RNA vaccines still outshine other modalities as two protein-based COVID-19 vaccines yield mixed results 

With clinical data available from at least four vaccine modalities, including validated technologies, results from the newest modality — mRNA — remain the strongest. 

mRNA vaccine technology, which the U.S.’s Defense Research Advanced Projects Agency (DARPA) placed early bets on years ago for its promise to respond rapidly to viral outbreaks, generated the first candidates to enter late-stage testing for COVID-19, and to date, their results remain the most impressive...