Pfizer pilot takes on its COVID-19 vaccine's big problem

Pfizer is tackling one of the biggest potential headaches of its COVID-19 vaccine candidate, figuring out how it can distribute the drug while maintaining the strict low temperatures it demands. While the news earlier this month that the mRNA-based vaccine Pfizer co-developed with BioNTech was more than 90-percent effective in early trials received a warm welcome, its cold store requirements …