27 February

If you don't know about measles, it's super-hyper-infectious. Each person with it can infect up to 18 others. And it can wipe your immune memory clean, if you do get it, so that for 2-3 years you'll have as good as no strong protection against any infection. You'll be like a newborn baby. It also can kill or seriously injure even healthy people. If you haven't had measles or been vaccinated against it, I'd suggest doing that right now.