The warming weather and longer days should also decrease transmission. In much of the world, summers have proved safer than winters during the pandemic, “apparently by virtue of how much time people spend outdoors, and how likely they are to keep windows open and have fresh air circulating,” says Saad Omer, a vaccinologist and the director of the Yale Institute for Global Health. Light and heat can kill the virus directly, but their main effect seems to be making the world more hospitable for us simply to go outside, be social, move our bodies, and improve our baseline levels of health.
Although most experts are hesitant to make concrete predictions about exactly when the U.S. can consider its outbreak over, personal plans can be revealing. Jha has famously been hoping to have a July 4 barbecue in his backyard, including 20 people. By August, he told me, he hopes to travel with his family. The pandemic expert and former assistant secretary of homeland security Juliette Kayyem told me much the same last month: “I have plans to travel abroad in August. I feel like the world will start to move well before then.”
Where exactly that world is going, however, is far from certain. A beautiful, COVID-free summer may be a vision of hope, and possibly a reality for many, but optimistic projections about the coming months in the U.S. can mean losing sight of a far more unsettling global picture. As things get better, the world could fall into the same patterns that got us to the point of nearly half a million American deaths. “I’m feeling generally optimistic for the U.S. this summer,” Omer says. “But I’m also having nightmares.”
Under no circumstances is the coronavirus simply going to disappear this summer. Cases will drop, and restrictions will lift in many places. But rather than an abrupt end to the pandemic, the coming months will be more like the beginning of an extended and still-volatile tail of the outbreak globally. What that will look like, and how long it will last, depends on how nations cooperate and coordinate—or fail to. Regardless of how quickly the immediate threat of viral illness subsides in the U.S., America’s choices in the coming weeks and months could mean the difference between a pandemic that ends this year and one that haunts everyone indefinitely.
Though Shaman’s projections about herd immunity may sound hopeful, the fact that the U.S. was able to identify such a small fraction of our cases is evidence of profound, persistent failures in detection, communication, and prevention. Rapid testing will be key to containing local outbreaks, especially next fall and winter. This infrastructure is not yet in place, nor do many Americans have easy access to high-quality masks. We also have a far-from-impeccable record of accepting lifesaving vaccines when they are on offer. Even assuming that almost everyone gets their shots as soon as possible, the Columbia researchers estimate that in the U.S. alone, roughly 29 million additional cases could occur between now and July, depending on how Americans decide to act and which restrictions states choose to lift. “We should really be redoubling our efforts to control the virus,” Shaman said.