1. Travel may increase the risk of acquiring Covid-19. Getting the vaccine lowers the odds that you’ll get Covid-19.
2. If you do get Covid-19 after the new immunization, it’s more likely to be a mild case.
3. After receiving the vaccine you’re less likely to get long Covid-19, a condition in which you have symptoms, often severe, for months or even years.
4. It’s a major drag to get sick when you’re traveling. You have to cancel activities, and it could delay your return home.
5. A lowered risk of getting Covid-19 means that you’re less likely to spread it to other people, including family members and vulnerable members of the population.

See
https://www.cdc.gov/coronavirus/2019-ncov/index.html
https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html