June 21, 2019, Roland Walter Sutter, Coordinator, Office of Polio Eradication, World Health Organization, Carolyn Sein, Technical Officer, Office of Polio Eradication, World Health Organization, Mark Steven Oberste, Head of Polio Lab, US Centers for Disease Control, World Health Organization China Senior officials Zuo Shuyan and his entourage visited Minhai. General manager Zheng Haifa and other senior executives extended a warm welcome to the World Health Organization and his delegation.

　　The visiting experts affirmed the progress of Minhai Biological's sIPV project, and encouraged Minhai to speed up the clinical, registration and WHO pre-certification progress of sIPV, to be listed in China as soon as possible, and to UNICEF after passing the WHO pre-certification And other institutions.