Warning: Hand sanitizers will not make you invincible. They don’t, for example, protect against germs like MRSA, as the FDA pointed out yesterday in a consumer update. Nor do they kill E. coli, salmonella, or the H1N1 virus. It’s not just consumers who don’t get this: The FDA yesterday fired off a round of warning letters to firms that falsely say their sanitizers fight MRSA, the Washington Post notes. In general, the CDC says, soap and water are preferable to sanitizers.