Developers need to test in hotspots, but those keep changing. And they must avoid ethical problems, like testing in low-income areas but only selling in rich ones.
MORE THAN 140 possibilities for making a vaccine against Covid-19 are being studied around the world. The vast majority of them are still just concepts in a lab, but more than a dozen have been injected into humans, mostly in small-scale trials to make sure each formula is safe to receive. Three are headed toward large human trials this summer, and a surprise announcement on Monday revealed that China is allowing military use of one vaccine being developed there.
That pace, faster than any vaccine has ever been produced, is intended to satisfy the US federal government’s goal of delivering a safe and potent vaccine by January. But as developers race toward broad testing, they are about to crash into a complication: the patchwork nature of the pandemic across the United States.
In order to know whether a vaccine works as intended, you have to pick your test site with care: There has to be enough virus circulating there to create a reasonable chance that vaccinated trial participants will be exposed to it. But even though the United States’ case count keeps heading upward, with 2.68 million cases as of Tuesday, the pandemic isn’t uniformly distributed across the country.
