Total lot release volume of polio vaccines in China 2017-2022
In 2022, over 63 million doses of polio vaccines were released in China, representing a rise of more than 25 percent from the previous year. The majority of the vaccines released were oral polio vaccines (OPV), in which live viruses were retained. As attenuated vaccines can cause adverse side effects and even result in vaccine-associated paralytic poliomyelitis (VAPP), inactivated vaccines are usually administered before the oral vaccines, thus reducing the risk of side effects.
