Available Vaccines
Poliomyelitis
Introduction
Poliomyelitis is an acute communicable disease caused by one of the three poliovirus serotypes (poliovirus type 1, 2 or 3) and is spread mainly by the faecal-oral route. The last cases of wild poliovirus type 2 (WPV2) were reported in October 1999 (India) and global eradication of WPV2 was certified in 2015. The last case of wild poliovirus type 3 (WPV3) was reported in November 2012 (Nigeria) and global eradication of WPV3 was certified in 2019. In 2021, WPV type 1 (WPV1) cases were reported in Afghanistan and Pakistan. These two countries continue to report cases of wild poliovirus type 1 (polio-endemic countries). Besides these two countries, circulating vaccine-derived poliovirus (cVDPV) has been reported in 35 other countries in 2023 (for an updated list, visit 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 had confirmed that the vaccine-derived polioviruses (cVDPV1 and cVDPV2) were genetically linked to the virus circulating in the Philippines. However, after extensive public health measures, Malaysia was declared polio-free again since 11 Sept 2021.
On 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 associated paralytic poliomyelitis (VAPP) 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 reacquire biologic properties similar to naturally occurring wild-type poliovirus. This results in VAPP among the unvaccinated.
Vaccines
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 (bOPV) in the routine immunisation programme in countries with high risk of transmission. Type 2 poliovirus was removed from the vaccine because it was eradicated in 1999 and ongoing burden of VAPP due to circulating vaccine-derived poliovirus type 2. In November 2020, WHO recommended the use of type 2 novel oral poliovirus (nOPV2) in outbreaks due to circulating vaccine-derived poliovirus 2 (cVDPV2). The strains contained in the vaccine are modified versions of the original OPV strain with enhanced genetic stability.
IPV is the preferred strategy for polio prevention. In the event of supply limitations, practitioners should refer to current MOH circulars and NPRA updates. As of the end of 2022, no cases of acute poliomyelitis were reported.
Table 21.1 Vaccines Registered in Malaysia
*Imovax is no longer made available by Sanofi as the NPRA registration was not renewed since July 2025 due to negligible demand from the private sector. Need special import permits from MOH. Further detailed information may be obtained from (http://www.pharmacy.gov.my/v2/sites/default/files/
Table 21.2 High-Risk Groups in Malaysia
Implication for Health Care Workers (HCWs)
All healthcare workers should have completed a full course of primary vaccination
Evidence of Safety & Effectiveness
Contraindications and Adverse Effects
- Pregnant or breastfeeding women and immunocompromised persons can receive IPV only if they are at immediate risk of exposure.
- Reported adverse events include transient minor local erythema (0.5–1.5%), 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.
Evidence of effectiveness of IPV
IPV vaccine is highly effective in producing immunity to poliovirus and protection from paralytic poliomyelitis. Ninety percent or more of vaccine recipients develop protective antibody to all three poliovirus types after 2 doses, and at least 99% are immune following 3 doses.
References
- World Health Organization. (June 24, 2022). Polio vaccines: WHO position paper-June 2022. Weekly Epidemiological Record, 97(25), 277–300.
- Centers for Disease Control and Prevention.(August 2021). Poliomyelitis in Epidemiology and Prevention of Vaccine-Preventable Diseases. Hall E., Wodi A.P., Hamborsky J.,et al., eds. 14th ed. Washington, D.C. Public Health Foundation. Chapter 18: 275-287. https://www.cdc.gov/vccines/pubs/pinkbook/index.html
- Ministry of Health Malaysia (2023) Malaysia Health Facts 2022. Disease Control Division. https://www.moh.gov.my/moh/resources/Penerbitan/Penerbitan%20Utama/4._Health_Facts_2023-compressed_.pdf