Effectiveness of wearing masks to stop spread of COVID-19

Dr. Travis Riddell wants to reiterate how important it is to wear face masks.

The Teton District health officer has updated his recommendation on mask wearing, replacing an earlier version with one that further outlines current research. The current recommendation updates the situations in which people should wear masks, or “face coverings.”

“It’s fantastic to see things coming back to life in town,” Riddell said at the May 29 community update. “Of course, that does come with some risk, and I think that’s where we have to continue to be vigilant.”

Many of the times to wear a mask will be familiar. Riddell recommends that people wear them in grocery stores, at the doctor’s office and in other public situations in which social distancing cannot be maintained.

His recommendation also says businesses should encourage customers and employees to wear them when interacting. People are asked to wear masks if they use public transportation.

Riddell clarifies situations in which people do not need to wear masks. Folks who have returned to work don’t need to wear them when they are alone in their offices, and people don’t need to mask up when they are interacting with people in their immediate family, when they are driving alone in their personal cars or when they are seated at a restaurant with proper social distancing.

Part of Riddell’s hope in revising the recommendation is to share more information on the efficacy of masks. Arguments against wearing cloth face coverings often hinge on the fact that such masks can’t stop all viral particles because the weave of the cloth is too large.

While that is true, cloth face coverings that shield both the nose and mouth have been shown to diminish the number of viral particles infected people exhale. Recent studies show that cloth masks have a total filtration effect of about 50% to 70%. That reduction in airborne viral particles lowers the amount of viral shedding when an infected person breathes, coughs or sneezes, thereby reducing the potential for them to spread the virus.

St. John’s Health CEO Dr. Paul Beaupre also talked about masks at the last community update, saying asymptomatic carriers of COVID-19 could exhale 200 million viral particles should they sneeze because of an allergy.

“So if you’re standing in front of that person for the time that they sneeze, you probably will get COVID,” he said. “So this is one of the reasons why we believe so strongly in masking: Masking prevents the transmission of most of those particles.”

Research Riddell cites in the recommendation from Italy and China found that somewhere between 50% and 80% of carriers are asymptomatic. That means those people could inadvertently spread the disease if they don’t wear masks.

Wearing masks, Riddell has argued, is important to maintain the progress the community has made against the virus. The community COVID dashboard reports that the last lab-confirmed case of COVID-19 in Teton County was May 16. That means Teton County has gone 23 days with no reports of new positives. The dashboard also reported zero active cases Monday.

For much of the pandemic, Teton County was one of the hardest-hit counties in Wyoming. But the dearth of cases over the past few weeks means places like Natrona County, which reported five new cases Monday, have moved ahead in total lab-confirmed positives.

The Wyoming Department of Health, in its daily coronavirus update, reported a total of 14 new cases Monday in Campbell, Fremont, Hot Springs, Natrona, Sweetwater and Uinta counties.

Though Teton County has effectively flattened its curve, Beaupre warned that the virus hasn’t magically disappeared. Tourism numbers are rising and because other communities are still seeing active cases, it is almost inevitable COVID-19 will pop up in Teton County again.

“This virus is still very much present among us,” Beaupre said. “And it will be present among us until we have a mass-produced vaccine.”

Contact Tom Hallberg at 732-7079 or thallberg@jhnewsandguide.com.

Tom Hallberg covers a little bit of everything, from skiing to long-form feature stories. A Teton Valley, Idaho, transplant by way of Portland and Bend, Oregon, he spends his time outside work writing fiction, splitboarding and climbing.

(15) comments

Jim Olson

Here, I did the work for you. From Wikipedia:

"Abusive ad hominem

See also: Name calling and Verbal abuse

Abusive Ad hominem lies near the bottom end of Graham's Hierarchy of Disagreement

Abusive ad hominem argument (or direct ad hominem) is associated with an attack to the character of the person carrying an argument. This kind of argument, besides usually being fallacious, is also counterproductive, as a proper dialogue is hard to achieve after such an attack."

Jim Olson

Terrance, do a search for the meaning of "Ad Hominem" And then look in the mirror.

Jim Olson


Thanks for your "zero substance" reply. Do you have any factual information to share or do you think that your argument has merit by merely smearing Kennedy? Calling him names? Is that all you got? Don't debate me on facts, because I will completely dismantle you!


You've got a gun with no ammo. He like the rest of the clan, is a rich kid living in an ivory tower and inventing positions that his money can buy him. Show me his resume. Works(?) at non-profits supported by the other dilatants. Saw once was a ADA, what was his conviction record? Like his idle, John F Kerry you are looking at zeros. No show job. Since he was fired nothing. Lots of spare time. Yes we are dealing with inbred bunch of numb nuts. But you are wasting your time quoting this Maynard G. Crebs..

