Poliovirus and Polio Vaccines

Poliovirus

It is an infectious disease caused by poliovirus which affects the spinal cord and brain stem, it leads to paralysis and even leads to death.

• Poliovirus is the causative agent of poliomyelitis.
• Children under 5 years of age are more susceptible to this disease.
• Reservoir Human.
• Spread through feces.
• Contaminated food and water.
• So, it spread in the communities with poor infrastructure.
• Poor sanitation.
• Crowded living conditions.
• Young children are particularly at risk of infection.

History and epidemiology

• Poliovirus was first described by MICHAEL UNDERWOOD in 1789.
• The first outbreak described in the U.S in 1843.
• 21000 paralytic cases were reported in the U.S in 1952.
• Polioviruses are distributed globally before the availability of immunization, almost 100% of the population in developing countries before the age of 5.
• The availability of immunization and the poliovirus eradication campaign has eradicated poliovirus in most regions of the world except in the Indian subcontinent and Africa.
• In 1908 transmission of polio to a monkey by Landsteiner was confirmed. The virus was grown on tissue culture in 1949.
• Three types of poliovirus were isolated and identified in 1951.
• Trials of Salk vaccine: The first large scale trial of Salk was performed in 1954. The use of Sabin in 1958 first general use of Sabin was done.
• As a result of the massive global vaccination campaign over the past 20 years, polio exists only in a few countries in Africa and Asia. In the Philippines, the last case was reported in 1993 and in 2000 the Philippines was certified as a polio-free country.

Image Source: Wikipedia and JAMA Forum

Types of polio vaccine

Inactivated Polio Vaccine

• Synonyms for IPV vaccine
• e-IPV
• ep-IPV
• Salk vaccine
• IPV is a trivalent (strains 1,2,3) vaccine.

Salk Polio Vaccine

– Jonas firstly developed the Salk vaccine

1) Formaldehyde-fixed

2) Non-reversion (this inactivated polio vaccine cannot revert back, np side effect and safe to use).

3) types of poliovirus grown in monkey kidney tissue culture.

Procedure for preparation

• Standard virulent strains used.
• 3 types of polio vaccines grown separately in MKTC.
• Adequate titer filtered to remove debris and clumps.
• Inactivated with formalin at 37 degrees for 12-15 days.
• Stringent tests to ensure complete inactivation
• Issued for use.

History

• In 1954 the whole USA was vaccinated against polio and 80-90% population was protected.
• In 1955 100 cases of poliomyelitis were reported due to the insufficiently inactivated vaccine.

Merits

• IPV produces antibodies in the blood to all three types of poliovirus.
• As IPV is not a live vaccine, it carries no risk of VAPP.
• IPV triggers an excellent protective immune response in most people. • Shipping and transport are easy.

Demerits

• IPV is over 5 times more expensive than OPV
• A booster regime is required.
• Do not stimulate local and mucosal immunity
• Administering the vaccine requires trained workers, as well as sterile injection, equipment, and procedure.

Oral Polio Vaccine

• Trivalent oral polio vaccine.
• A synonym is the Sabin vaccine.
• Developed by Albert Sabin in 1961.
• It is a live attenuated virus vaccine.
• Oral administration of vaccine yields a local gastrointestinal infection.
• A major caution with TOPV is that it is a live vaccine and must never be injected.

Preparation

• Attenuated by a passage in the foreign host (MKC)
• Selection to grow in new in host makes viruses.
• Less sited to the original host.
• Stabilizers such as sucrose or trehalose or arginine hydrochloride may be added to retain the antigenicity.
• Inactivation is carried out by adding formalin at 0.025% concentration.
• Incubation at 37centigrade up to 48 hours and then at 23 centigrade up to 12 days.
• Test for free formaldehyde content after 12 hours consistent inactivation of the virus is monitored and verified.

Advantages

• Oral polio vaccines are easily administered, with no need for highly trained.
• Induce both humoral and systemic immunity.
• Antibodies quickly produce as 1 or 2 doses of oral vaccine can give 90-100% results.

Disadvantages

• Instability at high temperature.
• Very small residual neurovirulence in OPV.
• Frequent vaccine failure even with fully potent.

Storage of polio vaccine (OPV and IPV)

• OPV is a heat sensitive vaccine.
•  Stored at -20 degrees.
• Having shelf life…
• 2 years at -20 degree
• 6 months at 2-8 degree
• 1-3 days at room temp.

References

• https://en.wikipedia.org/wiki/Polio_vaccine.
• https://www.cdc.gov/vaccines/vpd/polio/public/index.html.
• https://www.who.int/biologicals/areas/vaccines/polio/opv/en/.
• http://polioeradication.org/polio-today/polio-prevention/the-vaccines/ipv/.
• https://immunizationforwomen.org/providers/diseases-vaccines/poliomyelitis/vaccine-recommendations-safety.php.
• https://www.britannica.com/science/polio-vaccine.
• https://www.vaccines.gov/diseases/polio.

Sources

• 16% – https://www.slideshare.net/Muhammadiqbal583/polio-vaccine-85407875
• 6% – https://judoctor2011.files.wordpress.com/2014/02/lecture-3.pdf
• 3% – https://www.slideshare.net/leehimangsu13/poliomyelitis-53216812
• 3% – https://quizlet.com/85252674/mc_f2-flash-cards/
• 3% – http://polioeradication.org/polio-today/polio-prevention/the-vaccines/ipv/
• 2% – https://www.medicinenet.com/polio_facts/article.htm
• 2% – http://www.freepatentsonline.com/y2008/0193478.html
• 1% – https://www.vaccines.gov/basics/types
• 1% – https://www.smartparenting.com.ph/health/your-kids-health/polio-outbreak-philippines-a00228-20190922-lfrm
• 1% – https://www.sciencedirect.com/topics/medicine-and-dentistry/poliomyelitis
• 1% – https://medlineplus.gov/polioandpostpoliosyndrome.html
• 1% – http://www.allindianpatents.com/patents/231047-a-process-for-the-preparation-of-polio-vaccine
• <1% – http://dictionary.sensagent.com/Polio%20vaccine/en-en/

Poliovirus and Polio Vaccines