Merck & Co., Inc. is a global healthcare company. The Company offers health solutions through its prescription medicines, vaccines, biologic therapies and animal health products. It operates through four segments: Pharmaceutical, Animal Health, Healthcare Services and Alliances. 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 its human health pharmaceutical products primarily to drug wholesalers and retailers, hospitals, government agencies and managed healthcare providers, such as health maintenance organizations, pharmacy benefit managers and other institutions. Vaccine products consist of preventive pediatric, adolescent and adult vaccines, primarily administered at physician offices.