Liposome-Based Vaccine Formula Successfully Freeze-Dried

University of Buffalo scientists report that they have successfully freeze-dried a liposome-based liquid vaccine formula that could be developed for potential use in COVID-19 vaccines. A vaccine that employs the freeze-dried liposomes is still a long way off, they say, but if developed successfully, dehydrated doses could be shipped and stored at room temperature.

“At the time we started this project, the first COVID-19 vaccines were just getting rolled out, and there was a lot of news about how they needed ultra-cold storage, and how that was a huge logistical challenge. Especially in low- and middle-income countries, it may not always be feasible to have that type of refrigeration infrastructure. So we started to look at whether we could make a thermostable COVID-19 vaccine using a liposome-based vaccine platform that we worked on previously,” says Jonathan Lovell, senior author of the study published in Science Advances today.

The new study focuses on a liquid injection that consists of ingredients including water; specialized liposomes carrying a synthetically produced version of the spike protein of the COVID-19 virus; and a small amount of sugar, which helps to protect the formula during the freeze-drying process. The freeze-dried product looks a bit like cotton candy, mint green in color.

“Upon dehydration, the formula was stable at elevated temperatures, and we showed that it can withstand room temperatures and even higher temperatures for at least a week,” says first author Moustafa Mabrouk. “After that, we reconstituted the formula by adding water. When we tested this in mice, it induced effective antibody responses and offered protection against the COVID-19 virus.”