At least 1 in 3 people infected with COVID-19 never develop symptoms, according to new analysis Findings suggest COVID-19 testing should be expanded to those without symptoms who may be unknowingly spreading the virus.
January 22, 2021
LA JOLLA, CA A new data analysis including more than 1.8 million people confirms that asymptomatic infections of the SARS-CoV-2 virus are a major portion of COVID-19's global footprint, representing at least a third of cases.
The findings, published today in Annals of Internal Medicine, build on the authors' prior review of more limited data sets in June 2020, which also found that a significant proportion of SARS-CoV-2 infections did not produce symptoms.
In the new report, Scripps Research's Eric Topol, MD, and Daniel Oran once again dig into the data, this time reviewing a much larger set of 61 studies and reports from around the world including two massive serosurveys in England and Spain that tested the presence of SARS-CoV-2 antibodies in hundreds of thousands of people. In both of those studies, about one-third of the individuals were shown to have had the virus but never experienced symptoms.
The biggest implication of this is that we need to test far more widely and frequently, and not confined to people with symptoms, says Topol, founder and director of the Scripps Research Translational Institute and professor of Molecular Medicine at Scripps Research. We need to urgently get rapid home antigen tests to every household for daily use.
Inexpensive, at-home testing would also help identify those who are presymptomatic, which means they have not yet developed symptoms. About half of all new infections are believed to be caused by people who are either presymptomatic or asymptomatic.
Another implication of our review is that we need to figure out how effective vaccines are in preventing asymptomatic infection, says Oran, a member of the digital medicine group at Scripps Research Translational Institute. Early data are encouraging, but we still have a lot more to learn.
The authors note that it was just about one year ago on January 24, 2020 that the first asymptomatic case of COVID-19 was documented, but largely ignored.
Now we know with certainty that asymptomatic infection is a notable feature of SARS-CoV-2 , Topol says. It's time that we translate this knowledge into smarter testing practices that will help to bring COVID-19 under control.
Video: Eric Topol and Danny Oran discuss asymptomatic COVID-19
COVID-19 Translational Medicine Topol, Eric
Most recent headlines
24/12/2025
What is AI good for? Posted by MTI Film on December 24, 2025
What is AI good for?
What is AI good for?
It's been three years since ChatGPT first cap...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
24/12/2025
Back to All News
Love, Fights, and Everything in Between: Badly in Love' Returns for Season 2
Entertainment
24 December 2025
GlobalJapan
Link copied t...
24/12/2025
Scripps Research study links sleep variability with sleep apnea and hypertension How consumers' digital activity trackers could enable personalized health s...
23/12/2025
How guilas Cibae as Dominican Winter League Games Are Locally Produced for Glob...
23/12/2025
BitFire's Jim Akimchuk on Supplying Scalability and Customization in the Clo...
23/12/2025
CAMB.AI Enables European Athletics to Offer Multi-Language SupportPlan is to eventually offer translation into all languages spoken in EuropeBy Ken Kerschbaumer...
23/12/2025
Analysis: As sports media values trend negative, scarcity and quality are king By Callum McCarthy, Editor-at-Large
Monday, December 22, 2025 - 14:08
Print ...
23/12/2025
ESPN, Disney, and NBA Return to the Animated Altcast Fray With Second Edition of...
23/12/2025
End the Year on a High Note and Donate to the Sports Broadcasting Fund Today! By Ken Kerschbaumer, Editorial Director
Tuesday, December 23, 2025 - 12:25 pm
...
23/12/2025
The year is winding down, the weather outside is frightful, and it's the perfect time to escape into a story that warms the heart. For listeners looking for...
23/12/2025
A Zeus motor is hot fire tested at L3Harris' Camden, Arkansas, solid rocket ...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Lightware will exhibit several major product innovations at ISE 2026, including the new USB-C BOOSTER-V1, Google Meet. integration for various Taurus UCX models...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
23/12/2025
Taking the Stage at Carnegie Hall-On a Global Scale Boston Conservatory Orchestra students reflect on their epic concert marking the 80th session of the UN Gene...
23/12/2025
Back to All News
Netflix's The Great Flood and Culinary Class Wars 2 Top Gl...
23/12/2025
Back to All News
Stranger Things By the Numbers: How the Global Phenomenon Shap...
23/12/2025
Experience the power of WO Automation for Radio's newest service, the System Effectiveness Review. Designed to help you achieve more, a System Effectiveness...
23/12/2025
23 Dec 2025
VEON's Beeline Kazakhstan and Rakuten Symphony Collaborate to A...
23/12/2025
Back to All News
How Steamy Can It Get? Single's Inferno' Season 5 Pre...
23/12/2025
Back to All News
33 Million Global Viewers on Netflix Watched Jake Paul vs. Ant...
23/12/2025
New technique lights up where drugs go in the body, cell by cell Scripps Research scientists developed a technique that maps drug binding in individual cells th...
22/12/2025
SVG New Sponsor Spotlight: Presidio's Neerav Shah on the Role of Its Captiva...
22/12/2025
Hitting the bullseye: Sky Sports readies itself for the biggest PDC World Darts ...
22/12/2025
Unique skillset: Bringing new directors to the world of darts at The Worlds with...
22/12/2025
Gravity Media prepares for a flight of fancy with the PDC World Darts Championsh...
22/12/2025
One hundred and eighty: Gravity Media on hitting the production bullseye at the ...
22/12/2025
The Famous Group's Jon Slusser on Fascinating Fans Through Immersive Content...
22/12/2025
ESPN's Meg Aronowitz on Continuing High-Quality Broadcasts of Collegiate Spo...
22/12/2025
ESPN Takes Data-Driven Storytelling to New Heights with MNF Playbook with Next ...
22/12/2025
For a decade, popular German podcast Fest & Flauschig has hosted an annual Chris...
22/12/2025
Paramount Scores Largest Share Increase Among Distributors as Paramount and CBS...
22/12/2025
New multi-year deal integrates Roku's data to fuel Nielsen's measurement suite
Roku gains access to Nielsen's streaming ratings, showing The Roku C...
22/12/2025
Share Share by:
Copy link
Facebook
X
Whatsapp
Pinterest
Flipboard...
22/12/2025
Berklee Wrapped 2025: Our Top News and Stories A look back at a year highlighted by faculty milestones, major film and television projects, Bob Dylan's ho...
22/12/2025
The works of Plato state that when humans have an experience, some level of change occurs in their brain, which is powered by memory - specifically long-term me...
22/12/2025
Partnership integrates complementary satellite data and AI analytics to enhance security, infrastructure, and environmental monitoring solutions for global cust...
22/12/2025
Workflows allow you to create a sequence of planned events which may be added to your template(s) or inserted directly into your sequential or background playli...
At least 1 in 3 people infected with COVID-19 never develop symptoms, according to new analysis Findings suggest COVID-19 testing should be expanded to those without symptoms who may be unknowingly spreading the virus.
