Using frozen saltwater packs for short-term transport of vaccines at -25°C to -15°C

Overview

Some of the earliest COVID-19 vaccines deployed during the pandemic had a shorter shelf life at +2°C to +8°C. Therefore, transporting these vaccines in a frozen state is the most viable option to maintain their potency throughout the delivery period. This allows the vaccines to be stored in freezers at the lowest distribution points, extending their shelf life at –25°C to –15°C. However, using regular frozen water packs for transport poses challenges, especially for distant facilities, as these packs can only maintain the –25°C to –15°C range for a limited time. To provide countries with a practical interim solution for effectively transporting vaccines at –25°C to –15°C, the World Health Organization (WHO), in collaboration with PATH, developed guidance on using frozen saltwater packs. This minimally validated protocol is designed for certain COVID-19 vaccines or other emergency-use vaccines that require similar temperature conditions during transport. It is not intended for routine use and should only be employed when no other viable transportation methods are available to maintain the –25°C to –15°C temperature range.