Lol we're already there. 2019 was the most cases the US has seen since the measles were declared eradicated in the country. New York and Washington declared an official state of emergency for it. This year is barely better and we are perilously close to losing its elimination status which would (obviously) make us the only developed nation to hold that honor.
Fun fact, this year 97% of cases were found in people that were not fully vaccinated. Of course this is merely a huge coincidence and vaccines serve no other purpose than turning us and the neighboring wildlife gay but it's worth noting.