The U.S. this year is set to have the worst outbreak of whooping cough since the 1970s. Already, from January to mid-July, there have been 17,000 registered cases and nine deaths.
Like the whoop that punctuates the cough, this number is a warning that something is very wrong. The increase, researchers suspect, is partly due to the waning effect of whooping cough vaccines introduced in the 1990s to replace older formulations. It’s also connected to the rising number of parents who refuse to get their children immunized because of a dangerously misinformed belief that vaccines are more harmful than the diseases they prevent.