PATH said it received two Grand Challenges Explorations grants from the Gates Foundation to explore new ways to deliver and manage vaccine supplies. Each winning proposal receives US$100,000. The first grant supports a PATH project to advance the development of a protective liner for vaccine carriers. The liner is prefilled with a newly developed material derived from biomass known as an engineered phase-change material. It can prevent vaccines from freezing during transport to remote locations while also extending the cooling capacity of vaccine carriers. The low-cost liner will use the novel phase-change material to protect vaccines from temperature extremes. The nontoxic material helps stabilize the temperature inside the carrier as frozen ice packs gradually warm, buffering vaccines from freezing temperatures. The liner can be retrofitted for use in existing carriers. PATH will work with companies that make vaccine carriers to conduct lab and field tests and develop product specifications that can be shared broadly with manufacturers. The second grant-funded project will assess the feasibility of using bar code technology to improve vaccine inventory management and supply forecasting when introducing new vaccines in low-income countries.