Future COVID-19 vaccines might not have to be kept so cold A need for ultra-cold storage limits vaccine availability, but promising new solutions are on the horizon. ByMaya Wei-Haas Email The action was innocent: While cleaning the Veterans Affairs hospital in Boston this past January, a contractor knocked a loose freezer plug from its socket. This simple mistake resulted in the loss of nearly 2,000 doses of Moderna's COVID-19 vaccine that had been chilling inside the unplugged appliance. While that's a small hit on the grand scale of worldwide vaccination, it's emblematic of a much larger issue for many COVID-19 vaccines; they have to be kept frozen.