What is Polio and Why Do I Need the Polio Vaccine?

Polio, or poliomyelitis, is a life-threatening virus that is most well-known for causing temporary or lifelong paralysis. While wild poliovirus type 2 and type 3 have been certified as eradicated, two nations still have an endemic spread of type 1 — Pakistan and Afghanistan^[2]. The last imported case of polio in America was in 1993, and the last case in Europe was in 2002 ^[3],[4].

Although polio is no longer a significant health threat, it is still important to continue vaccinating on schedule, as large pockets of unvaccinated people could cause the nearly extinct virus to start spreading again. It is recommended to get vaccinated against all three different types of polio, as having only one will make you immune to the specific type^[1].

How is polio transmitted?

Polio is a disease that is transmitted through person-to-person contact. The virus mainly replicates and lives in a person’s throat and intestinal tract. The disease primarily spreads through contact with the faecal matter of an infected person and can spread through droplets when coughing or sneezing^[3].

Therefore transmission modes are through contaminated water, food or an infected person not washing their hands well enough.

The virus can still spread during the two-week incubation time and even after many weeks of subsided symptoms. For example, the presence of the poliovirus is still found in the recovered person’s faecal matter^[3].

What are the symptoms of polio?

• Sore throat
• Fever
• Tiredness
• Nausea
• Headache
• Stomach pain

0.5% of people get lifelong paralysis. In some cases, polio is fatal due to the paralysis spreading to the muscles that support breathing^[3].

Long-term, some polio survivors experience ‘post-polio syndrome’ around 15 to 40 years after having polio. Post-polio syndrome isn’t life-threatening, but it can cause undesirable health problems like muscle weakness and atrophy, mental fatigue and joint pains^[8].

How can I avoid polio?

Although polio is a rare virus, it is still essential to ensure that your children are vaccinated against polio early. It is also recommended not to travel to countries with endemic spreads of polio without the vaccine.

Polio vaccine

1. Inactivated polio vaccine (IPV)
2. Oral polio vaccine (OPV)

Inactivated polio vaccine (IPV)

The oral polio vaccine gives an attenuated form of the virus which means it is much weaker than wild polio and stimulates a similar immune response to wild polio. The inactivated polio vaccine is taken via injection and can be administered with a concoction of other vaccines such as tetanus, diphtheria, pertussis, etc.

Adverse side effects from taking the inactivated polio vaccine are usually very mild^[12].

Oral polio vaccine (OPV)

OPV is taken orally. There are different types of OPV, which may contain one, a combination of two, or all three different serotypes. The OPV also mimics the immune response following infection with wild polioviruses, but with a reduced chance of the virus spreading to the central nervous system^[12].

At OT&P we recommend inactivated polio vaccine which is typically given in combination with other vaccines.

When should I get the polio vaccine?

If you don’t have the vaccine yet, it is vital to get it, especially when travelling to a country with cases of wild polio. Infants who have not had the polio vaccine yet are advised not to visit areas with high rates of polio until they can get vaccinated^[13].

Hong Kong’s Family Health Service recommends children get the three doses of the polio vaccine within the first years of their life (usually months 2,4, and 6). Then at about 18 months, an additional booster dose^[14].

When travelling to countries with known polio, the travel health service of Hong Kong recommends that you take an additional dose, even if you’re already fully vaccinated, to ensure safety against any wild strain of polio fully.

Speak to your doctor before travelling to ensure you get the correct vaccine schedule and immunise against vaccine-preventable diseases.

References

1. National Health Service. (2018). 'Polio'. NHS. 30 July 2018. Available at: <https://www.nhs.uk/conditions/polio/.> [Accessed 29 September 2021]
2. Centers for Disease Control and Prevention. (2021). 'CDC global health - Polio - our progress'. CDC. 19 March 2021. Available at: <https://www.cdc.gov/polio/progress/index.htm.> [Accessed 29 September 2021]
3. Centers for Disease Control and Prevention. (2021). 'Polio elimination in the United States'. CDC. 23 July 2021. Available at: <https://www.cdc.gov/polio/what-is-polio/polio-us.html.> [Accessed 29 September 2021]
4. European Centre for Disease Prevention and Control. (2019). 'Update on the global polio situation and implications for the EU/EEA'. ECDC. 6 December 2019. Available at: <https://www.ecdc.europa.eu/en/news-events/update-global-polio-situation-and-implications-eueea>. [Accessed 29 September 2021]
5. Centers for Disease Control and Prevention. (2020). 'World polio day 2020'. CDC. 21 October 2020. Available at: <https://www.cdc.gov/globalhealth/immunization/wpd/index.html>. [Accessed 29 September 2021]
6. World Health Organization. (2019). 'Poliomyelitis'. WHO. 22 July 2019. Available at: <https://www.who.int/news-room/fact-sheets/detail/poliomyelitis>. [Accessed 29 September 2021]
7. Johnson, S. (2018). 'Polio: Types, causes, & symptoms'. Healthline. 17 September 2018. Available at: <https://www.healthline.com/health/poliomyelitis>. [Accessed 29 September 2021]
8. Centers for Disease Control and Prevention. (2019). 'Post-polio syndrome'. CDC. 25 October 2019. Available at: <https://www.cdc.gov/polio/what-is-polio/pps.html> [Accessed 29 September 2021]
9. Bill & Melinda Gates Foundation. (n.d.). 'Polio'. Availabel at: <https://www.gatesfoundation.org/our-work/programs/global-development/polio>. [Accessed 29 September 2021]
10. World Health Organization. (2018). 'Poliomyelitis: Does polio still exist? Is it curable?'. WHO. 14 March 2018. Available at: <https://www.who.int/news-room/q-a-detail/does-polio-still-exist-is-it-curable>. [Accessed 29 September 2021]
11. Centers for Disease Control and Prevention. (2018). 'Polio vaccine effectiveness and duration of protection'. CDC. 4 May 2018. Available at: <https://www.cdc.gov/vaccines/vpd/polio/hcp/effectiveness-duration-protection.html.> [Accessed 29 September 2021]
12. World Health Organization. (n.d.). 'Poliomyelitis'. WHO. Available at: <https://www.who.int/teams/health-product-policy-and-standards/standards-and-specifications/vaccines-quality/poliomyelitis>. [Accessed 29 September 2021]
13. Travel Health Services. (2020). 'Poliomyelitis Vaccination'. Department of Health. 28 December 2020. Available at: <https://www.travelhealth.gov.hk/english/vaccine_prophylaxis/poliomyelitis.html>. [Accessed 29 September 2021]
14. Family Health Services. (2017). 'Inactivated Poliovirus Vaccine (IPV)'. Department of Health. July 2017. Available at:  <https://www.fhs.gov.hk/english/health_info/child/484.html>. [Accessed 29 September 2021]
15. World Health Organization. (2017). 'Poliomyelitis: Vaccine derived polio'. WHO. 19 April 2017. Available at: <https://www.who.int/news-room/q-a-detail/poliomyelitis-vaccine-derived-polio>. [Accessed 29 September 2021]