Serum Institute of India is a manufacturer of immunobiological drugs including vaccines in India. It was founded by Cyrus Poonawalla in 1966.

The company is a subsidiary of the holding company Poonawalla Investment and Industries. The company is the world's largest vaccine producer by number of doses produced.

The company produces around 130 crore (1.3 billion) doses of vaccines each year. The products developed include tuberculosis vaccine Tubervac (BCG), Poliovac for poliomyelitis, and other vaccinations for the childhood vaccination schedule.

As of 2009, the institute developed an intranasal swine flu vaccine. In 2016, with support from US-based Mass Biologics of University of Massachusetts Medical School, it invented a fast-acting anti-rabies agent, Rabies Human Monoclonal Antibody (RMAb), also known as Rabishield.

According to en.wikipedia