COVID-19 Among 18- to 22-Year-Olds as Campuses Reopened, August–September 2020

Young adults are less likely than older people to become severely ill with COVID-19, but they can still get seriously sick — even mild or silent infections can lead to problems such as heart inflammation — and they can pass the virus to people at higher risk. About 45% of Americans aged 18–22 were enrolled in college in 2019, so as campuses reopened in 2020, CDC looked at what was happening in that age group.

Cases rose sharply in August

From August 2 to September 5, 2020, CDC received case reports for 999,579 people with COVID-19, 15.6% of them aged 18–22.

In the Northeast, every other age group had stayed below 53 weekly cases per 100,000 since July 4. Nationally, the share of all weekly cases that were among 18- to 22-year-olds roughly doubled (2.1-fold), from 10.5% to 22.5%.

Weekly COVID-19 incidence by age group, May 31–September 5, 2020. CDC

Testing rose too — but not enough to explain it

Their share of all tests grew from 9.4% to 14.4% (1.5-fold) — less than the rise in their share of cases. New screening as colleges reopened probably drove some testing, and more testing likely explains part of the rise in cases — but not all of it.

Weekly SARS-CoV-2 RT-PCR test volume and share of tests by age group, May 31–September 5, 2020. CDC

A shift by race and ethnicity

Among white 18- to 22-year-olds, weekly incidence rose 149.7%, from 48 to 120 per 100,000, while it held steady or fell in other racial and ethnic groups. The white share of cases in this age group climbed from 33.8% at the start of June to 77.3% by early September. The biggest rises among white young adults were in the Midwest (198.2%, from 65 to 195 per 100,000) and Northeast (168.4%, from 14 to 37).

Weekly COVID-19 incidence among 18- to 22-year-olds by race and ethnicity, May 31–September 5, 2020. CDC

Why

Many things may be behind the rise, including changes in behavior and in social, economic and policy conditions. But about 45% of 18- to 22-year-olds attend college, and 55% of them are white, so part of the increase is likely linked to the return of in-person classes. Detailed exposure information from young patients would help pin down the drivers.

Why it matters beyond campus

Earlier studies found young adults less likely to follow some prevention measures. And they don't live in isolation: about 71% of 18- to 22-year-olds live with a parent, and 33% live with a parent while enrolled in college. Spread among young people can reach households and communities — including people at high risk because of age or health conditions.

What the authors urge:

• Students, faculty and staff should stay vigilant and take steps to cut transmission on campus.
• Young adults, in college or not, should wear masks, keep their distance, wash their hands and follow local, state and federal guidance; targeted messages, such as social media toolkits, can help.
• Colleges and universities should act to keep their environments healthy.

Limits

Race and ethnicity were recorded for only half of cases, and completeness changed over time. Reporting lags delay trends. A revised case definition of August 5, adopted gradually by about half of jurisdictions, may have added variability. Case and testing data can't be linked at the person level, and patterns such as repeated testing of all students at some universities complicate interpretation.

Sources

Based on Salvatore PP, Sula E, Coyle JP, et al., "Recent Increase in COVID-19 Cases Reported Among Adults Aged 18–22 Years — United States, May 31–September 5, 2020," MMWR volume 69, number 39, Centers for Disease Control and Prevention, posted as an Early Release on September 29, 2020; a work of the United States government in the public domain. The report's discussion describes incidence as changing "2.1-fold," but its results give a 55% rise in incidence and a 2.1-fold rise in the age group's share of cases; the results are used here.