As Covid-19 cases increase among young adults in the United States, older adults are likely to contract the novel coronavirus, recent CDC reports suggest.
Covid-19 cases surge among young adults, new CDC data shows
At the beginning of the country's coronavirus epidemic, older adults had the highest rates of Covid-19, but new data from CDC's Morbidity and Mortality Weekly Reports (MMWRs) shows younger adults now account for the largest share of confirmed Covid-19 cases in the United States.
According to a CDC report released Tuesday, weekly Covid-19 cases increased by 55.1% nationally among young adults ages 18 to 22 from Aug. 2 through Sept. 5. Data from the report—which examined probable and confirmed Covid-19 cases from 50 states, Washington D.C., and four U.S. territories—showed the largest increases in Covid-19 cases among young adults occurred in the Northeast and Midwest, where weekly Covid-19 cases rose by 144% and 123%, respectively.
The researchers also found the weekly incidence of Covid-19 among white adults ages 18 to 22 increased by 149.7% from 48 per 100,000 on Aug. 2 to 120 per 100,000 on Sept. 5, but declined or remained stable among other racial and ethnic minority groups.
Although the number of weekly coronavirus tests conducted among young adults ages 18 to 22 increased from 1,877 tests per 100,000 during the week ending on Aug. 8 to 2,802 tests per 100,000 during the week ending on Sept. 5, the researchers found the spikes in Covid-19 cases could not be solely attributed to increased coronavirus testing.
The researchers wrote that multiple factors—"including changes in behavior or risk profiles resulting from multiple social, economic, and public policy changes during this period"—likely sparked the surge in Covid-19 cases among young adults. For example, the researchers wrote, "Previous reports identified young adults as being less likely than are other age groups to adhere to some Covid-19 prevention measures, which places them and their close contacts at higher risk for Covid-19."
In addition, the researchers noted that "[b]ecause approximately 45% of persons aged 18–22 years attend colleges and universities and 55% of those attending identified as white persons, it is likely that some of this increase is linked to resumption of in-person attendance at some colleges and universities."
According to a separate CDC report released on Tuesday, a North Carolina university saw a rapid increase in Covid-19 cases and clusters within two weeks of the university reopening for students. Specifically, the researchers found the university had 670 laboratory-confirmed cases of Covid-19 from Aug. 3 to Aug. 25, with 96% of cases occurring among adults younger than 22. The researchers also found 18 "clusters of five or more epidemiologically linked cases within 14 days of one another were reported."
The researchers wrote that, "Student gatherings and congregate living settings, both on and off campus, likely contributed to the rapid spread of Covid-19 in this setting."
What spikes in Covid-19 cases among young adults means for community transmission
As the number of Covid-19 cases among young adults increased over the past few months, the age distribution shifted—with the national median age of people with Covid-19 cases decreasing from 46 years old in May to 37 years old in July, according to a CDC report released last week.
As of August, adults ages 20 to 29 accounted for the largest share of confirmed Covid-19 cases in the United States, the researchers found.
However, the epidemic's age distribution could change again, the report suggested. When the researchers examined Covid-19 outbreaks in the southern United States in June, they found "increases in the percentage of positive [new coronavirus] test results among adults age[s] 20 [to] 39 years preceded increases among adults [60 and older] by an average of 8.7 days … , suggesting that younger adults likely contributed to community transmission of Covid-19."
According to NPR's "Shots," CDC's findings appear to confirm what many public health experts had long predicted: Covid-19 cases among young adults lead to cases among older people who are at risk of severe cases of the disease.
Tom Inglesby, director of the Center for Health Security at Johns Hopkins Bloomberg School of Public Health, said, "This is what we worried would happen if young adults started regathering in higher numbers. We need to turn this around. Leaders need to communicate better with younger people how essential they are in keeping this epidemic under control." He added that the CDC's findings provide "more evidence that the concept proposed by some—cocoon the elderly, and let young people get sick because they will not have bad outcomes—will not work."
Tegan Boehmer, an epidemiologist and the lead author of the CDC's report, said her message "to younger adults is to understand that they may play a role in the transmission of Covid-19 to family and friends and others in their communities, and they play an important role in our ability to contain the [epidemic]." According to Boehmer, because young adults experience more mild cases of Covid-19, they may "be in a situation where [they] don't know that [they are] infectious or that [they are] contagious," particularly before they develop Covid-19 symptoms. "There's the possibility that they're unknowingly transmitting Covid to others during this pre-symptomatic or asymptomatic state," she added.
However, there are steps being taken to curb the coronavirus' transmission among young adults.
For example, a local public health department in San Francisco is hoping to convince young adults to take precautions against the new coronavirus by launching a new Covid-19 Youth Ambassador Program. Under the program, a group of popular social media stars act as Covid-19 "influencers," according to "Shots."
"These young people are our football stars, they are makeup artists, they're on YouTube, they're fashionistas," Ryyn Schumacher—a program manager at Contra Costa Health Services, which recently launched the Youth Ambassador Program—said. He added, "We don't spoon-feed the message to our young people. … We ask how are you protecting your grandma from Covid? And they may want to talk about their grandma and how she makes the best menudo" (Stone, "Shots," NPR, 9/29; Rabin, New York Times, 9/24; Hellmann, The Hill, 9/29; Walker, MedPage Today, 9/29; CDC MMWR, 9/23; CDC MMWR , 9/29; CDC MMWR , 9/29).