Drugmakers are turning to their Ebola and HIV playbooks as they race to fight the Wuhan coronavirus. Here's how 6 top firms are tackling a contagion that's already killed 1,800.

· As the coronavirus outbreak has exploded into a global public-health emergency, leading drugmakers have begun researching treatments and vaccines to stop the virus. 
· Johnson & Johnson, Sanofi, and GlaxoSmithKline are in the early stages of advancing vaccine candidates. The biotech Gilead is running trials to test an Ebola...