Breakthrough infections: What they’re telling us
With the highly contagious Delta variant sweeping across the U.S., vaccinated Americans feel growing concern about “an apparent rise in so-called breakthrough infections,” said Denise Chow in NBCNews.com. Over 150 vaccinated Fourth of July revelers in Provincetown, Mass., tested positive, the New York Yankees reported “multiple confirmed breakthrough cases,” and infections were reported in a vaccinated White House staffer. Breakthrough cases are indeed rising as overall case counts spike, but health officials say that doesn’t mean vaccines are failing. In fact, they’re performing remarkably well, drastically cutting infection rates and deaths and rendering “the vast majority of breakthrough cases” mild or asymptomatic. Severe breakthrough illnesses are “exceedingly” rare, said Emily Sohn in NationalGeographic.com. As of July 19, the CDC counted just under 6,000 among more than 161 million fully vaccinated Americans—a “rate of less than 0.004 percent.”
Much remains unknown, said Selena SimmonsDuffin and Rob Stein in NPR.org. Asymptomatic breakthrough infections aren’t usually detected, so we have no idea how widespread they are. Vaccinated people who have been exposed to the infection generally carry a lower viral load in their noses, but the CDC says that in “rare cases,” they can infect others. It’s also unclear whether breakthrough cases can lead to the misery of long Covid, but infectious disease expert Monica Gandhi says that long Covid is linked to a “dysregulated inflammatory response” that vaccines should prevent.
To understand breakthrough infections, said Katherine Wu in TheAtlantic.com, “think of the human body as a castle” and the immune system as its defenders. The unvaccinated have a “flimsy” line of defense that’s easily breached. The vaccinated have waves of defenders that have been trained to attack a “familiar foe.” Some attackers might still breach the wall, but “their ranks are fewer, weaker, and less damaging,” so Covid feels like the flu or a bad cold, rather than like a lifethreatening illness. Still, as Delta spreads, even the vaccinated need to rethink “our personal risk calculus,” said Susan Matthews in Slate.com. Should you go to a bar or indoor stadium or wedding unmasked? Factors influencing those decisions should include your health, risk tolerance, and local case counts. All this may feel confusing, but we’re entering a future “where Covid is something that we just have to live with.”