Are there vaccines for these diseases?
Only yellow fever has a Food and Drug Administration–approved vaccine. There used to be one for Lyme too, called LYMErix, but it was taken off the market in 2002 after a scare about its side effects. Pharmaceutical companies are working on a replacement— as they also seek vaccines for Zika, West Nile, and others—but they haven’t yet succeeded. Scientists are trying all sorts of other methods to prevent bugs from spreading disease. In one study, researchers targeted ticks by tricking their hosts—deer and mice—into brushing up against materials containing anti-tick chemicals. For mosquitoes, the most promising technique appears to be flooding the target area with sterile or genetically modified males; then, when they mate, the females don’t produce viable offspring. But whether any of these tactics will work on a large scale remains to be seen. For now, people just have to be careful in high-risk areas: avoid walking in long grass, where ticks lie in wait to climb onto passing mammals; wear bug repellent and cover up as much skin as possible; and search for—and remove—ticks after spending time outside. “This is one concern in life that’s preventable by following some simple guidelines,” says David Weber, an epidemiologist at the University of North Carolina. “So it’s worth taking precautions.”