A description of different types of vaccines to prevent poliomyelitis and the differences between them.

1. Venkatesh Karthikeyan,
II year MBBS,
VMCH&RI.
Email : 4852012@gmail.com

2. Viruses
 Don’t have cellular organization
 Contain either DNA or RNA (never both)
 Obligate intracellular parasites
 Lack enzymes necessary for protein and nucleic acid
synthesis
 Multiply by a complex process
 Unaffected by antibacterial antibiotics

3. Virus
 DNA virus
 RNA virus

5. Picornaviruses
 Small RNA virus
 Non-enveloped
 27-30 nm in size
 Resistant to ether and other lipid solvents

6. Picornavirus : Classification
Rhinovirus
Parechovirus
Hepatovirus
Enterovirus
• Poliovirus
• Coxsackie virus
• Echovirus

7. Poliomyelitis
 Poliomyelitis is a highly infectious viral disease
 Transmitted by person-to-person spread mainly
through the faecal-oral route or, less frequently, by a
common vehicle (e.g. contaminated water or food)
 Multiplies in the intestine, from where it can invade
the nervous system and can cause paralysis.
Reference : www.who.int

8. Poliomyelitis
 Acute cases shows neurono-phagia of anterior horn
motor neurons of spinal cord.
 May extend to posterior horn, showing cavitation
 Polio causes :
 Flaccid paralysis
 Muscle wasting
 Hypo reflexia
Ref : Robbins & Cotran Pathologic Basis of Disease (South Asia Edition)

9. Polio can cause irreversible paralysis in a matter of hours

10.  There is no cure for polio
 Only symptomatic treatment can be given
 Can be prevented through immunization

11. Polio Vaccines
 Injectable Polio vaccine (IPV)
 Inactivated Polio vaccine
 Salk’s Killed vaccine
 Oral Polio Vaccine (OPV)
 Sabin’s live attenuated vaccine

12. Polio Vaccines
 Inactivated polio vaccine (IPV) – protects against
poliovirus types 1, 2, and 3
 Trivalent oral polio vaccine (tOPV) – protects against
poliovirus types 1, 2, and 3
 Bivalent oral polio vaccine (bOPV) – protects against
poliovirus types 1, and 3

13.  Monovalent oral polio vaccines (mOPV1) – protect
against poliovirus type 1
 Monovalent oral polio vaccines (mOPV3) – protect
against poliovirus type 3

14. Salk’s killed vaccine
 Developed by Salk in 1953
 Formalin – inactivated preparation of three types of
poliovirus
 Grown in monkey kidney tissue culture

15. Salk’s killed vaccine - Continuation
 Primary vaccination
 Three doses given 4-6 weeks apart
 Booster dose
 Six months later
 First dose given to babies after age of six months
 So that immune response is not impaired by residual
maternal antibodies

16. Salk’s killed vaccine - Continuation
 Enhanced potency IPV produced in human diploid
cells induces better seroconversion
 Two subcutaneous doses 4-8 weeks apart
 Third dose may be given 6-12 months later

17. Sabin’s live attenuated vaccine
 Prepared by growing attenuated strains in monkey
kidney cells
 Single dose given orally is sufficient
 In practice, three doses are given at 4-8 weeks intervals
 To ensure all three types of vaccine virus multiply in
intestine – overcoming interference among themselves
and other enteric viruses

18. Sabin’s live attenuated vaccine - Continuation
 OPV used in India contains
 Type 1 virus 10 lakh
 Type 2 virus 2 lakh
 Type 3 virus 3 lakh
 Thermostabilised with MgCl2
 pH maintained below 7 by keeping vaccines in airtight
containers

19. Sabin’s live attenuated vaccine - Continuation
 Shelf life of vaccine at 4-8 degree Celsius is four
months
 Shelf life of vaccine at -20 degree Celsius is 2 years

21. Difference between IPV and OPV
Number IPV (Salk type) OPV (Sabin type)
1. Cost of manufacture High Low
2. Storage • Stringent conditions
for storage and
transport not required
• Longer shelf life
Needs to be stored and
transported at sub zero
temperatures, unless
stabilized
3. Administration to
immunocompromised
host
Is allowed Not recommended

22. Difference between IPV and OPV(Continuation)
Number IPV OPV
4.Route of administration Subcutaneous or
intramuscular
Oral
5. Type of virus Killed formolised Live attenuated
6. Immunity • Systemic immunity is
good
• Mucosal immunity is
slight to moderate
• Systemic immunity is
good
• Mucosal immunity is
excellent

23. Difference between IPV and OPV(Continuation)
Number IPV OPV
7. Mutations leading to
reversal of virulence
Not Known Possible
8. Interference of vaccine
efficiency by enteric virus
No interference Interference is possible
9. Vaccine associated
disease complication?
No Possible

24. Take Home Message
Salk’s Killed Vaccine:
 Primary vaccination
 Three doses given 4-6 weeks apart
 Booster dose
 Six months later
Sabin’s live attenuated Vaccine :
 Three doses are given at 4-8 weeks intervals

25. Thank you :)