Jim Olson

One more point, Kirk. Your post has no real substance. You use quotation marks to denote someone else's opinion. Who might that be. You've got to do better than merely copying and pasting a general statement with no actual substance. You, or your source claims that CHD is guilty of putting out "anti-vaccine propaganda". OK, tell us all just what that propaganda is. Saying so doesn't make it so. Come up with a few facts to bolster your empty claims. Don't just resort to your own Ad Hominem attacks....

Jim Olson


Yes, Children's Health Defense is vilified by the corporate owned press. Big Pharma has many billions at stake. All four Big Pharma companies are convicted felons. In 1989 during the Reagan administration a law was passed to give vaccine manufacturers total immunity from lawsuits. (I found this out from the CHD website). So they are highly motivated to get anything on the market as quickly as possible with the minimum amount of testing. CHD is not, and I repeat is not anti vaccine. They are pro "safe" vaccine. The head of CHD allowed his own children to be vaccinated. The propaganda put out by the mainstream press, in cahoots with big Pharma tries to vilify CHD with Ad Hominem attacks with no substance. The leader of CHD (Robert F. Kennedy Jr.) has offered to debate anyone from Big Pharma anytime, but has been turned down repeatedly because they know he is right and will roast them in any debate.

So Kirk, I recommend that you expand the list of sources you use to include ones that don't have financial axes to grind.

Generally, who would you think is less biased, Big Pharma with billions of dollars on the line, or a courageous individual who is challenged financially just to get an opposing viewpoint out there with no profit motive? I'll take Kennedy and CHD any day over the convicted felons of Big Pharma!


If this is the Robert F. Kennedy Jr. that I'm thinking about, then you don't have the credible source. He has a lot of time on his hands, as others work for a living and can't be bothered with him or his nonsense. He does have that Kennedy desire to get after the chicks however. Think he's on the 4th of fifth wife by now.

sean henry


the facts don't support this..please stay out of my life doc.

Gary Givens

The WHO just came out with the following: “Coronavirus spread by people with no symptoms 'appears to be rare,” WHO official says. So much conflicting information out there by our Medical Specialists - who to believe? Our local health advisors or the World Health Organization? You decide.

Kirk Speckhals

Maybe research the source before reading their article.

"Children's Health Defense is an American 501c3 nonprofit advocacy organization, known for its anti-vaccine activism. Much of the material put forth by the organization involves manipulation of information and anti-vaccine propaganda."


Another way to look at is, wearing a mask is like wearing a seatbelt. It's not 100% effective but it beats not wearing one if you are in a wreck. You can't always control a wreck. I saw the other comment about Kennedy and I'd have to agree with you. The guy's a nut job.

Jim Olson

I've got to say that this article reeks slightly of propaganda. There has been a lot of propaganda regarding the virus. This story only vaguely references any sources of it's assertions.

There is a completely different story to be told. For a different opinion please reference this article: https://childrenshealthdefense.org/news/lockdown-lunacy-the-thinking-persons-guide/?utm_source=salsa&eType=EmailBlastContent&eId=fb4def25-9094-4036-b0bc-affc7582badc

The article lists 17 "facts" that are contradictory to the current media narrative.

It is very extensive with many references from doctors and organizations.

To whet your appetite: "On May 29th the World Health Organization announced that masks should only be worn by healthy people if they are taking care of someone infected with CV-19"

Or: “If you do not have any respiratory symptoms such as fever, cough or runny nose, you do not need to wear a mask,” Dr. April Baller, a public health specialist for the WHO, says in a video on the world health body’s website posted in March. “Masks should only be used by healthcare workers, caretakers or by people who are sick with symptoms of fever and cough.”

This is just one tiny part of the scathing article which cites numerous studies to support it's claims. I hope everyone reading this will go read this very extensive rebuke to the current narrative.

Nevertheless, the authorities will run with their narrative and take away even more of our rights while enriching the wealthy (434 billion dollars to American billionaires in two months), and gutting the economy. The "lockdown" should have never, ever happened!

Tom Henry

The majority of tourists and visitors are not wearing facial protection, oblivious to their role in protecting others. Town council should immediately enact an emergency order requiring everyone to wear masks in public spaces.

Mark Witherman

The thing is, the CDC now says CV is less deadly than the flu at .26% of those infected. So why do anything different? https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scenarios.html


If you see their web site sponsored by John Hopkins that rate is higher. They show a mortality rate map. The rate in Wyoming is about 1.5%. We are at about the national average. Some areas show larger numbers. Now many of the sickest states are coming to Jackson, hence the purpose of this article.

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