Pfizer

Pfizer develops, manufactures and commercializes medicines and vaccines for patients worldwide. Its portfolio spans oncology, internal medicine, inflammation and immunology, and vaccines. Products include Prevnar pneumococcal conjugate vaccines, Comirnaty, an mRNA COVID-19 vaccine, and Eliquis for stroke prevention. Alongside drug discovery, Pfizer operates manufacturing and distribution infrastructure that brings treatments to healthcare systems across developed and emerging markets.

Cousins Charles Pfizer and Charles Erhart founded the company in Brooklyn in 1849. Albert Bourla, its chairman and CEO, has served as chief executive since 2019. An enduring engineering contribution was deep-tank fermentation, which Pfizer used to mass-produce penicillin in 1944. Today, its scientists use AI to help identify promising drug targets and molecules, while commercial teams use an AI planning platform to coordinate outreach to healthcare providers.

Acquisitions have expanded its research capabilities: the completed 2023 Seagen purchase, at approximately $43 billion in enterprise value, brought antibody-drug conjugate technology and cancer medicines. Pfizer also completed its Metsera acquisition in 2025 for approximately $7 billion in enterprise value plus milestone-contingent payments, adding investigational obesity therapies. Its established vaccine business illustrates its manufacturing scale: the company reported delivering its three-billionth Prevnar dose by the end of 2025, cumulatively across current and previous versions.