That is one of the (many) million dollar questions during this COVID-19 pandemic. Whatever the answer, public health recommendations to wear masks and keep distance from others are both necessary and precautionary as cases continue to rise in the United States. An excellent review of the science by Jayaweera et al. is found here: https://www.sciencedirect.com/science/article/pii/S0013935120307143?via%3Dihub. Conclusion: we need more research to understand the virus as well as to make evidence-based decisions around prevention.