One year after the first cases of a novel coronavirus emerged in Wuhan, a team from the World Health Organization has arrived in the city to investigate its origin. Meanwhile, mixed results are reported for some of the leading Chinese vaccines being developed to fight the pandemic still wreaking global havoc.

US vaccination campaign will pick up speed now that access is broadening, leaders from Operation Warp Speed, Pfizer, Moderna, McKesson and CVS Health say at a J.P. Morgan panel discussion.

Development of vaccines usually takes years, but drug makers whittled the process down to a matter of months amid a concerted response to a global health threat.

The Chinese company is enrolling an additional 10,000-20,000 people in its late-stage coronavirus vaccine study focusing on older and sicker patients.