Become a registered user so you can access disease information and Merck product information, as well as complimentary resources for your practice.Enhance your experience with MerckVaccines.com. Become a direct-purchasing customer for all of your Merck vaccines. Plus, you will be able to review and track orders, pay invoices online, and manage inventory, at your convenience.If you currently order directly from Merck via phone, fax, or Sales Representative, then you can establish your online purchasing account here by linking your current Direct Purchase Account information to your MerckVaccines.com user account. Plus, you will be able to review and track orders, pay invoices online, and manage inventory, at your convenience.