> 20-year-old Hungarian traveller

It’s weird that we require interventions that do have some documented risk to our own citizens so that foreigners can visit without restriction. If an illness is eradicated in our borders, why should we let in people who might have it? Odd tradeoff calculus.

Read up on herd immunity. The problem isn't specifically 'foreigners' but the general question of whether enough people are vaccinated to prevent the disease from roaring back when it inevitably - it is not possible to stop people from bringing diseases into the country - reoccurs.