Poliomyelitis Paul R' Earl Facultad de Ciencias Biolgicas Universidad Autnoma de Nuevo Len San Nicol

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PoliomyelitisPaul R. EarlFacultad de Ciencias
BiológicasUniversidad Autónoma de Nuevo LeónSan
Nicolás, NL, Mexico 66451pearl_at_dsi.uanl.mx
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Poliomyelitis is an acute infectious disease of
humans, particularly children, caused by any of
three serotypes of human enteric poliovirus.
Usually the infection is limited to the
gastrointestinal tract and nasopharynx and is
often asymptomatic. The central nervous system
(CNS), primarily the spinal cord, may be
affected, leading to rapidly progressive
paralysis, coarse fasciculation and hyporeflexia.
Motor neurons are primarily affected.
Encephalitis may also occur. The virus multiplies
in the nervous system and may cause significant
neuronal loss, most notably in the spinal cord.
Acute flaccid paralysis of the legs is common.
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The reality of infantile paralysis in the days
before persistent vaccination solved this
tragedy.
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The wartime President and Eleanor
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History. Michael Underwood
described poliomyelitis as a debility of the
lower extremities in the second edition of his
book Treatise on the Diseases of Children, 1789.
In 1840, Jacob von Heine described anterior acute
poliomyelitis and the differences with other
types of paralysis. Lesions in the spinal medula
were demonstrated in 1870 by Jean-Martin Charcot
Alex Joffroy. The Bavarian neurologist Wilhelm
Heinrich Erb coined the term anterior acuta
poliomielitis for clinical adult cases. In
Greek, polios means grey and myelos medula. Of
course, the ending itis means inflammation of.
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Karl Landsteiner (1868-1943)
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(1906-1993)
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In 1953-55, Jonas Salk at the University of
Pittsburgh, Pittsburgh, Pennsylvania, using
primary monkey kidney cells, produced a
successful formalin-killed trivalent (all 3
serotypes) vaccine that had production and field
trials at the Connaught Laboratories then
affiliated to the University of Toronto now
Aventis Pasteur. Salks inactive vaccine was also
tested in the US.
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Look at the term PRIMARY. That cell line
originated from some animal or human, and in this
case rhesus monkeys that are very expensive and
sometimes protected by religions in Asia. As the
primary line will become senescent and die out,
the practical polio vaccine problem is paying for
enough monkeys. Only sex and cancer cells are
immortal. Secondary lines like HeLa cells (Helen
Lane, donor, cancer of uterus) cannot be used for
vaccine production. Human diploid cells can be
used as they have fairly normal chromosome
behavior (2n 46).
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Oral vaccines.Except for oral live
vaccines by 1955, the stage was set for polio
eradication, although it was never considered at
that time. Generally, live vaccines leave a
higher neutralizing antibody titer than
formalinized or otherwise killed vaccines.
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Three teams engaged in the vaccine race a)
Lederles, b) Wistar and c)
Cincinnati.More fully, these were Lederle
Laboratories, Pearl River, NY under Herald Cox,
Wistar Institue of the University of
Pennsylvania, Philadelphia, PA under Hilary
Kaproski, and Microbiology of the University of
Cincinnati, Cincinnati, OH under Albert Sabin.
The Lederles attenuated strains has been under
development since 1946 by Cox Kaprowski.
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In a half century, 2 emminently successful
vaccines, oral (OPV) vs inactivated (IPV) have
driven wild serotypes to virtual extinction. In
1952, 58,000 cases of polio were registered in
the US. In 1960 with vaccinations started in
1957, cases dropped to 3,000 which is amazing.
Persistant high-coverage vaccines have driven
some of the formerly vicious infections out of
business. In 2001, in the world 537 cases of
polio were recognized in 10 countries Angola,
Nigeria, Niger, Ethiopía, Afganistán, Pakistán,
Egypt, Sudan, Somalia and India. Eradication is
on the horizon.
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Vaccine recommendations. 1/ IPV is routinely
recommended for all children at 2-4 months of age
for the first 2 doses of the poliovirus vaccine
schedule. Immunization with OPV is acceptable
when parents refuse either IPV or the number of
injections needed to administer the other
recommended vaccines for infants.
2/ With either the sequential or IPV-only
regimen, OPV or IPV should be given at 6-18
months and 4-6 years of age for a total of 4
doses of polio vaccine administered before school
entry. Note that a child can have an underlying,
unrecognized immunodeficiency.
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Vaccine recommendations. (cont) 3/ Only IPV
is recommended for the following a)
immunocompromised persons and their household
contacts because OPV is contraindicated in these
individuals and b) infants and children in
households with persons older than 17 years who
are known to be inadequately vaccinated against
polio, because of the increased risk of VAPP in
susceptible adults.
4/ For infants and
children in whom the routine immunization
schedule is not initiated until after 6 months of
age and in whom an accelerated schedule is
necessary to fulfill immunization
recommendations, an OPV-only regimen is
acceptable to minimize the number of injections
at each visit.
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5/ For children who may be traveling to areas
where wild-type polioviruses like Mahoney are
still endemic, selection of IPV or OPV depends on
the interval until departure and the number of
doses of polio vaccine previously received. For
children who already have received 2 doses of
IPV, administration of 2 doses of OPV at an
interval of 1 month will provide optimal
intestinal immunity.
6/ If an outbreak
of wild-type poliovirus infection occurs in the
United States, OPV is the vaccine of choice to
control most effectively the spread of infection.

7/ As with
administration of all vaccines, parents and child
care people should be informed of the benefits
and risks of the different poliovirus vaccines
and regimens, including the risk of VAPP from
OPV. But all polio vaccines are on the way out.
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The Global Polio Eradication Initiative. In
1988, the 41st World Health Assembly of the
delegates from 166 Member States, launched a
global initiative to eradicate polio by the end
of the year 2000. This followed the certification
of the eradication of smallpox in 1980, progress
during the 1980s towards elimination of the
poliovirus in the Americas, and Rotary
Internationals commitment to raise funds to
protect all children from the disease.
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In 1994, the World Health Organization (WHO)
Region of the Americas (36 countries) was
certified polio-free, followed by the WHO Western
Pacific Region (37 countries and areas including
China) in 2000 and the WHO European Region (51
countries) in June 2002. Widely endemic on five
continents in 1988, polio is now found only in
parts of Africa and south Asia.
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Before a WHO region can be certified polio-free,
three conditions must be satisfied a) at least
three years of zero polio cases due to wild
poliovirus b) excellent certification standard
surveillance c) each country must illustrate the
capacity to detect, report and respond to
imported polio cases. Laboratory stocks must be
contained and safe management of the wild virus
in Inactivated Polio Vaccine (IPV) manufacturing
sites must be assured before the world can be
certified polio-free.
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The Global Polio Eradication Technical
Consultative Group (TCG) is overseeing a program
of research and consensus-building which will
lead to the development of posteradication polio
immunization policy options. WHO, Rotary
International, the US Centers for Disease Control
and Prevention (CDC) and the United Nations
Childrens Fund (UNICEF) form a coalition
financing world eradication as shown in the pie
chart.
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The polio eradication coalition includes the
governments of affected countries, private
foundations like the United Nations Foundation
and Bill Melinda Gates Foundation, development
banks, donor governments as Australia, Austria,
Belgium, Canada, Denmark, Finland, Germany,
Ireland, Italy, Japan, Luxembourg, Netherlands,
Norway, United Kingdom and US, the European
Commission, humanitarian and non-governmental
organizations like the International Red Cross
and Red Crescent societies, and corporate
partners of Aventis Pasteur, De Beers and Wyeth.