Concurrent outbreaks of circulating vaccine-derived poliovirus types 1 and 2 affecting the Republic of the Philippines and Malaysia, 2019–2021
Cynthia J. Snider, Liliane Boualam, Graham Tallis, Yoshihiro Takashima, Rabindra Abeyasinghe, Ying-Ru Lo, Varja Grabovac, Tigran Avagyan, Syeda Kanwal Aslam, Abu Obeida Eltayeb, Khin Devi Aung, Xiaojun Wang, Achyut Shrestha, Carla Ante-Orozco, Maria Wilda T. Silva, Nemia Lapastora-Sucaldito, Lea Necitas G. Apostol, Muhammad Bin Hj. Jikal, Waheed Miraj, Faisal Rashid Lodhi, Hyung Joon Kim, Norhayati Rusli, Bruce Thorley, Matthew B Kaye, Yorihiro Nishimura, Minetaro Arita, Jamiatul Aida Md Sani, Christina Rundi, Keith Feldon
Abstract
Concurrent outbreaks of circulating vaccine-derived poliovirus serotypes 1 and 2 (cVDPV1, cVDPV2) were confirmed in the Republic of the Philippines in September 2019 and were subsequently confirmed in Malaysia by early 2020. There is continuous population subgroup movement in specific geographies between the two countries. Outbreak response efforts focused on sequential supplemental immunization activities with monovalent Sabin strain oral poliovirus vaccine type 2 (mOPV2) and bivalent oral poliovirus vaccines (bOPV, containing Sabin strain types 1 and 3) as well as activities to enhance poliovirus surveillance sensitivity to detect virus circulation. A total of six cVDPV1 cases, 13 cVDPV2 cases, and one immunodeficiency-associated vaccine-derived poliovirus type 2 case were detected, and there were 35 cVDPV1 and 31 cVDPV2 isolates from environmental surveillance sewage collection sites. No further cVDPV1 or cVDPV2 have been detected in either country since March 2020. Response efforts in both countries encountered challenges, particularly those caused by the global COVID-19 pandemic. Important lessons were identified and could be useful for other countries that experience outbreaks of concurrent cVDPV serotypes.