Seoul, South KoreaThe COVID-19 testing center at H Plus Yangji Hospital in southern Seoul doesn't look like much from the outside. Resembling a mobile home, the temporary building sits in a parking lot near a loading ramp, propped up on one end by a wooden plank. Its walls are wrapped in red and white, and billboard-like signage proclaims that the hospital was named one of the 100 best in the Republic of Korea.

But inside is a gleaming bank of four booths with transparent plastic walls; rubber gloves embedded through them in a manner similar to a high-grade biosafety lab. When a person walks into a booth, they consult over an intercom with a doctor who remains outside. The doctor can swab