No he/she does not. So long as he has anti-bodies running around in body, not likely to die from extreme covid sickness.
However in some situations, such as boarding a cruise ship, there is a limited time between when boarding starts and the ship sails. And they must check in thousands of passengers in that limited time. They check your ID, register your credit card, issue you a cruise card, etc. Now we have the covid pandemic situation going around. A vaccination document check is quick. To perform an anti-body test is neither quick or inexpensive. So it makes practical sense to require vaccination documents.
We don’t have a pandemic. We have an act of biological warfare that is 99.8% survivable. The average age of the dead is 80, median age 78, most obese with comorbidities.
I pray to God that the Chinese torture you to death in appreciation for your aid in helping them take over the USA.