London Daily

Focus on the big picture.
Wednesday, Jul 30, 2025

With omicron, you need a mask that means business

With omicron, you need a mask that means business

To block a variant this transmissible, scientists say you need an N95 or other high-filtration mask. Here's how to find a good one and when to wear it.

With another coronavirus variant racing across the U.S., once again health authorities are urging people to mask up indoors. Yes, you've heard it all before. But given how contagious omicron is, experts say, it's seriously time to upgrade to an N95 or similar high-filtration respirator when you're in public indoor spaces.

"Cloth masks are not going to cut it with omicron," says Linsey Marr, a researcher at Virginia Tech who studies how viruses transmit in the air.

Omicron is so much more transmissible than coronavirus variants that have come before it. It spreads at least three times faster than delta. One person is infecting at least three others at a time on average, based on data from other countries.

"It's very contagious," says Dr. Robert Wachter, chair of the Department of Medicine at the University of California, San Francisco. "And the kind of encounter that you could have had with prior versions of the virus that would have left you uninfected, there's now a good chance you will get infected from it."

True, a cloth mask can be a "marginally OK to maybe a decent filter," Marr says. But with something as highly transmissible as omicron, just "OK" isn't good enough.

Marr notes that preliminary data from scientists at the University of Hong Kong has shown that omicron multiplies 70 times faster inside human respiratory tract tissue than the delta variant does. That study also found that omicron reaches higher levels in respiratory tract tissue 48 hours after infection, compared with delta.

"That would suggest to me that maybe it reaches higher levels and then we spew out more [virus particles] if we're infected," Marr says. And while it's too soon to tell, she says it's conceivable that omicron is so good at infecting us, we just need to breathe in fewer viral particles of omicron to get infected.

And virus particles from an infectious person can linger in the air indoors for minutes or even hours after they leave a room in some situations, says Dr. Abraar Karan, an infectious disease physician at Stanford University. "I think that people need to realize that transmission here can happen even when you're not near somebody," he says.

Why high-filtration respirators are better and how to find a legitimate one


Given all this, you want a mask that means business when it comes to blocking viral particles. Unlike cloth masks, N95, KN95 and KF94 respirators are all made out of material with an electrostatic charge, which "actually pulls these particles in as they're floating around and prevents you from inhaling those particles," Karan notes. "And that really is key" — because if you don't inhale virus particles, they can't multiply in your respiratory tract.

The material in surgical masks also has an electrostatic charge. But surgical masks tend to fit loosely, and a snug fit — with no gaps around nose, cheeks or chin — "really makes a big difference," says Marr, who has studied mask efficacy.

KN95s tend to be a bit more comfortable than N95s, but counterfeits continue to be a problem. For safer shopping, check out a site like Project N95, a nonprofit that helps consumers find legitimate personal protective equipment. Or check the CDC's site for advice on how to spot a counterfeit and a list of NIOSH-approved N95s. (For health care workers who need surgical N95s, here's the CDC's list of trusted sources.)

For maximum protection, make sure your N95 fits snugly as well, creating a seal around your mouth and nose. The CDC explains what makes a good fit and how to test that yours is sealing well.

Still, surgical masks are cheaper than respirators. And if cost is a factor for you, at a minimum consider topping a surgical mask with a cloth mask to ensure a tighter fit, or get a mask fitter — a frame that fits over your surgical mask to make it more snug. While these options won't offer as much protection as an N95, they're a big improvement over a cloth mask alone, Karan and Marr say.

When to mask up


As to when to wear a mask, obviously you want to cover up when you're using public transit, including airports and airplanes, and when you're indoors in grocery stores or other public places, as with previous surges. Check to see whether where you live has a lot of cases — most places do right now.

Wachter says he's also covering up indoors with small groups of friends and family unless everyone is vaccinated and boosted. If they're not boosted, he says, "I consider them to be somewhere between vaccinated and unvaccinated, and I act appropriately if I'm going to be around them." That means he either has everyone mask up, or he has everyone take a rapid test to make sure no one is infectious at that moment. "One or the other." This is especially important if anyone attending is high-risk.

Marr says that with omicron surging, she'd have kids wear respirators if possible when they're indoors in public spaces. Parents searching for good respirator options for their children can check out the work of Aaron Collins, aka "Mask Nerd," a mechanical engineer with a background in aerosol science. He's been testing the filtration efficiencies of hundreds of masks and respirators on the market. You can find his reviews on his YouTube channel. (This spreadsheet on kids' masks may also be helpful.)

Combined with getting vaccinated and boosted, upgrading to a high-filtration mask will be key to enjoying a safer holiday season without having to hibernate, experts say.

