For the first time in 11 months, the daily average of new coronavirus infections in the United States has fallen below 30,000 amid continuing signs that most communities across the nation are emerging from the worst of the pandemic.
The seven-day average dipped to27,815 on Friday, the lowest since June 22 and less than a tenth of the infection rate during the winter surge, according to state health department data compiled by The Washington Post.
The pandemic map remains speckled with hot spots, including parts of the Deep South, the Rocky Mountains and the Pacific Northwest. At the local level, progress against the contagion has not been uniform as some communities struggle with inequities in vaccine distribution and in the health impacts of the virus.
But the vast bulk of the American landscape has turned pale green, the color-code for “low or moderate” viral burden, in a Covid-19 Community Profile Report released this week by the Biden administration. The report showed 694 counties still have “high” levels of transmission, less than half as many as in mid-April.
The big question now is whether the virus will be thoroughly squelched through mounting vaccinations - or whether it will smolder in areas with low inoculation rates and potentially flare when colder weather returns, said David Rubin, director of PolicyLab at Children’s Hospital of Philadelphia, which has been modeling the outbreak for more than a year.
Rubin said the answer will depend in large measure on the individual choices of tens of millions of Americans, especially whether they get inoculated.
“If we’re continuing to have disease reservoirs and we have areas with low vaccinations, it’ll hang on until the fall and start to pick up pace again. It’ll find pockets where there are unvaccinated individuals, and have these sporadic outbreaks,” Rubin said.
The group’s latest blog post states that “the national decline in case incidence is likely to be slow with a long tail, attributed to smoldering transmission - most likely from decreased mask use in areas with poor vaccine uptake.”
One prominent model, from the Institute for Health Metrics and Evaluation at the University of Washington, forecasts fewer than 7,000 daily cases by mid-August and fewer than 120 deaths, which is about one-fifth the current number - levels not seen since March 2020, soon after the virus first seeded itself in the United States.
The same modelers believe the virus will have some form of resurgence in the colder months that follow, and people who had stopped wearing masks would need to resume wearing them to limit viral spread. Scientists remain concerned about virus variants, some of which have mutations that limit but do not completely block the protective effects of vaccines.
“The rise in winter depends on what escape variants are circulating and how fast we pick up our masks and good behaviors,” Ali Mokdad, an epidemiologist with IHME, said in an email.
More than 60% of adults have had at least one shot of a vaccine, putting the country on a path of reaching President’s Joe Biden 70% target by July 4. Administration officials are increasingly confident the pandemic will be brought under control in the coming months, although infections will not plunge to zero and there remains the threat of mutated variants as the virus continues to circulate globally.
“I’m sure that we can control it,” Anthony Fauci, Biden’s chief medical adviser on the pandemic, told The Post. “Somewhere between control and elimination is where we’re going to wind up. Namely a very, very low level that isn’t a public health hazard that doesn’t disrupt society.”
In a separate, live-streamed interview with The Post, Fauci said it is too soon to know if and when people who have been vaccinated might need a booster shot.
“We may not need it for quite a while,” he said.
Most modelers are wary of making projections about epidemics beyond about four weeks, because there are so many variables in the equations. Human behavior is prominent among them. Mokdad said he is worried that, as mask mandates and restrictions on gatherings are lifted, people will be more reckless about transmission: “We should not relax prematurely.”
Infectious-disease experts have downplayed the significance of “herd immunity,” the threshold at which new infections are unlikely to lead to protracted chains of transmission. No one knows precisely where that threshold is and it is unlikely that every place in the country would achieve it.
Tens of millions of people remain unvaccinated and without prior infection, leaving them susceptible to the contagion. Vaccine hesitancy remains concerning enough that more states are offering huge cash giveaways, often via lottery, to prod people to get jabbed.
The encouraging statistical trends come even as experts debate the kind of metrics they should be monitoring, and as the supply of reliable numbers begins to get spottier. More than a dozen states no longer post daily coronavirus numbers on weekends. Testing has dropped across the country.
