Americans should be asking ourselves what else needs to happen before we can declare an end to the crisis phase of the pandemic. Although the coronavirus’s course remains unpredictable—and bad surprises are still possible—the Delta-variant surge that started in early July ushered in what may have been the final major wave of disease in the United States. The 1918 influenza pandemic ended only when enough Americans obtained immunity through infection to bring the pathogen under control. The U.S. may soon reach a similar point of controlling the coronavirus as well, both because of widespread vaccination and because of the immunity generated by the sheer volume of Delta infections.
Moreover, the country is also reaching one of the last major thresholds before a return to greater normalcy becomes possible. The FDA authorized COVID vaccines for 5-to-11-year-old American children last week; yesterday, a CDC advisory panel voted to recommend shots for this age group. These children are already at low risk of severe disease from COVID-19, but the risk is not zero, and the availability of vaccines for younger children will significantly ease parents’ anxieties. Immunity for elementary-school children will prevent severe disease later in life, and a vaccine for young children also impedes transmission to the more vulnerable. In another pivotal development, a soon-to-be-authorized oral antiviral treatment called molnupiravir will give doctors a major new treatment option. The drug inhibits viral replication, which should also limit transmission.
By now, Americans should realize that there isn’t a magic solution that will make COVID go away. Many restrictions, such as indoor mask mandates, remain in place to protect the vulnerable and unvaccinated in states following updated CDC COVID-prevention guidance. But within two or three months of introducing vaccines for 5-to-11-year-olds, the U.S. should be able to begin winding down most of the formal and informal limits to which Americans have become accustomed—office closures, masking mandates, educational interruptions, six-foot distancing, and more. (Data should be available soon on whether vaccines are safe for children ages 6 months to 4 years and how much of an immune response they provoke in this group. But children of this age are already at very low risk of COVID-19, and because most are not yet in school, their lack of access to vaccination is less disruptive to their family’s routines.)
COVID-19 is still causing more than 1,000 deaths a day in the United States; by comparison, influenza causes about 100 deaths a day on average, and most experts will feel uncomfortable declaring the coronavirus emergency phase over until COVID deaths settle down to a similar level. Yet infection, hospitalization, and death rates have begun to shrink since the peak of the Delta surge, and it’s not premature to begin planning for an end to the crisis phase. Once the emergency is over, Americans can focus on rebuilding their lives and think more clearly about how to accelerate COVID-19 vaccination abroad—a moral imperative that would also do far more than masks or booster shots for healthy, vaccinated U.S. adults would to end the global pandemic.
At this point in our pandemic, Americans should be explicit about the goals of our public-health policies. Immunity obtained through vaccination or infection can bring a pathogen to various states of containment: Eradication means reducing the worldwide level of a disease to zero, a level achieved only for a cattle virus and smallpox to date. Elimination means reducing the disease in a certain region to zero. Control means that a disease circulates only at low levels and causes minimal harm. This is the most realistic goal for dealing with the coronavirus. When the Alpha variant was dominant worldwide, some countries, such as Australia, New Zealand, and Singapore, still held out hope of elimination, but the highly transmissible Delta variant made this goal untenable and made high levels of vaccination even more essential for control. But while many experts have recognized that COVID will become endemic—that is, circulate at a low rate and never go away—few countries have explicitly accepted that reality and adjusted their policies and stated goals accordingly . One exception is Denmark, where more than 74 percent of people (and 80 percent of those older than 12) were fully vaccinated when the country dropped all remaining COVID-19 restrictions on September 10. Because immunity rates are so high, rates of severe disease have remained low since opening. Norway and Sweden also removed all remaining COVID restrictions at roughly similar vaccination rates.
In the United States, 65 percent of people over 12 had received at least one dose of a vaccine prior to the Delta surge; that rate is now 78 percent. That increase—about 12 percent of the 280 million Americans eligible to be vaccinated up to now—translates into 34 million new shots. Because the Delta variant is so transmissible, particularly to unvaccinated people, it has also produced higher rates of natural immunity. The U.S. has recorded at least 10 million new cases of COVID-19 during the Delta surge, which past experience suggests is almost certainly a significant underestimate. Many experts believe that 80 to 90 percent of the population needs to be vaccinated to bring Delta under control. But we may be approaching a comparable level of immunity now because of how many Americans have been vaccinated, survived COVID-19, or both.
That doesn’t mean the U.S. should stop encouraging people to get shots. If, as some research suggests, hybrid immunity is the most durable type of immunity, those with natural infection should be encouraged to get at least one dose of vaccine. Boosters are under way for certain vulnerable populations—as are second shots for those who received one dose of the Johnson & Johnson vaccine. A vaccine for 5-to-11-year-old children began shipping even before the CDC vote. But the high and rising immunity level in the population raises the question of how long emergency interventions other than vaccination will be justifiable or sustainable.
Masks, distancing, testing, contact tracing, ventilation, and moving activities outdoors were essential responses to the pandemic prior to the approval of vaccines and have persisted since. For a brief period, the CDC told vaccinated people they could take off their masks, but the Delta surge prompted the agency to encourage vaccinated people to mask again in many settings. States and communities applied that guidance to varying degrees, inadvertently setting up a series of natural experiments. A recent analysis indicated that high vaccination rates—not the reinstitution of mask mandates—in adjoining Southern California counties were the key to keeping cases and hospitalizations low. These findings spoke both to the power of immunity to control a pandemic and to the more limited impact of human behavior relative to increasing immunity. Cases, hospitalizations, and deaths have been falling across the U.S. since mid-September, with widely varying differences in remaining restrictions imposed by different states.
Although the course of the coronavirus pandemic has been difficult to predict over the past year and a half—and it could theoretically intensify yet again—countries with high rates of immunity that have lifted restrictions have not seen significant increases in severe disease yet. Viral evolution usually leads to more transmissible variants (such as Delta) but not necessarily more virulent ones or those that can evade our immune response. The U.S. still has more progress to make, but the reality is that the coronavirus is encountering fewer and fewer Americans who are defenseless against it.