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What is the best mask for COVID-19? A mechanical engineer explains the science after 2 years of testing masks in his lab

The CDC’s updated mask guidelines say that cloth masks offer the least protection from COVID-19. Differences in the materials masks are made from and the ways they fit are the reason.

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Not all masks offer the same level of protection for you and those around you. Martin Barth/EyeEm via Getty Images

The Centers for Disease Control and Prevention has changed its guidelines about masks and respirators a number of times over the past two years and gave its most recent update on Jan. 14, 2022. The update states that cloth face coverings offer the least protection from the coronavirus compared with surgical masks or N95-style masks. Christian L'Orange is a mechanical engineer who has been testing the performance of masks for the state of Colorado since the beginning of the pandemic. He explains the new CDC guidelines and the science of what makes for a good mask.

1. What changed in the CDC guidelines?

The CDC currently recommends that you “wear the most protective mask you can that fits well and that you will wear consistently.” The question, then, is what type of mask offers the best protection for you – by filtering the air you breathe in – and for those around you – by filtering the air you breathe out?

The CDC’s updated guidelines clearly lay out the hierarchy of protection: “Loosely woven cloth products provide the least protection, layered finely woven products offer more protection, well-fitting disposable surgical masks and KN95s offer even more protection, and well-fitting NIOSH-approved respirators (including N95s) offer the highest level of protection.”

From a performance standpoint, the N95 and KN95 masks are the best option. While supply chain limitations led to the CDC recommending people not wear N95s early in the pandemic, today they are easily obtainable and should be your first choice if you want the most protection.

The biggest change in the new guidelines has to do with cloth masks. Previous guidance from the CDC had said that some cloth masks could offer acceptable levels of protection. The new guidance still acknowledges that cloth masks can offer a small amount of protection but places them at the very bottom of the bunch.

A tangled mass of fibers, as seen through a microscope.
N95 masks are made from a tangled web of tiny plastic fibers that are very effective at trapping particles. Alexander Klepnev via Wikimedia Commons, CC BY-SA

2. What’s the difference between N95, surgical and cloth mask materials?

The effectiveness of a mask – how much protection a mask provides the wearer – is a combination of two major elements. First, there’s the ability of the material to capture particles. The second factor is the fraction of inhaled or exhaled air leaking out from around the mask – essentially, how well a mask fits.

Most mask materials can be thought of as a tangled net of small fibers. Particles passing through a mask are stopped when they physically touch one of those fibers. N95s, KN95s and surgical masks are purpose-built to be effective at removing particles from air. Their fibers are typically made from melt-blown plastics, often polypropylene, and the strands are tiny – often less than four thousandths of an inch (10 micrometers) in diameter – or approximately one third the width of a human hair. These small fibers create a large amount of surface area within the mask for filtering and collecting particles. Although the specific construction and thickness of the materials used in N95, KN95 and surgical masks can vary, the filter media used are often quite similar.

These fibers are very tightly packed together so the gaps a particle must navigate through are very small. This results in a high probability that particles will end up touching and sticking to a fiber as they pass through a mask. These polypropylene materials also often have a static charge that can help attract and catch particles.

Cloth masks are typically made of common woven materials such as cotton or polyester. The fibers are often large and less densely packed together, meaning particles can easily pass through the material. Adding more layers can help, but stacking layers has a diminishing return and the performance of a cloth mask, even with multiple layers, will still typically not match that of surgical mask or N95.

A side view of man wearing a surgical mask
Surgical masks are made of good materials but are hard to seal against the face and often allow air to escape past a person’s cheeks. Krisanapong Detraphiphat/Moment via Getty Images

3. How much does fit matter for masks?

Fit is the other major component in how effective a mask is. Even if the materials used in a mask were perfect and it removed all particles from the air that passed through it, a mask can offer protection only if it doesn’t leak.

When you breathe in and out, air will always take the path of least resistance. If there are any gaps between a mask and someone’s face, a substantial fraction of every breath will seep out through those gaps and the mask will provide relatively little protection.

Many cloth mask designs simply do not seal well. They are not stiff enough to push against the face, there are gaps where the mask doesn’t even come in contact with the face and it is not possible to cinch them tightly enough against the skin to form a decent seal.

But leaking is a concern for all masks. Although the materials used in surgical masks are quite effective, they often bunch and fold on the sides. These gaps provide an easy route for air and particles to leak out. Knotting and tucking surgical masks or wearing a cloth mask over a surgical mask can both significantly reduce leakage.

N95 masks aren’t immune to this problem either; if the nose clip isn’t securely pushed against your face, the mask is leaking. What makes N95s unique is that a specific requirement of the N95 certification process is making sure the masks can form a good seal.

