There is this: https://www.ncbi.nlm.nih.gov/pubmed/20816312 https://www.ncbi.nlm.nih.gov/pubmed/20816312 "Compared to the 48 hours pre-exposure, participants

There is this: https://www.ncbi.nlm.nih.gov/pubmed/20816312 https://www.ncbi.nlm.nih.gov/pubmed/20816312 "Compared to the 48 hours pre-exposure, participants interacted with significantly more people, and in significantly larger groups, during the 48 hours immediately post-exposure [to a directly transmitted human pathogen-flu virus]."