not necessarily have prevented this infant’s death.

Enferm Infecc Microbiol Clin. 2011 Jul 18. [Epub ahead of
print]

[Outbreak of whooping cough with a high attack rate in
well-vaccinated children and adolescents.]

[Article in Spanish]

Torres J, Godoy P, Artigues A, Codina G, Bach P, Mòdol I,
Duró MA, Trilla C.

Source

Unitat d’Epidemiologia, Departament de Salut, Lleida,
España; Universitat de Lleida, Lleida, España.

Abstract

INTRODUCTION:

Whooping cough is a re-emerging disease. We describe the
investigation of an outbreak of whooping cough and the measures of control
adopted.

METHODS:

The event was reconstructed through a longitudinal study of
incidence. In addition to the notified cases, an active search from the list of
those who attended summer camps was made through telephone calls. An
epidemiological survey was applied to all cases; vaccination history was
confirmed with computerised clinical history and the obtaining of samples for
analytical confirmation was proposed. The description of the outbreak was made
through the epidemic curve, the attack rates, the relative risk and the linear
trend by ages and the vaccination coverage.

RESULTS:

Of the 30 cases that appeared, 22 (73.3%) were among the
members of the summer camps. In these, the attack rate was 21.8%, 26.7% among
the children and adolescents increasing linearly with the age. The large
majority (86.4%) of this last group were correctly vaccinated, including the
fifth dose at the age of 4-6 years. Through the meticulous study of the first
cases and the telephone calls to those who attended the summer camp, 90% of the
cases of the outbreak were detected.

CONCLUSIONS:

The active search of cases allowed an outbreak of whooping
cough with a high attack rate to be studied in children and adolescents with a
high vaccination coverage, and the application of control measures that
contributed to stop the outbreak.

Copyright © 2010 Elsevier España, S.L. All rights reserved.

PMID: 21775027

J Trop Pediatr. 1991 Mar;37(2):71-6.

An outbreak of whooping cough in a highly vaccinated urban
community.

Strebel P, Hussey G, Metcalf C, Smith D, Hanslo D, Simpson
J.

Source

Centre for Epidemiological Research, South African Medical
Research Council, Tygerberg.

Abstract

In 1950 a whole-cell pertussis vaccine was introduced in
Cape Town and was followed by a marked decline in reported whooping cough
mortality and morbidity. This resulted in reduced awareness of whooping cough
as a clinical problem and, in recent years, no routine diagnostic tests for
Bordetella pertussis have been performed. An outbreak of whooping cough
occurred in Cape Town between 1 June 1988, and 31 May 1989, with 292 children
admitted to hospital for whooping cough during this period (hospital admission
rate in children under 5 years of age = 187 per 100,000). In an investigation
of 239 children attending four pre-primary schools in the city, the whooping
cough attack rate was 33 per cent, while pertussis vaccine coverage was 95 per
cent. In the latter part of the outbreak nasopharyngeal swabs and serology were
performed in patients presenting to a children’s hospital with suspected
whooping cough. Bordetella pertussis was isolated from 3 out of 34 (9 per cent)
children tested and the first isolate was serotyped as type 1,2,4. Available
clinical and laboratory evidence indicated that the organism responsible for
the outbreak was Bordetella pertussis. Coverage studies for pertussis vaccine
in Cape Town indicated that between 81 and 93 per cent of children were fully
immunized by 13 months of age. These findings suggest that, since its
introduction, the whole-cell pertussis vaccine produced in South Africa has
been highly effective in controlling whooping cough. However, it was not able
to prevent a moderate scale outbreak, even in the presence of high vaccination
levels.

PMID: 2027168

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