From the U.S. Chamber of Commerce:

You've likely heard that President Biden's vaccine mandate will take effect in the coming weeks and are wondering how it might impact your small business. The Department of Labor's Occupational Safety and Health Administration (OSHA) has developed an Emergency Temporary Standard (ETS) for employers with 100 or more employees, which mandates that employees must either receive CODI-19 vaccinations or produce weekly negative tests before coming to work in person. 

This video is a recording of the Small Business Update: The Latest on Employee Vaccine Mandates 

CO by U.S. Chamber of Commerce has compiled all the vaccine mandate facts and pared it down to what you need to know in this article.