"I have a lot of confidence in the vaccines, if you're boosted, in protecting against severe outcomes," Marr says, "and I have a lot of confidence in an N95 and similar types of respirators. And I think that with those two things, you can still go about a lot of your normal activities."

Comments

mike 4 year ago
What a nonsense!

Newsletter

Related Articles

0:00
0:00
Close
Former Judge Charged After Drunk Driving Crash Kills Comedian in Brazil
Jeff Bezos hasn’t paid a dollar in taxes for decades. He makes billions and pays $0 in taxes, LEGALLY
China Increases Use of Exit Bans Amid Rising U.S. Tensions
IMF Upgrades Global Growth Forecast as Weaker Dollar Supports Outlook
Procter & Gamble to Raise U.S. Prices to Offset One‑Billion‑Dollar Tariff Cost
House Republicans Move to Defund OECD Over Global Tax Dispute
Botswana Seeks Controlling Stake in De Beers as Anglo American Prepares Exit
Trump Administration Proposes Repeal of Obama‑Era Endangerment Finding, Dismantling Regulatory Basis for CO₂ Emissions Limits
France Opens Criminal Investigation into X Over Algorithm Manipulation Allegations
A family has been arrested in the UK for displaying the British flag
Mel Gibson refuses to work with Robert De Niro, saying, "Keep that woke clown away from me."
Trump Steamrolls EU in Landmark Trade Win: US–EU Trade Deal Imposes 15% Tariff on European Imports
ChatGPT CEO Sam Altman says people share personal info with ChatGPT but don’t know chats can be used as court evidence in legal cases.
The British propaganda channel BBC News lies again.
Deputy attorney general's second day of meeting with Ghislaine Maxwell has concluded
Controversial March in Switzerland Features Men Dressed in Nazi Uniforms
Politics is a good business: Barack Obama’s Reported Net Worth Growth, 1990–2025
Thai Civilian Death Toll Rises to 12 in Cambodian Cross-Border Attacks
TSUNAMI: Trump Just Crossed the Rubicon—And There’s No Turning Back
Over 120 Criminal Cases Dismissed in Boston Amid Public Defender Shortage
UN's Top Court Declares Environmental Protection a Legal Obligation Under International Law
"Crazy Thing": OpenAI's Sam Altman Warns Of AI Voice Fraud Crisis In Banking
The Podcaster Who Accidentally Revealed He Earns Over $10 Million a Year
Trump Announces $550 Billion Japanese Investment and New Trade Agreements with Indonesia and the Philippines
US Treasury Secretary Calls for Institutional Review of Federal Reserve Amid AI‑Driven Growth Expectations
UK Government Considers Dropping Demand for Apple Encryption Backdoor
Severe Flooding in South Korea Claims Lives Amid Ongoing Rescue Operations
Japanese Man Discovers Family Connection Through DNA Testing After Decades of Separation
Russia Signals Openness to Ukraine Peace Talks Amid Escalating Drone Warfare
Switzerland Implements Ban on Mammography Screening
Japanese Prime Minister Vows to Stay After Coalition Loses Upper House Majority
Pogacar Extends Dominance with Stage Fifteen Triumph at Tour de France
CEO Resigns Amid Controversy Over Relationship with HR Executive
Man Dies After Being Pulled Into MRI Machine Due to Metal Chain in New York Clinic
NVIDIA Achieves $4 Trillion Valuation Amid AI Demand
US Revokes Visas of Brazilian Corrupted Judges Amid Fake Bolsonaro Investigation
U.S. Congress Approves Rescissions Act Cutting Federal Funding for NPR and PBS
North Korea Restricts Foreign Tourist Access to New Seaside Resort
Brazil's Supreme Court Imposes Radical Restrictions on Former President Bolsonaro
Centrist Criticism of von der Leyen Resurfaces as she Survives EU Confidence Vote
Judge Criticizes DOJ Over Secrecy in Dropping Charges Against Gang Leader
Apple Closes $16.5 Billion Tax Dispute With Ireland
Von der Leyen Faces Setback Over €2 Trillion EU Budget Proposal
UK and Germany Collaborate on Global Military Equipment Sales
Trump Plans Over 10% Tariffs on African and Caribbean Nations
Flying Taxi CEO Reclaims Billionaire Status After Stock Surge
Epstein Files Deepen Republican Party Divide
Zuckerberg Faces $8 Billion Privacy Lawsuit From Meta Shareholders
FIFA Pressured to Rethink World Cup Calendar Due to Climate Change
SpaceX Nears $400 Billion Valuation With New Share Sale
×