With another vax reporting 95% efficacy, we may have multiple COVID-19 options

American biotech firm Moderna has released early results from its phase III clinical trials, announcing in a press release on Monday (US time) that its COVID-19 vaccine has an efficacy of 94.5%, according to an “interim analysis” by an independent data and safety monitoring board.

Here’s how the percentage was calculated.

First, there are two groups in the study: the