meadwestvaco corporation mwv 1.09, a global leader in packaging and packaging solutions, has received a grant to provide its medication event monitoring system mems&trade to the bill & melinda gates foundation. the system is being used in the foundation&39s new demonstration projects on preexposure prophylaxis prep medications to help prevent the spread of hivaids in subsaharan africa and india. the four studies launched in october 2014.orally administered prep medications represent an important tool in the efforts to eradicate hivaids worldwide.