Around the world, community, family and faith help physicians and medical advocates stay strong in the face of long hours and a relentless disease.

Successes for some balance setbacks for others. Meanwhile, viral outbreaks continue to claim lives across the globe — and a larger pandemic looms.

Worldwide, scientists test animals and their handlers for emerging viruses. In the U.S. and India, doctors work long hours caring for flu patients.

Anti-vaccine debate escalates, and medical staff are attacked in Congo. Funding cuts hit hard in the U.S., but researchers in Guatemala make strides.

Vaccine debates rage while health-care workers inoculate against the Ebola virus in Congo and influenza in detainee camps at the U.S.-Mexico border.

In this introduction to life on the front lines, doctors in the U.S. and Asia battle the flu, and researchers race to develop a universal vaccine.