Poliomyelitis is an acute communicable disease caused by poliovirus and is spread mainly by the faecal-oral route. Of the 3 strains of wild poliovirus (type 1-3), wild poliovirus type 2 was eradicated in 1999 and no case of wild poliovirus type 3 has been reported since 2012. Only 2 countries in the world have never stopped transmission of polio (Pakistan and Afghanistan). These 2 countries continue to report cases of wild polio virus 1. Besides these 2 countries, circulating vaccine-derived polio virus (cVDPV) has been reported in 12 other countries in Africa, Eastern Mediterranean, South-East Asia and Western Pacific in 2020(www. polioeradication.org). In 2000, WHO certified Malaysia as polio-free. However, in December 2019, the Ministry of Health of Malaysia announced the country’s first case of polio since 1992. Testing has confirmed that the virus strain of poliovirus that is genetically linked to the virus circulating in the Philippines.
On an average, about 1 in 75 adults who are infected, will develop paralytic poliomyelitis. The case fatality rate among paralytic cases is higher in adults (15-30%) compared to children (5-10%) predominantly due to bulbar involvement. Outbreaks of vaccine derived poliomyelitis occur in regions with low immunisation rates and poor sanitation. The low immunisation rates result in long term circulation of the vaccine-derived poliovirus in the population and thus allowing the virus to mutate and acquire back biologic properties similar to naturally occurring wild-type poliovirus. This results in vaccine-associated paralytic poliomyelitis (VAPP) among the unvaccinated.
Two types of poliovirus vaccines are currently available: oral poliovirus vaccine (OPV) and inactivated poliovirus vaccine (IPV). Until 2015, over 90% of vaccine derived poliomyelitis were due to the type 2 component of OPV. In 2016 trivalent OPV was switched to bivalent OPV (type 2 polio virus was removed from the vaccine because it was eradicated in 1999) in the routine immunisation program in countries with high risk of transmission. In Malaysia OPV has been completely switched to IPV in the national immunisation program since 2010. IPV has mixture of inactivated, killed strains of all three poliovirus types.
Vaccines Available in Malaysia
1. Oral Poliomyelitis Vaccine® (Attenuated polio vaccine)
Propharm (M) Sdn Bhd/PT Bio Farma, Indonesia
2. Imovax Polio® (Inactivated polio vaccine)
Sanofi Aventis (Malaysia) Sdn Bhd/Sanofi Pasteur, France
IPV is also available in combination with DTP
Mode of Administration
- Inactivated poliovirus vaccine (IPV)
Adult dosage: 2 doses at an interval of two months. Booster to be given 8 to 12 months after the second injection.
Given into the deltoid muscle for intramuscular injection or the posterior aspect of the upper arm for subcutaneous injection.
Target Groups in Malaysia
- Travelers to polio-affected countries (refer to www.polioeradication.org for the list countries), who have previously received ≥3 doses of OPV or IPV, should be offered another dose of IPV as a once-only dose before departure.
- With the re-emergence of poliomyelitis in Sabah, Malaysians who wish to travel overseas to polio-free countries will need to check with the respective embassies if they require an additional single dose of IPV/OPV 4 weeks to 12 months prior to international travel.
- Residents or long term visitors (i.e., four weeks) from polio-affected countries need to receive one dose of IPV/OPV 4 weeks to 12 months prior to international travel.
- Healthcare workers, including laboratory personnel, who may have come in contact with people with polio or poliovirus need to receive a booster dose of IPV and if at ongoing risk receive the vaccine every 10 years.
- Refugees from countries where wild polio is still endemic and have not completed the required 3 doses of poliomyelitis vaccination should receive their remaining doses. It does not matter how long it has been since the last dose.
Unvaccinated adults whose children will be receiving oral poliovirus vaccine (for example, international adoptees or refugees) are higher risk individuals and may need 1 to 3 doses of IPV, depending on how many doses they have had in the past.
Unvaccinated higher risk individuals should get three doses of IPV; two doses separated by 1 to 2 months, and a third dose 6 to 12 months after the second dose.
Higher risk individuals who have had one or two doses of polio vaccine in the past should get the remaining one or two doses. It does not matter how long it has been since the earlier dose(s). Higher-risk adults who have had three or more doses of polio vaccine in the past may get a lifetime booster dose of IPV.
Contraindications and Adverse Events
In general, vaccination of pregnant women and immunocompromised persons should be avoided. However, if immediate protection is needed, IPV is recommended.
Reported adverse events include transient minor local erythema (0.5-1%), induration (3-11%), and tenderness (14-29%)
To date, the most frequently reported adverse event for OPV received by the National Pharmaceutical Regulatory Agency (NPRA) is fever. Cases of febrile seizure and convulsions had also been reported in children.
- The Malaysian National Centre of Adverse Drug Reactions Database [Accessed: October 10, 2019].
- National Pharmaceutical Regulatory Agency (NPRA), Ministry of Health Malaysia. Senarai Produk Vaksin Berdaftar Dengan Pihak Berkuasa Kawalan Dadah. Updated September 5, 2019.
- WHO (2016). Weekly Epidemiological Record, No 12, 25th March 2016; Polio vaccines; WHO position paper
- WHO (2019). Statement of the 20th IHR emergency Committee; Regarding the International Spread of Poliovirus.