After initiating its own wastewater testing for polio last year, Canada has detected two samples of vaccine-derived polio virus type 2 (VDPV2). According to the World Health Organization (WHO) and Pan American Health Organization (PAHO)'s epidemiological update released on Dec. 30, 2022, the virus strain was found in two wastewater samples collected between Aug. 20 and Aug. 30 2022.