Pfizer's COVID-19 vaccine looks impressive, but Sanofi, J&J and Novavax shots eye a logistics edge

Pfizer's COVID-19 vaccine this week set high efficacy expectations, but the vaccine has stringent storage needs and requires two doses, creating significant challenges for a global vaccination campaign. If they prove themselves in the clinic, later-arriving shots from the likes of Sanofi, J&J and Novavax may be better suited for global distribution.