Circulating vaccine-derived poliovirus type 2 (cVDPV2) – Indonesia – Indonesia

Sub Levels


Outbreak overview

On 17 March 2023, the Indonesian Ministry of Health informed WHO of the detection of circulating vaccine-derived poliovirus type 2 (cVDPV2) in a 48-month-old woman with acute flaccid paralysis (AFP) in Purwakarta District, West Java. I notified you. A field investigation was immediately initiated by local and national public health authorities with support from partners of the Global Polio Eradication Initiative (GPEI). Her 2 doses of novel OPV2 are planned to cover children under 5 years of age, regardless of previous vaccination status. The first round took place in April 2023 for her.

Occurrence Description

On 17 March 2023, the Indonesian Ministry of Health informed WHO of the detection of circulating vaccine-derived poliovirus type 2 (cVDPV2) in a 48-month-old woman with acute flaccid paralysis (AFP) in Purwakarta District, West Java. I notified you. This case developed paralysis on February 16, 2023. The girl had received no previous doses of oral poliovirus vaccine (OPV) or inactivated poliovirus vaccine (IPV). A stool sample was collected on 21 February 2023 and confirmed to be her cVDPV2 on 14 March 2023. Whole-genome sequencing results are pending. Her patient and her parents had no travel history within her 1 month prior to AFP onset. During this period, however, her family had visitors, including relatives, from another village.

Since November 2022, a total of 4 VDPV2-confirmed cases have been reported in Indonesia. This includes three cases of cyclic VDPV2 (cVDPV2) with acute flaccid paralysis (AFP) in Aceh and his one in West Java. Additionally, on 25 November 2022, her four healthy children in Aceh were confirmed to be infected with her cVDPV2. The poliovirus was identified as belonging to the same outbreak group as the cases reported in Aceh in 2022 and was therefore classified as cVDPV2, although it is distinct from Aceh virus. Indicates that there is a possibility of omission of transmission. A rapid risk assessment of the outbreak in Aceh in November 2022 was conducted and the risk was assessed as high at the national level, moderate at the regional level and low at the global level.

Administrative coverage of bivalent oral polio vaccine (bOPV4) in West Java province from 2018 to 2022 ranged from 88% to 102%, while that of inactivated polio vaccine (IPV) ranged from 26% to 106%. % range. The catch-up campaign in West Java also achieved over 90% vaccination coverage for bOPV and IPV. His bOPV coverage in Purwakarta district has been consistently high from 2018 to 2022, ranging from 94% in 2020 to 104% in 2021. However, IPV coverage will decrease to 26% in 2020, increase to 80% in 2021, and reach 100% in 2022.

However, pockets of unvaccinated children (either bOPV or IPV) remain in West Java. This is primarily due to a lack of parental understanding of the importance of vaccination, concerns about vaccine safety (as a result of post-vaccination fever, multiple injections, and other misinformation sources) and religious beliefs. .

Polio epidemiology

Polio is a highly contagious disease that primarily affects children under the age of five and causes permanent paralysis (about 1 in 200 infections) or death (2-10% of paralyzed people).

Viruses are transmitted from person to person primarily via the fecal-oral route, but less frequently via common fomites (such as contaminated water or food) and multiply in the intestine. and from there invade the nervous system and paralyze. The incubation period is usually 7-10 days, but can take 4-35 days. Up to 90% of infected people are asymptomatic or have mild symptoms, and the disease is usually not recognized.

Vaccine-derived poliovirus is a well-documented strain of poliovirus that has mutated from the strain originally contained in OPV. OPV contains a live, weakened form of poliovirus that replicates in the gut for a limited period of time, thereby developing immunity by building antibodies. In addition, OPV strains can be genetically altered and spread in poorly immunized polio-immunized communities, especially in areas with poor sanitation, poor sanitation and overcrowding. The lower the population’s immunity, the longer the virus survives and undergoes more genetic changes.

In very rare cases, vaccine-derived viruses can be genetically altered to a form that can cause paralysis, like wild poliovirus. This is known as vaccine-derived poliovirus (VDPV). ‘Circulating’ vaccine-derived poliovirus 2 if VDPV is detected in at least 2 different sources, at least 2 months apart, is genetically related, and shows evidence of community transmission. should be classified as type (cVDPV2).

Public health response

  • After confirmation of the case in West Java, a field investigation was completed by the Ministry of Health with the support of WHO, UNICEF and other partners. This includes an active survey of AFP patients in at least 200 households and a review of hospital records.
  • Faecal samples were collected from 30 healthy children, 6 of which were identified as VDPV2, confirming that the virus was already circulating.
  • Two doses of the new OPV2 are planned to vaccinate a total of 3,984,797 children aged 0-59 months in all 27 districts of West Java. The first round started on April 3, 2023. The first round on 11 April 2023 achieved a cumulative coverage of 85.6% in West Java. A second round is scheduled for his third week in May.
  • After the outbreak in Aceh on 25 November 2022, from 28 November 2022, two booster immunization activities (SIA) with nOPV2 for children aged 12 years and younger were held in Aceh province. first and second rounds.
  • SIA using nOPV2 started on 13 February 2023 in North Sumatra province adjacent to Aceh and is ongoing. Currently, the first consultation rate for 0 to 59 months is 93%. The total covered population of the two states combined is 2,564,594. This number meets the WHO-recommended minimum number target to be covered during SIA for cVDPV2 outbreak control.

WHO risk assessment

WHO has assessed the disease as high risk at the national level. Indonesia has a strong poliovirus outbreak response capacity and West Java has a moderate to strong outbreak response capacity to stop transmission, but after switching from trivalent to bivalent OPV, the population Highly susceptible to poliovirus type 2. Aceh, West Java, and some other provinces in Indonesia do not have optimal IPV coverage. High population migration between West Java and other provinces within Indonesia. Immunization resistance among at-risk populations. The outbreak in Indonesia is of moderate risk regionally and low risk globally.

Detection of cVDPV highlights the importance of maintaining high levels of routine immunization everywhere to minimize the risks and consequences of poliovirus spread and the importance of maintaining high levels of routine immunization everywhere, as well as the importance of high-quality vaccines for early detection of poliovirus. It emphasizes the need to ensure oversight.

WHO advice

Strengthen surveillance of AFP cases in all countries, especially those with frequent travel or contact with polio-affected countries or areas, to rapidly detect importation of new virus to facilitate rapid response. To do so, it is important to initiate a planned expansion of environmental monitoring. Countries, regions and regions should maintain uniformly high routine immunization coverage at the district level to minimize the impact of new virus introductions.

WHO’s International Travel and Health recommends that all travelers to polio-affected areas be fully vaccinated against polio.

According to the advice of the Emergency Committee convened under the International Health Regulations (2005), the international spread of poliovirus remains a Public Health Emergency of International Concern (PHEIC). Countries affected by poliovirus infection are subject to Temporary Recommendations. To comply with the Temporary Recommendations issued under the PHEIC, poliovirus-infected countries must: i) declare the outbreak as a national public health emergency; ii) Encourage residents and long-term residents to take IPV 4 weeks to 12 months before international travel iii) Residents and long-term residents 4 weeks to 12 months before international travel iv) and v) further strengthen efforts to increase IPV immunization coverage, including by sharing coverage data.

The latest epidemiological information on cVDPV is updated weekly.

WHO does not recommend any travel and/or trade restrictions to Indonesia based on the current information available regarding this event.

Further information

Quote source: World Health Organization (17 April 2023). Outbreak News; Vaccine-Derived Poliovirus Type 2 (cVDPV2) Outbreak – Indonesia. Available at https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON458



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