What should a Brazilian traveler do if denied entry into Thailand due to lack of yellow fever vaccination?

A traveler with a Brazilian passport arriving in Thailand was initially denied entry due to not possessing a yellow fever vaccination. The discussion revealed that travelers from yellow fever-infected areas, including Brazil, must have an International Health Certificate as proof of vaccination to enter Thailand. Several options were suggested, including showing proof of residence in the U.S. where the vaccination may not be required, or seeking a vaccination at a local hospital. Ultimately, the traveler was allowed entry, indicating that communication with immigration can be pivotal.