From the document: 
 

This plan takes into consideration these key principles:

1. Ensuring staff and public safety is the first priority
2. Mitigating potential viral transmissions is the best method of ensuring that safety, as such
   the following information has to be considered:
   o COVID-19istransmittedprimarilythroughcontactwithinfecteddroplets o Asymptomaticindividualscanbeavectorforviraltransmission
   o Thereisemergingevidenceforlimitedaerosoltransmission
   (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7267124/)