On May 1 the CDC halted its effort to monitor post-vaccination “breakthrough infections” that do not results in hospitalization or death. The agency’s website explained that the shift “will help maximize the quality of the data collected on cases of greatest clinical and public health importance.”
The new policy has drawn criticism from some public health experts, who worry the CDC may miss important signals embedded within the infections among asymptomatic or mildly symptomatic people who have been fully vaccinated.
Breakthrough infections are defined by the CDC as those that occur 14 or more days after a person has completed vaccination, which means either both doses of the Pfizer-BioNTech and Moderna vaccines, or a single dose of the Johnson & Johnson vaccine. These cases are rare. As of April 26, the CDC had documented just 9,245 among 95 million vaccinated Americans, although the agency acknowledged that the actual number is probably higher and simply hasn’t been documented through testing.
“By the CDC not doing this level of monitoring, it’s very reminiscent to me about how I felt in the Trump era: ‘You’re each on your own’,” said Kavita Patel, a primary care physician and nonresident fellow at the Brookings Institution. “What is the burden of collecting the information?”
If there is an argument that the effort outweighs the benefit, Patel said, “I haven’t heard it yet.”
Patel said she saw a breakthrough case this week, a woman with persistent itchy eyes, a sore throat and a bit of a cough who, she initially believed, was suffering from seasonal allergies. But a test confirmed the patient had covid-19 despite inoculation with the Johnson & Johnson vaccine.
Patel said she recommended that the woman isolate herself and rest, but will not recommend hospitalization unless her symptoms worsen.
Patel cites many reasons to monitor all breakthrough cases. At the most basic public health level, monitoring of all data for a disease can be critical. Covid-19 should be treated the same way, she said, to provide real-world evidence of how effective vaccines are. Continuing to show the public the rarity of breakthrough cases will buttress faith in the vaccines, she said.
When school begins, Patel added, unvaccinated children will be routinely mingling with vaccinated adults. Monitoring the impact of breakthrough cases among school staff also will be important, she said.
When asked at a media briefing Tuesday about the reasons for the data-monitoring change, CDC Director Rochelle Walensky said the “vaccines were studied to prevent severe illness, hospitalization and death, and as we look at these breakthrough infections, those are the ones we are most concerned about.”
Walensky also cited a technical issue: People with asymptomatic breakthrough infections often do not have enough virus in their bodies to permit genetic sequencing.
Many states, including Virginia and Maryland, as well as the District of Columbia, are continuing to gather this information. Vaccine producers also are collecting it as their clinical trials continue.
Eric Topol, a professor of molecular medicine at Scripps Research in San Diego, agreed with Walensky that asymptomatic breakthrough cases are not as important to follow. Nonetheless, he argued, the CDC should monitor those people, along with hospitalized and fatal cases, to determine whether and how virus variants might evade vaccine protection, help discover new variants and track how well certain vulnerable groups, such as the immunocompromised, are shielded by vaccines.
If there is a spreading event caused by an unvaccinated person spending a prolonged time indoors with vaccinated people, it will be important to investigate that as well, Topol said, even if no one is hospitalized or killed. Antibody levels may also wane over time, he noted.
Throughout the pandemic, one of the simplest metrics for tracking this health emergency has been the infection rate. How many people got infected today? Is that number going up or down or staying flat? Where are infections rising, and where are they falling? The infection numbers have always been leading indicators for what is to come in terms of hospitalizations and deaths. Death rates typically lag infection rates by at least three weeks and sometimes longer.
But it may be time to pay less attention to infections, and focus instead on people who become sick enough to be hospitalized or who succumb to covid-19, Fauci told The Post.
“The breakthrough infection number is not particularly relevant as long as they don’t spread the infection to anybody else,” he said. “If you are vaccinated and you do get a breakthrough infection, it is very likely that you will be without symptoms, and it is unlikely that you will transfer it to anybody else.”
He added, “The only number that you will absolutely be able to follow is the number of hospitalizations. . . . That might actually turn out to be the most reliable, followable parameter.”