Merck & Co., Inc. is a health care company, which engages in the provision of health solutions through its prescription medicines, vaccines, biologic therapies, animal health, and consumer care products. The company is headquartered in Rahway, New Jersey and currently employs 75,000 full-time employees. Its Pharmaceutical segment includes human health pharmaceutical and vaccine products. The firm sells its human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed health care providers. The company sells these human health vaccines primarily to physicians, wholesalers, distributors and government entities. Its Animal Health segment discovers, develops, manufactures and markets a range of veterinary pharmaceutical and vaccine products, as well as health management solutions and services, for the prevention, treatment and control of disease in all livestock and companion animal species. Its products include KEYTRUDA (pembrolizumab) injection, for intravenous use; WELIREG (belzutifan) tablets, for oral use; Ohtuvayre (ensifentrine) and others.