In 2014, cross-sectional research on poliovirus seroprevalence in Guangdong was conducted, right before a change in polio vaccine began in 2015. For this study researchers wanted to see if polio immunity was strong enough to fulfill the polio vaccination switch. A total of 6339 persons had their poliovirus neutralizing antibodies tested (NA). Overall NA seropositivity for PV1, PV2, and PV3 was 95.2%, 94.9%, and 88.7%, respectively, with geometric mean titers (GMT) of 82.9, 55.8, and 26.3. The positive rates and GMT of the three serotypes differed statistically significantly, with PV3 having lower positive rates and GMT. The age group 1–9 years old had the greatest seropositivity and GMT. 

Positive NA and GMT rates for PV1, PV2, and PV3 were lower in the western area of Guangdong than in the other three regions. According to the findings of this study, the population of Guangdong province has a high degree of polio immunity, providing a strong foundation for a polio vaccine switch.