POLIO
VIRUS VACCINE
(LIVE, ORAL, TRIVALENT)
By
C.V. MALLIKARJUNA MURTHY, M.Sc.
Senior Drugs Inspector, Tamilnadu
ORAL POLIO vaccine has become very popular
with the public. Now a days it is being given
to almost all children as a matter of routine.
There is considerable demand for the vaccine
even in villages. The Chemists and Druggists,
because of the demand have started selling and
dispensing this vaccine. There are various precautions
to be taken during storage, transportation and
administration of this vaccine. If they are
not taken the vaccine cannot be effective. But
the parents of the child will be thinking that
the child is really protected when it is not.
The agony of the parents and the misery of the
child can very well be imagined when a child
who received that ineffective vaccine gets polio
later on. The damage cannot be undone. The damage
lasts for the entire life of the child.
It is therefore necessary to know what this
polio is, what this oral polio vaccine does,
and the manner in which it needs to be stored
and dispensed.
What is Polio
?
Poliomyelitis or polio as is commonly known
is an acute infectious disease primarily of
children which affects the central nervous system.
The disease is caused by an enterovirus known
as the polio virus with three distinct antigenic
serotypes, type 1,2, and 3. The virus is rapidly
inactivated by heat, dessication formalin, chlorine
and Ultra violet irradiation.
The incubation period, on an average is 17
days and the infection spreads through faecal
to oral route. It is primarily an infection
of the alimentary tract with the virus multiplying
in the regional lymph nodes. Clinical evidence
of the Infection starts only when the virus,
after multiplying in the lymph nodes passes
into the blood system and localizes in the Central
nervous system. Only a small percentage of the
infected persons suffer from a clinical disease
and in only a minority of these there is paralysis
or meningo encephalitis.
There is no specific treatment for the paralysis
produced by the poliovirus. In addition to the
general supportive measures that are recommended
in any acute infectious disease physiotherapy
must be initiated immediately. Physiotherapy
is of vital importance in acute and convalescent
phases and must not be ignored under any circumstances.
Oral polio vaccine is most valuable as prophylactic
agent. It has no curative value.
What is a Vaccine
?
Vaccines are either dead or living attenuated
organisms administered to an individual either
for prophylaxis or sometimes to ameliorate the
disease caused by the organisms with the hope
of providing development of antibodies in vivo.
Thus vaccines are generally administered for
prophylactic purposes i.e. to prevent the disease.
Oral Polio Vaccine and B.C.G. Vaccines are examples
of vaccines containing live attenuated organisms.
While the Oral Polio Vaccine is called the Sabin
Vaccine, the Killed Polio Vaccine(K.P.V.) is
called the Salk vaccine. The former is given
orally while the latter is given parent rally.
Sabin and Salk are the names of the discoverers
of the vaccine.
What is Oral
Polio Vaccine ?
Oral Polio vaccine is comprised of the three
serotypes of polio viruses duly attenuated.
The viruses are usually propagated in Kidney,
tissue culture. The potency is expressed in
terms of the amount of virus contained in the
recommended does as tissue culture ineffective
doses, (TCID 50). The approximate concentration
of polio virus in each strain in a 0.5 c.c.
dose or a 2 drops dose is as follows :
Type 1 800,000
Type 2 100,000
Type 3 500,000 doses
What is the Colour
of the Vaccine ?
Oral polio vaccine normally contains phenol
red as a PH indicator. The colour of the vaccine
is pink although some containers of the vaccine
stores in dry ice may exhibit a yellow colouration,
due to the very low temperature or possible
absorption of carbon –dioxide. The colour
of the vaccine prior to use (red-pink-yellow)
has no effect on the virus or the efficacy of
the vaccine. If however, a multiple dose container
of vaccine turns from red to pink to yellow
after it has been thawed and entered it should
not be used since this may be an indication
of Bacterial contamination.
Why is Oral Polio
Vaccine given ?
The purpose of administering any attenuated
live virus vaccines is to stimulate the body
mechanism to produce an active immunity by stimulating
the natural infection without producing untoward
symptoms of the disease. The accomplish this
with live polio virus vaccine it is necessary
for the virus to multiply in the intestinal
tract. A primary series of this vaccine is designed
to produce an antibody response to polio virus
types 1,2 and 3 . This response is comparable
to the immunity induced by the natural disease.
