It’s not. Vaccine rates in the country you probably mean is higher than in the U.S. If you look at where there have been outbreaks you will notice they are not in low income areas. Think affluent, educated, white families who really are into eating organic and complain about big Pharma.
Think of low income levels engaged in the Head Start effort where required multiple vaxxes to infants before their systems are ready for them has already damaged or eliminated the very susceptible at a very early age. My cousin's newly graduated college-trained social worker daughter left the whole shebang with prejudice through what she saw in pedriatic abuse of the little ones while she was engaged in close personal administration of Head Start in the Southern Tier of New York State, which is rife with poverty-stricken welfare-leaning families.
There are vaccines for Tuberculosis (MDR-TB), Chagas Disease, Leprosy, and Dengue Fever?