Today, I learned that much of the success of polio eradication in the Western hemisphere could be attributed to a vaccine delivery strategy employed throughout Central and South America. Between the 1960's-80's, a number of countries throughout the region started campaigns to immunize every child. Brazil specifically held a series of national immunization days, a strategy later adopted by other countries in the region. I'm not sure how many countries still actively maintain national immunization days or how effective they've been for diseases besides poliomyelitis. It's a bit disheartening to imagine the opposition such an approach would receive here in the US.