Merck & Co., Inc. is a global healthcare company. The Company offers health solutions through its prescription medicines, vaccines, biologic therapies and animal health products, which it markets directly and through its joint ventures. It operates through one segment, Pharmaceutical. The Company's Pharmaceutical segment includes human health pharmaceutical and vaccine products marketed either directly by the Company or through joint ventures. Human health pharmaceutical products consist of therapeutic and preventive agents, generally sold by prescription, for the treatment of human disorders. The Company sells these human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed healthcare providers. The Animal Health segment discovers, develops, manufactures and markets animal health products, including vaccines. The Company's animal health products are sold to veterinarians, distributors and animal producers.