Between the lines: Influenza is of particular concern for health officials, even though there are more contagious viruses — for example, measles — and more deadly ones, like Ebola.
Your pandemic flu shot may come in the mail
What's new: Scientists announced Wednesday they have successfully developed three key advances toward a possible pandemic flu vaccine — and it's one that could eventually be delivered to your doorstep via the mail, and be self-administered.
Why it matters: One of public health officials' greatest fears is another flu pandemic that could kill millions. It's not a question of if another one occurs, but rather when. Pandemics can kill large amounts of people worldwide. The largest influenza pandemic, known as the Spanish flu, occurred 100 years ago. It killed at least 50 million people.