Defense secretary denies request to exempt Oklahoma National Guard from vaccine requirement

Defense Secretary Lloyd Austin on Monday denied a request by the Oklahoma governor to exempt members of the state's National Guard from the Defense Department's vaccine mandate. 

Austin told Oklahoma Governor Kevin Stitt that all members of the Defense Department's service branches must comply with the vaccine order or jeopardize their service.  

In a letter to Stitt, according to a copy obtained by CBS News, Austin said, "To maintain a healthy and ready military force capable of protecting the American people, the immediate vaccination against COVID-19 is an essential military readiness requirement for all components and units of the military, including the Oklahoma National Guard."