The dire need for safe and effective coronavirus disease (COVID-19) vaccines is met with many vaccine candidates being evaluated in pre-clinical and clinical studies. The COVID-19 vaccine candidates currently in phase 3 or phase 2/3 clinical trials as well as those that recently received emergency use authorization (EUA) from the United States Food and Drug Administration (FDA) and/or other regulatory agencies worldwide require either cold (i.e., 2-8°C) or even freezing temperatures as low as -70°C for storage and distribution. Thus, existing cold chain will struggle to support both the standard national immunization programs and COVID-19 vaccination. The requirement for cold chain is now a major challenge towards worldwide rapid mass vaccination against COVID-19. In this commentary, we stress that thermostabilizing technologies are available to enable cold chain-free vaccine storage and distribution, as well as potential needle-free vaccination. Significant efforts on thermostabilizing technologies must now be applied on next-generation COVID-19 vaccines for more cost-effective worldwide mass vaccination and COVID-19 eradication.
Keywords: Cold chain; Dry powder; SARS-CoV-2; Thermostability; Vaccine.