Pfizer Inc. and partner BioNTech SE plan to begin soon testing a freeze-dried version of its Covid-19 vaccine, which if proven to work safely could ease storage and handling of the shots in rural U.S. areas and low-income countries.

Pfizer Inc. and partner BioNTech SE plan to begin soon testing a freeze-dried version of its Covid-19 vaccine, which if proven to work safely could ease storage and handling of the shots in rural U.S. areas and low-income countries.