4. What is different about omicron?

The mechanics of how masks function is likely no different for omicron than any other variant. The difference is that the omicron variant is more easily transmitted than previous variants. This high level of infectiousness makes wearing good-quality masks and wearing them correctly to limit the chances of catching or spreading the coronavirus that much more critical.

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Unfortunately, the attributes that make for a good mask are the very things that make masks uncomfortable and not very stylish. If your cloth mask is comfy and light and feels like you are wearing nothing at all, it probably isn’t doing much to keep you and others safe from the coronavirus. The protection offered by a high-quality, well-fitting N95 or KN95 is the best. Surgical masks can be very effective at filtering out particles, but getting them to fit correctly can be tricky and makes the overall protection they will provide you questionable. If you have other options, cloth masks should be a last choice.

Christian L'Orange receives funding associated with the testing and evaluation of testing masks including fee-for-service testing and funding from the World Health Organization.

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Analyst reviews Apple stock price target amid challenges

Here’s what could happen to Apple shares next.

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They said it was bound to happen.

It was Jan. 11, 2024 when software giant Microsoft  (MSFT)  briefly passed Apple  (AAPL)  as the most valuable company in the world.

Microsoft's stock closed 0.5% higher, giving it a market valuation of $2.859 trillion. 

It rose as much as 2% during the session and the company was briefly worth $2.903 trillion. Apple closed 0.3% lower, giving the company a market capitalization of $2.886 trillion. 

"It was inevitable that Microsoft would overtake Apple since Microsoft is growing faster and has more to benefit from the generative AI revolution," D.A. Davidson analyst Gil Luria said at the time, according to Reuters.

The two tech titans have jostled for top spot over the years and Microsoft was ahead at last check, with a market cap of $3.085 trillion, compared with Apple's value of $2.684 trillion.

Analysts noted that Apple had been dealing with weakening demand, including for the iPhone, the company’s main source of revenue. 

Demand in China, a major market, has slumped as the country's economy makes a slow recovery from the pandemic and competition from Huawei.

Sales in China of Apple's iPhone fell by 24% in the first six weeks of 2024 compared with a year earlier, according to research firm Counterpoint, as the company contended with stiff competition from a resurgent Huawei "while getting squeezed in the middle on aggressive pricing from the likes of OPPO, vivo and Xiaomi," said senior Analyst Mengmeng Zhang.

“Although the iPhone 15 is a great device, it has no significant upgrades from the previous version, so consumers feel fine holding on to the older-generation iPhones for now," he said.

A man scrolling through Netflix on an Apple iPad Pro. Photo by Phil Barker/Future Publishing via Getty Images.

Future Publishing/Getty Images

Big plans for China

Counterpoint said that the first six weeks of 2023 saw abnormally high numbers with significant unit sales being deferred from December 2022 due to production issues.

Apple is planning to open its eighth store in Shanghai – and its 47th across China – on March 21.

Related: Tech News Now: OpenAI says Musk contract 'never existed', Xiaomi's EV, and more

The company also plans to expand its research centre in Shanghai to support all of its product lines and open a new lab in southern tech hub Shenzhen later this year, according to the South China Morning Post.

Meanwhile, over in Europe, Apple announced changes to comply with the European Union's Digital Markets Act (DMA), which went into effect last week, Reuters reported on March 12.

Beginning this spring, software developers operating in Europe will be able to distribute apps to EU customers directly from their own websites instead of through the App Store.

"To reflect the DMA’s changes, users in the EU can install apps from alternative app marketplaces in iOS 17.4 and later," Apple said on its website, referring to the software platform that runs iPhones and iPads. 

"Users will be able to download an alternative marketplace app from the marketplace developer’s website," the company said.

Apple has also said it will appeal a $2 billion EU antitrust fine for thwarting competition from Spotify  (SPOT)  and other music streaming rivals via restrictions on the App Store.

The company's shares have suffered amid all this upheaval, but some analysts still see good things in Apple's future.

Bank of America Securities confirmed its positive stance on Apple, maintaining a buy rating with a steady price target of $225, according to Investing.com

The firm's analysis highlighted Apple's pricing strategy evolution since the introduction of the first iPhone in 2007, with initial prices set at $499 for the 4GB model and $599 for the 8GB model.

BofA said that Apple has consistently launched new iPhone models, including the Pro/Pro Max versions, to target the premium market. 

Analyst says Apple selloff 'overdone'

Concurrently, prices for previous models are typically reduced by about $100 with each new release. 

This strategy, coupled with installment plans from Apple and carriers, has contributed to the iPhone's installed base reaching a record 1.2 billion in 2023, the firm said.

More Tech Stocks:

Apple has effectively shifted its sales mix toward higher-value units despite experiencing slower unit sales, BofA said.

