This paper looks at transmission through airborne, droplet and contact routes. It considers the evidence relating to time spent in an environment, distance to the source (2m rule), transmission on surfaces and ventilation as a mitigating factor. This paper is based on evidence available as at 26 April 2020.
The paper was originally discussed at SAGE meeting 29 on 28 April 2020. The paper was updated on 2 May 2020 to add an executive summary and amend the graph on page 10.
This evidence was often complied very rapidly during a fast-moving response and should be viewed in this context. The paper presented here is the best assessment of the evidence at the time of writing, and the conclusions were formed on this basis. As new evidence or data emerges, SAGE updates its advice accordingly. Therefore, some of the information in this paper may have been superseded at a later date.