Final answer:
The US flag is generally flown at half-staff for 10 days after the death of a vice president, per standard US flag protocol not detailed in the provided resources.
Step-by-step explanation:
The information provided does not specify the length of time the US flag is flown at half-staff after the death of a vice president. Instead, the provided information discusses the procedures outlined in the 25th Amendment concerning presidential succession and disability, as well as other details related to the powers of the vice president when the president is deemed unable to fulfill their duties. However, according to standard US flag protocol not stated in the resources provided, the US flag is typically flown at half-staff for 10 days following the death of a vice president.