This trend is expected to persist and could help mitigate potential unit sales weaknesses, particularly in China. 

BofA also noted Apple's dominance in the high-end market, maintaining a market share of over 90% in the $1,000 and above price band for the past three years.

The firm also cited the anticipation of a multi-year iPhone cycle propelled by next-generation AI technology, robust services growth, and the potential for margin expansion.

On Monday, Evercore ISI analysts said they believed that the sell-off in the iPhone maker’s shares may be “overdone.”

The firm said that investors' growing preference for AI-focused stocks like Nvidia  (NVDA)  has led to a reallocation of funds away from Apple. 

In addition, Evercore said concerns over weakening demand in China, where Apple may be losing market share in the smartphone segment, have affected investor sentiment.

And then ongoing regulatory issues continue to have an impact on investor confidence in the world's second-biggest company.

“We think the sell-off is rather overdone, while we suspect there is strong valuation support at current levels to down 10%, there are three distinct drivers that could unlock upside on the stock from here – a) Cap allocation, b) AI inferencing, and c) Risk-off/defensive shift," the firm said in a research note.

Related: Veteran fund manager picks favorite stocks for 2024

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Major typhoid fever surveillance study in sub-Saharan Africa indicates need for the introduction of typhoid conjugate vaccines in endemic countries

There is a high burden of typhoid fever in sub-Saharan African countries, according to a new study published today in The Lancet Global Health. This high…

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There is a high burden of typhoid fever in sub-Saharan African countries, according to a new study published today in The Lancet Global Health. This high burden combined with the threat of typhoid strains resistant to antibiotic treatment calls for stronger prevention strategies, including the use and implementation of typhoid conjugate vaccines (TCVs) in endemic settings along with improvements in access to safe water, sanitation, and hygiene.

Credit: IVI

There is a high burden of typhoid fever in sub-Saharan African countries, according to a new study published today in The Lancet Global Health. This high burden combined with the threat of typhoid strains resistant to antibiotic treatment calls for stronger prevention strategies, including the use and implementation of typhoid conjugate vaccines (TCVs) in endemic settings along with improvements in access to safe water, sanitation, and hygiene.

 

The findings from this 4-year study, the Severe Typhoid in Africa (SETA) program, offers new typhoid fever burden estimates from six countries: Burkina Faso, Democratic Republic of the Congo (DRC), Ethiopia, Ghana, Madagascar, and Nigeria, with four countries recording more than 100 cases for every 100,000 person-years of observation, which is considered a high burden. The highest incidence of typhoid was found in DRC with 315 cases per 100,000 people while children between 2-14 years of age were shown to be at highest risk across all 25 study sites.

 

There are an estimated 12.5 to 16.3 million cases of typhoid every year with 140,000 deaths. However, with generic symptoms such as fever, fatigue, and abdominal pain, and the need for blood culture sampling to make a definitive diagnosis, it is difficult for governments to capture the true burden of typhoid in their countries.

 

“Our goal through SETA was to address these gaps in typhoid disease burden data,” said lead author Dr. Florian Marks, Deputy Director General of the International Vaccine Institute (IVI). “Our estimates indicate that introduction of TCV in endemic settings would go to lengths in protecting communities, especially school-aged children, against this potentially deadly—but preventable—disease.”

 

In addition to disease incidence, this study also showed that the emergence of antimicrobial resistance (AMR) in Salmonella Typhi, the bacteria that causes typhoid fever, has led to more reliance beyond the traditional first line of antibiotic treatment. If left untreated, severe cases of the disease can lead to intestinal perforation and even death. This suggests that prevention through vaccination may play a critical role in not only protecting against typhoid fever but reducing the spread of drug-resistant strains of the bacteria.

 

There are two TCVs prequalified by the World Health Organization (WHO) and available through Gavi, the Vaccine Alliance. In February 2024, IVI and SK bioscience announced that a third TCV, SKYTyphoid™, also achieved WHO PQ, paving the way for public procurement and increasing the global supply.

 

Alongside the SETA disease burden study, IVI has been working with colleagues in three African countries to show the real-world impact of TCV vaccination. These studies include a cluster-randomized trial in Agogo, Ghana and two effectiveness studies following mass vaccination in Kisantu, DRC and Imerintsiatosika, Madagascar.

 

Dr. Birkneh Tilahun Tadesse, Associate Director General at IVI and Head of the Real-World Evidence Department, explains, “Through these vaccine effectiveness studies, we aim to show the full public health value of TCV in settings that are directly impacted by a high burden of typhoid fever.” He adds, “Our final objective of course is to eliminate typhoid or to at least reduce the burden to low incidence levels, and that’s what we are attempting in Fiji with an island-wide vaccination campaign.”

