Childhood vaccination rates against measles fell in the years after the COVID-19 pandemic in nearly 80% of the more than 2,000 U.S. counties with available data — including in states that are battling outbreaks this year. A Johns Hopkins University study, published in JAMA this week, illustrates where more vulnerable communities are located. The results mirror trends established at state and national levels: Routine childhood vaccination rates are dropping. “When you look at the state level or national level … you really don’t see those drastic drops. Those are there. They’re real and they’re really problematic,” said Lauren Gardner, an…