What stands between a flu that mostly affects pigs and a deadly virus that can jump from human to human? According to a new study, the barrier is only a few genetic tweaks.

Who is getting the message about getting the flu shot every year? A new study finds that in some cases, a racial line can be drawn between who gets vaccinated and who doesn't.

Getting a runner's high is the ultimate goal for marathon runners. But these runners can get a bit more than they asked for if they're not too careful.

Think back to the panic around swine flu in 2009, the first time H1N1 appeared on the scene. Did you think it was more deadly than the normal, run-of-the-mill flu?

The best thing a person can do to prevent the flu is to get a flu shot. Just that simple. And yes, getting the vaccine is especially important for children at higher risk of dying from the flu.

When California had the highest number of pertussis cases in six decades in 2010, public health officials took notice. Pertussis (whooping cough) is especially dangerous for babies.

There may be more to home field advantage than just familiar surroundings and local fans. Crossing a few time zones more than doubled some athletes’ sick days.

A day at the county fair is one of the hallmarks of summer in America. But you might want to skip the pig races this year: new swine flu cases have been linked to pigs at agricultural fairs.

Many people are prescribed antibiotics for acute respiratory infections, such as the common cold. But are the antibiotics prescribed doing more harm than good? 

Tweets about vaccines tend to carry strong opinions in 140 characters. If you follow a Twitter user who is against vaccination, what's the chance that you or your family won't get shots?