SINOVAC is a biopharmaceutical company that has expertise in the research, development, manufacturing, and commercialization of vaccines that protect against human infectious diseases. It produces COVID-19, enterovirus71 (EV71), hepatitis A and B, seasonal influenza, 23-Valent pneumococcal polysaccharide (PPV), H5N1 pandemic influenza (avian flu), H1N1 influenza (swine flu), varicella and mumps, and other vaccines.