This document discusses poliovirus and the polio vaccines. It provides background on the history and epidemiology of polio, including the three virus serotypes. It describes the structure and pathogenesis of poliovirus. It then summarizes the inactivated polio vaccine (IPV) and oral polio vaccine (OPV), including how each provides immunity. It outlines the childhood vaccination schedules and combination vaccines that include polio vaccines. It concludes by discussing the standardization of poliovirus vaccines.

1. Romil Mistry
7th Sem M.Sc. B.T
Bhagwan Mahavir College Of Science & Technology , Surat

2. First outbreak described in the U.S. in 1843
More than 21,000 paralytic cases reported in the U.S. in 1952
• Three serotypes of wild polio virus: WPV1
,WPV2 ,WPV3
• Minimal heterotypic immunity between
serotypes
• Rapidly inactivated by heat, chlorine,
formaldehyde, and ultraviolet light
• Genus : Enterovirus
• Species : poliovirus
• Structure : ssRNA enclosed in a capsid
• Size : 30nm in diameter with icosahedral
symmetry

4. Poliomyelitis Pathogenesis
• Entry into mouth
• Replication in pharynx and GI
tract
• Hematologic spread to
lymphatics and central
nervous system
• Viral spread along nerve
fibers
• Destruction of motor neurons

5. Reservoir Human
Transmission Fecal-oral Oral-oral possible
Communicability Most infectious: 7-10 days before
onset Virus present in stool 3-6 weeks
Poliovirus Epidemiology

7. In INDIA……..

8. Poliovirus Vaccines
 1955 - Inactivated
vaccine
 1963 - Trivalent OPV
 1987 – Enhanced-potency
(IPV)

9. Inactivated polio vaccine (IPV)
• IPV is produced from wild-type poliovirus strains of each serotype that
have been inactivated (killed) with formalin.
• As an injectable vaccine, it can be administered alone or in combination
with other vaccines (e.g., diphtheria, tetanus, pertussis, hepatitis B, and
haemophilus influenza).
• Generally three spaced doses are administered to generate adequate
levels of seroconversion, and most countries, a booster dose is added
during late childhood. IPV has been used successfully in the polio
eradication programs in a few countries, notably in Scandinavia and the
Netherlands, but until recently most countries have used the oral polio
vaccine.
• IPV provides serum immunity to all three types of poliovirus, resulting
in protection against paralytic poliomyelitis.

10. Standardization
• The requirements for poliomyelitis vaccine (inactivated) were first formulated in
1959 and revised in 1965.
• Following several advances in technology in vaccine production, the requirements
were further updated in 1981 and amended in 1985.
• At that time, the introduction of continuous cells for manufacture of poliomyelitis
vaccine (inactivated) (IPV) was a novel development and when the control of
products manufactured in continuous cells had been standardized, the requirements
again updated in 2000.
• An addendum was added in 2003 which specifies steps to be taken to minimize the
risk of reintroducing wild poliovirus from a vaccine manufacturing facility into the
community after global certification of polio eradication.

12. Childhood Polio Vaccination Schedule
IPV Dose
• 1
• 2
• 3
• 4
Routinely
Recommended at
• 2 months of age
• 4 months of age
• 6- 18 months of age
• 4-6 years of age
Minimum
Interval
• 4 weeks
• 4 weeks
• 6 months

13. Poliovirus-containing Vaccine
Products
Single component vaccine - IPV (IPOL)
FOUR polio-containing combination vaccine products:
• DTaP-IPV/Hib (Pentacel)
• DTaP-HepB-IPV (Pediarix)
• DTaP-IPV (Kinrix)
• DTaP-IPV (Quadracel)

14. Oral polio vaccine (OPV)
• OPV consists of a mixture of live attenuated poliovirus strains of each of the three
serotypes, selected by their ability to mimic the immune response following infection
with wild polioviruses, but with a significantly reduced incidence of spreading to the
central nervous system.
• Three or more spaced doses of OPV are required to generate adequate levels of
seroconversion.
• OPV produces antibodies in the blood ('humoral' or serum immunity) to all three
types of poliovirus, and in the event of infection, this protects the individual against
polio paralysis by preventing the spread of poliovirus to the nervous system.
• OPV strains also produce a local immune response in the lining ('mucous membrane')
of the intestines - the primary site for poliovirus multiplication.
• The antibodies produced there inhibit the multiplication of subsequent infections of
'wild' (naturally occurring) virus. This intestinal immune response to OPV is probably
a reason why mass campaigns with OPV have been shown to stop person-to-person
transmission of wild poliovirus.

16. • Requirements for poliomyelitis vaccine (oral) were first formulated in 1962 and
revised in 1966 and 1972 when an appendix detailing the production of OPV in
human diploid cells was added.
• The Requirements were further updated 1982 following an accumulation of data
particularly on the performance and evaluation of the monkey neurovirulence test
and tests on the karyology of human diploid cells.
• The recommendations were updated in 1989 to take account of the general
requirements for the characterization of continuous cell lines for the preparation of
biologicals which were adopted in 1985 and after a WHO Study Group concluded
that, in principle, such cell lines are acceptable as substrates for the production of
biologicals.
• The requirements were last revised in full in 1999 when new quality control tests
were introduced for the vaccine including the test in TgPVR21 mice as an alternative
to the monkey neurovirulence test for poliovirus type 3.
• An addendum was approved in 2000 to extend the use of this test to all three
poliovirus serotypes.
Standardization

17. Thank You