SINOVAC Biotech Ltd. announced it received a drug registration approval from the NationalMedical Product Administration of China (“NMPA”) for its Sabin strain based inactivated polio vaccine (Vero cells) ("sIPV") on July 12, 2021. The vaccine is expected to be available on the market by the end of 2021. SINOVAC also submitted an application for prequalification (PQ) to the World Health Organization (“WHO”) in early 2020 and the WHO conducted its on-site inspection in February 2021. SINOVAC's sIPV is approved for use on infants and children aged 2 months and above to prevent poliomyelitis due to infection of types I, II and III polioviruses. The primary immunization requires 3 doses at least one month apart, beginning at 2 months of age. A booster shot will be given at 18 month of age. According to the results of phase III clinical trial, no serious or rare adverse events were observed in relation to vaccinations, which indicates the good safety profile of SINOVAC’s sIPV vaccine. Inactivated polio vaccine (IPV) contains no live virus and, thus, carries no risk of emergence from vaccine-derived poliovirus (VDPV) or vaccine-associated paralytic polio (VAPP). As the COVID-19 pandemic impact persists, countries where the wild polio strain still exist have been experiencing an increase in prevalence of polio casese. In addition, some other countries also reported more vaccine-derived poliovirus (VDPV) and vaccine-associated paralytic polio (VAPP) cases as a result of the virus circulating in the environment and human body, especially as the number of VAPP cases has reached a peak in the past 10 years.