The antibodies thus formed help to protect the
individual against clinical poliomyelitis infection
by all three types of polio virus.
How should the
Oral Polio Vaccine be stored ?
The shelf life of the vaccine depends on the
manner of storage adopted. The shelf life is
2 years when stored at 24° C, 6 months when
stored at +4° C and 21 days when stored
at +22° C as per a manufacturer ‘s
claim. Bulk storage of vials (unopened) should
be in a deep freeze at sub zero temperatures.
During administration the vials of the vaccine
must be stored in ice.
The vaccine should not be frozen and thawed
repeatedly since repeated freezing and thawing
has a deleterious effect on the potency of the
oral polio vaccine. The efficacy of the vaccine
depends entirely on the administration of live
viruses to the individual. If somehow or other
any proportion of the living viruses of any
of the serotypes is inactivated, the vaccine
of any of the serotypes is inactivated , the
vaccine ceases to be an effective immunizing
agent. With the use of such vaccines which contain
significant proportion of inactivated virus,
one is actually a false sense of security.
An un-opened container of vaccine that has
been frozen and then is thawed may be carried
through a maximum of 10 freeze thaw cycles provided
the temperature does not exceed 8°C during
the periods of thaw and provided the total cumulative
duration of thaw does not exceed 24 hours. If
the 24 hours period is exceeded the vaccine
then must be used within 30 days during which
time it must be stored at a temperature no higher
than 8°C.
What are the
precautions to be taken during administration
?
a) Administer the appropriate quantity of the
vaccine by withdrawal from the vial through
a sterilized syringe.
b) Sterilize the individual spoon in boiling
water or steam and cool it completely before
transferring individual dose to it from the
vaccine vial.
c) Do not dilute the vaccine in water, milk
or syrup before its administration to the child.
d) Do not sterilize the spoon to be used for
vaccination with any disinfectant like Dettol,
Lysol, or any other antiseptic.
e) Do not give oral polio vaccine in hot humid
and crowded room. The vaccine should be given
preferably in an air-conditioned room.
f) Do not administer any batch of oral polio
vaccine unless you are sure that the vaccine
was kept frozen during its transport to your
organization.
Is there any
special advice for the parents of the child
receiving polio vaccine ?
a) Oral polio vaccine is to be given to all
children more than 3-6 months of age.
b) Three dosed of the vaccine at monthly intervals
are to be given to protect the child adequately.
c) The vaccine should not be given to any child
suffering from dysentery, diarrhea, vomiting
and fever. Similarly it should not be given
if the child is on cortico-steroids.
d) Breast feeding must be stopped for a period
of at least six hours before as well as after
the administration of the vaccine. During this
period the child must be fed artificially. The
child should not be starved.
e) Hot drinks like tea,coffee or milk must
not be given for a period of half an hour after
the administration of the vaccine.
Will Oral Polio Vaccine prevent, modify existing
or incubating polio myelitis
No.
Can Oral Polio Vaccine be given to children
below six weeks old
Administration to the new borne under six weeks
is not generally performed because of varying
persistence of material antibodies.
How safe is administration
of Oral Polio Vaccine ?
Expert opinion is in agreement that administration
of live oral polio vaccine is generally an effective
and safe method of protecting population against
the natural disease.Paralytic diseases following
the ingestion of live polio virus vaccines has
been reported in individuals receiving the vaccine
and in some instances in persons who were in
close contact with subjects who had been given
live oral polio vaccine. The rare occurrences
of “Vaccine related cases “ were
considered compatible with vaccine induced disease.
It has been estimated that the risk of vaccine
induced paralytic polio myelitis is about one
chance per million doses. The risk must be considered
by the physician and such information should
be conveyed to the parents at the time of vaccination.
How often it
is necessary to give Oral Polio Vaccine ?
Primary series is given as stated when the
child is between 3 to 6 months of age. A total
of three doses are given at monthly intervals.
Thereafter on entering elementary school all
children who have completed primary series should
be given a single follow up dose. Booster dosed
thereafter are considered not necessary.
How long can
the un-opened Oral Polio Vaccine in the liquid
state be effective ?
Un-opened vials of the vaccine in liquid state
may be used for upto 30 days provided they have
been stored at 2° to 8°C during that
period.
How long can
the opened vials be effective ?
Once opened the vaccine must be refrigerated
and used within 7 days.
Thus it may seen that great care is necessary
when handling oral p
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