Tracking Delta breakthroughs -- Part 2 (Mitigation via masks)

 Last update: Friday 8/27/21

This is the second in a series of notes on this blog that briefly summarize what every health conscious U.S. resident should know about the Delta variant. Part 1 discussed Delta's most disruptive properties. This second part focuses on the most visible way that vaccinated persons can help to mitigate the spread of Delta to those who have not been vaccinated yet and to those who need a booster shot to achieve full immunity. 

The CDC's May 2021 guidance declared that vaccinated persons did not have to wear masks or maintain social distancing in most public places. 

• "Vaccinated Americans May Go Without Masks in Most Places, Federal Officials Say", Roni Caryn Rabin, Apoorva Mandavilli and Noah Weiland, NY Times, 5/13/21 ... Note: This article also cites the CDC dropping its distancing requirements

In late July, the CDC reversed its guidance upon learning about (1) the hundreds of breakthrough cases in Provincetown, Massachusetts, and (2) that breakthrough cases carried the same very high loads of Delta virus in their throats and noses as unvaccinated persons who became infected; but its July reversal only declared that vaccinated persons should wear masks in public places where infections were surging ... with no mention of distancing, repeat: no mention of distancing, the most powerful group of mitigation procedures.

• "Interim Public Health Recommendations for Fully Vaccinated People", Centers for Disease Control,. 7/28/21

Question #1 Our best vaccines are highly effective; they reduce severe illness and death by 95 percent. So why do we still need to employ any form of mitigation?

Answer #1: Our vaccines were not designed to prevent infections. Unfortunately, the Delta variant is far more transmissible than previous variants, so much so that vaccinated persons who become infected can easily transmit the virus to others. The vast majority of vaccinated persons who become infected by Delta will experience no symptoms or only mld symptoms, so they may not be aware that they have been infected; they will be silent spreaders. But if these silent breakthroughs infect unvaccinated persons, their unvaccinated victims may experience severe illness or death.]

As of 8/25/21, about 52 percent of the total U.S. population has been fully vaccinated. (Note: Vaccines have not yet been approved for children under 12 years old). This means that 48 percent of the population is still at risk for severe illness or death if they become infected by Delta. 

Unfortunately, a small percentage of fully vaccinated persons have not developed an adequate level of immunity, e.g., persons with cancer, compromised immune systems, and some of the elderly. If they become infected, they will also be at risk for severe illness or death.

Delta has cancelled the possibility that any nation can achieve herd immunity, so there are only two ways to protect the vulnerable members of our communities:

• Persuade them to become fully vaccinated ... including booster shots if required for them to achieve full immunity
  
  
• Reduce their risk of infection by maintaining appropriate mitigation practices.

Question #2: Why didn't the CDC advocate a return to distancing as well as masking? Distancing is far more effective than masking in reducing new infections within a community

Answer #2: There is no rational explanation for the CDC's decision that does not involve political considerations. Although the CDC has loudly proclaimed that its guidance is solely determined by "the science", distancing usually requires some businesses to operate at lower capacity, thereby impeding our economy's full recovery. As consequence, presidents, governors, and mayors will face political backlash if they advocate a return to extensive use of any form of distancing.

Question #3: Should health conscious U.S. residents rely solely on wearing cloth masks in public places within communities experiencing high transmission of Delta in order to avoid becoming silent spreaders and to avoid contracting the virus themselves if they are vaccinated, but vulnerable?

Answer #3: Absolutely not. As will be discussed in the third note in this series, they should also employ various forms of distancing where appropriate, i.e., social distancing, self-quarantine, shelter-at-home, and compliance with lockdowns if their local governments determine that this extreme measure is unavoidable. 

Health conscious U.S. residents should wear their masks in all public places, not just in communities wherein official estimates of new infections are high. Low estimates of infections are likely to substantially undercount the true number of new infections because having no symptoms or only mild symptoms, most breakthroughs will be unlikely to volunteer to be tested, nor will they be required to undergo periodic testing.

Beyond this, health conscious residents should give serious thought to abandoning their use of cloth masks and upgrading tp more effective face coverings when they are in public places.  

• Given Delta's high transmissibility, there is ample reason to suspect that universal wearing of cloth masks in communities wherein Delta is rampant provides substantially lower reductions in new infections than cloth masks provided against previous variants.
  
  
• On the other hand, more and more residents of all communities have COVID fatigue, so they are less likely to don masks of any kind. This will further undermine cloth masks whose effectiveness depends on their being worn by "everyone". Now more than ever, health conscious members of every community need face coverings that protect them from inhaling the virus and block their exhaling the virus, regardless of what anyone else is wearing or not wearing.

Double masking 

The need for better masks during the pandemic has long been recognized. For example, the following plea for more effective masks was published in June 2020.

•  "We Need Better Masks", Ranu S. Dhillon, Abraar Karan, David Beier, and Devabhaktuni Srikrishna, Harvard Business Review, 6/18/20

When more powerful variants appeared in late 2020 and early 2021, articles appeared that cited the benefits of double masking, the easiest pairing being a cloth mask worn over a surgical mask.

• "One Mask Is Good. Would Two Be Better?", Katherine J. Wu, NY Times, 1/12/21" ... Layering two less specialized masks on top of each other can provide comparable protection.[to N95, masks]."
  
  
• "Time to double or upgrade masks as coronavirus variants emerge, experts say", Fenit Nirappil, Washington Post, 1/28/21

The CDC finally weighed into this discussion with a weak endorsement of double masking, but has not followed up with any reminders of their advantages since then, not even after the emergence of the Delta super variant.

• "Types of Masks", Centers for Disease Control, updated on 2/10/21 
  "For better fit and extra protection wear two masks: Disposable mask underneath AND cloth mask on top ... OR ... A cloth mask can be combined with a fitter or brace"

N95 ("respirators") vs. KN95 masks

The most effective face covers for protecting the wearer and those around the wearer are the N95 and KN95 masks. There are two things to keep in mind in your searches:

-- Experts agree that the N95 respirators are the gold standard, which is why they are worn by U.S. health care professionals; KN95 masks place second 

-- There are lots of fake N95 and KN95 masks being sold by unscrupulous vendors, so shop carefully.

The following articles provide useful tips that will make it easier for you to find genuine CDC approved masks. Links to additional information about masks can be found on the frequently updated "COVID masks" page on this blog.

• "N95 vs. KN95 Masks for Sale: Differences, Where to Buy", Josh Smith, Newsweek, 12/18/20
  
  
• "What’s the Difference Between N95 Masks and KN95 Masks?", Tim Chan, Rolling Stone, 2/1/21
  
  
• "How to Buy a Real N95 Mask Online", Brian X. Chen, NY Times, 2/17/21
  
  
• "Finding reliable masks online can be tricky. Here are tips that can help.", Chris Velazco, Washington Post, 8/21/21

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Related notes on this blog:

• "Downgrading the CDC's guidance", Last update: 7/25/21
  
  
• "Is the CDC misguiding us again, this time with regards to Delta breakthrough infections???", Last update: 8/13/21
  
  
• "Tracking Delta breakthroughs -- Part 1 (Three disruptive properties)", Last update:  8/22/21
  
  
• Tracking Delta breakthroughs -- Part 3 (Mitigation via distancing)", Last update: 8/30/21
  
  
• Tracking Delta breakthroughs -- Part 4 (Mitigation via testing and contact tracing)", Last update:  9/5/21