Q&A: What do we know about the Moderna Covid-19 vaccine?

What do we know about the Moderna vaccine, and what gaps are there in the data?

A scientist working on the Moderna coronavirus vaccine (Screengrab/Moderna/PA)

US company Moderna has announced its coronavirus vaccine may be 94.5% effective against Covid-19.

The interim trial results come one week after Pfizer/BioNTech released early results for phase three of their vaccine study, suggesting their candidate has an efficacy of 90%.