 

As more countries in typhoid endemic countries, namely in sub-Saharan Africa and South Asia, consider TCV in national immunization programs, these data will help inform evidence-based policy decisions around typhoid prevention and control.

 

###

 

About the International Vaccine Institute (IVI)
The International Vaccine Institute (IVI) is a non-profit international organization established in 1997 at the initiative of the United Nations Development Programme with a mission to discover, develop, and deliver safe, effective, and affordable vaccines for global health.

IVI’s current portfolio includes vaccines at all stages of pre-clinical and clinical development for infectious diseases that disproportionately affect low- and middle-income countries, such as cholera, typhoid, chikungunya, shigella, salmonella, schistosomiasis, hepatitis E, HPV, COVID-19, and more. IVI developed the world’s first low-cost oral cholera vaccine, pre-qualified by the World Health Organization (WHO) and developed a new-generation typhoid conjugate vaccine that is recently pre-qualified by WHO.

IVI is headquartered in Seoul, Republic of Korea with a Europe Regional Office in Sweden, a Country Office in Austria, and Collaborating Centers in Ghana, Ethiopia, and Madagascar. 39 countries and the WHO are members of IVI, and the governments of the Republic of Korea, Sweden, India, Finland, and Thailand provide state funding. For more information, please visit https://www.ivi.int.

 

CONTACT

Aerie Em, Global Communications & Advocacy Manager
+82 2 881 1386 | aerie.em@ivi.int


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US Spent More Than Double What It Collected In February, As 2024 Deficit Is Second Highest Ever… And Debt Explodes

US Spent More Than Double What It Collected In February, As 2024 Deficit Is Second Highest Ever… And Debt Explodes

Earlier today, CNBC’s…

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US Spent More Than Double What It Collected In February, As 2024 Deficit Is Second Highest Ever... And Debt Explodes

Earlier today, CNBC's Brian Sullivan took a horse dose of Red Pills when, about six months after our readers, he learned that the US is issuing $1 trillion in debt every 100 days, which prompted him to rage tweet, (or rageX, not sure what the proper term is here) the following:

We’ve added 60% to national debt since 2018. Germany - a country with major economic woes - added ‘just’ 32%.   

Maybe it will never matter.   Maybe MMT is real.   Maybe we just cancel or inflate it out. Maybe career real estate borrowers or career politicians aren’t the answer.

I have no idea.  Only time will tell.   But it’s going to be fascinating to watch it play out.

He is right: it will be fascinating, and the latest budget deficit data simply confirmed that the day of reckoning will come very soon, certainly sooner than the two years that One River's Eric Peters predicted this weekend for the coming "US debt sustainability crisis."

According to the US Treasury, in February, the US collected $271 billion in various tax receipts, and spent $567 billion, more than double what it collected.

The two charts below show the divergence in US tax receipts which have flatlined (on a trailing 6M basis) since the covid pandemic in 2020 (with occasional stimmy-driven surges)...

... and spending which is about 50% higher compared to where it was in 2020.

The end result is that in February, the budget deficit rose to $296.3 billion, up 12.9% from a year prior, and the second highest February deficit on record.

And the punchline: on a cumulative basis, the budget deficit in fiscal 2024 which began on October 1, 2023 is now $828 billion, the second largest cumulative deficit through February on record, surpassed only by the peak covid year of 2021.

But wait there's more: because in a world where the US is spending more than twice what it is collecting, the endgame is clear: debt collapse, and while it won't be tomorrow, or the week after, it is coming... and it's also why the US is now selling $1 trillion in debt every 100 days just to keep operating (and absorbing all those millions of illegal immigrants who will keep voting democrat to preserve the socialist system of the US, so beloved by the Soros clan).

And it gets even worse, because we are now in the ponzi finance stage of the Minsky cycle, with total interest on the debt annualizing well above $1 trillion, and rising every day

... having already surpassed total US defense spending and soon to surpass total health spending and, finally all social security spending, the largest spending category of all, which means that US debt will now rise exponentially higher until the inevitable moment when the US dollar loses its reserve status and it all comes crashing down.

We conclude with another observation by CNBC's Brian Sullivan, who quotes an email by a DC strategist...

.. which lays out the proposed Biden budget as follows:

The budget deficit will growth another $16 TRILLION over next 10 years. Thats *with* the proposed massive tax hikes.

Without them the deficit will grow $19 trillion.

That's why you will hear the "deficit is being reduced by $3 trillion" over the decade.

No family budget or business could exist with this kind of math.

Of course, in the long run, neither can the US... and since neither party will ever cut the spending which everyone by now is so addicted to, the best anyone can do is start planning for the endgame.

Tyler Durden Tue, 03/12/2024 - 18:40

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