Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Denver news in your inbox

Catch up on the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Des Moines news in your inbox

Catch up on the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Minneapolis-St. Paul news in your inbox

Catch up on the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tampa Bay news in your inbox

Catch up on the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Charlotte news in your inbox

Catch up on the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Photo: Faris Hadziq/SOPA Images/LightRocket via Getty Images

Increasing the number of coronavirus tests performed relative to a country's caseload was the strategy most associated with reducing the transmission rate of the virus, according to a new study published in Health Affairs.

Yes, but: The U.S. overall had a low testing intensity between March and June, which means that "testing mostly diagnosed and isolated the most symptomatic cases, which has limited impact on transmission."

  • Even though we're now doing more than a million tests a day, it's not enough to keep up with our ever-rising caseloads.

Details: A tenfold increase in the ratio of tests to new cases reduced average transmission by 9%, the study found.

Between the lines: "Around half or more of COVID-19 transmission is caused by people who are asymptomatic or who have only minor symptoms, so only increases in PCR testing make it possible to increase detection and isolation of infectious cases, and then to increase the numbers of their potentially infectious contacts who are isolated," the authors write.

  • "This remains the only known approach that blocks person-to-person transmission sufficiently to stop the epidemic."

Bonus: The study also found that "being a US territory was also significantly associated with a 12.7% ... increase in transmissibility compared to the rest of the world."

Go deeper

Jan 20, 2021 - Health

California Rep. Raul Ruiz contracts COVID-19

Photo: Greg Nash-Pool via Getty

Rep. Raul Ruiz (D-Calif.) tweeted Tuesday that he has tested positive for the coronavirus.

Why it matters: He is the latest member of Congress to contract the disease since pro-Trump rioters stormed the U.S. Capitol on Jan. 6, forcing lawmakers to lock down in close quarters. Some lawmakers have criticized colleagues for refusing to wear masks while in lockdown.

Jan 20, 2021 - Politics & Policy

Scoop: Joe Biden's COVID-19 bubble

Photo illustration: Aïda Amer/Axios. Photo: Joe Raedle/Getty Images

The incoming administration is planning extraordinary steps to protect its most prized commodity, Joe Biden, including requiring daily employee COVID tests and N95 masks at all times, according to new guidance sent to some incoming employees Tuesday.

Why it matters: The president-elect is 78 years old and therefore a high risk for the virus and its worst effects, despite having received the vaccine. While President Trump's team was nonchalant about COVID protocols — leading to several super-spreader episodes — the new rules will apply to all White House aides in "high proximity to principals."

Jan 19, 2021 - Health

U.S. surpasses 400,000 coronavirus deaths on Trump's final full day in office

Expand chart
Data: CSSE Johns Hopkins University; Chart: Andrew Witherspoon/Axios

Over 400,000 people have died from the coronavirus in the U.S. as of Tuesday, per Johns Hopkins data.

Why it matters: It only took a little over a month for the U.S. to reach this mass casualty after 300,000 COVID deaths were reported last month. That's over 100,000 fatalities in 36 days.