I’m still not a doctor. So, on these posts you’ll never hear my opinion about anything medically-related. All I will do is cultivate and distribute medical data from real, actual doctors. Because while I didn’t get a medical degree… I can read!
Okay, Let’s Science!
Special nod to Dakota Smith, there, who hosted “Okay, Let’s Science” on Youtube.
Dr. Rich Davis is the Clinical Microbiology Lab Director at Providence Sacred Heart in Spokane, Washington. He ran an experiment to attempt to show the difference between wearing a mask and not wearing a mask when investigating droplet density.
What does a mask do? Blocks respiratory droplets coming from your mouth and throat.
Two simple demos:
First, I sneezed, sang, talked & coughed toward an agar culture plate with or without a mask. Bacteria colonies show where droplets landed. A mask blocks virtually all of them. pic.twitter.com/ETUD9DFmgU
— Rich Davis, PhD, D(ABMM), MLS 🦠🔬🧫 (@richdavisphd) June 26, 2020
The experiment was reproduced and put on the local news, too. You can watch that story here.
Of note, this is not a test that shows how much COVID-19 is distributed. Instead, Davis is using bacteria as a “proxy” for droplets. Since bacteria only escapes your mouth riding along the wter droplets that are expelled when talking, coughing, sneezing or yelling / singing.
And droplets are the things that also carry COVID-19 when a person is infected.
There is some research that has been released that questions the overall effectiveness of mask wearing. I’m not blind to that. In fact, a paper titled, “Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings” where the authors found…
“Evidence on mask effectiveness for respiratory infection prevention is stronger in health care than community settings. N95 respirators might reduce SARS-CoV-1 risk versus surgical masks in health care settings, but applicability to SARS-CoV-2 is uncertain.”
But we always need to remember Occam’s razor. And I’m betting that even if you said, “Occam’s what?!” you already know about it without knowing what it is called.
From Encyclopedia Brittanica:
Occam’s razor, also spelled Ockham’s razor, also called law of economy or law of parsimony, principle stated by the Scholastic philosopher William of Ockham (1285–1347/49) that pluralitas non est ponenda sine necessitate, “plurality should not be posited without necessity.” The principle gives precedence to simplicity: of two competing theories, the simpler explanation of an entity is to be preferred.
And, simply put, if you wearing a mask over your mouth and cough, fewer droplets escape. And thus fewer COVID-19 viruses escape, too.
Is it perfect? Nope. Not by a long shot.
Is wearing a mask more effective at stopping droplets than not wearing a mask? Totally.
In fact, the research I pointed out the other day suggested that masks can reduce the transmission of COVID-19 by more than 70-percent.
False-negative tests continue to be problematic
In a paper titled, “Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction–Based SARS-CoV-2 Tests by Time Since Exposure” the authors investigate how often infected people are tested yet test negative. The authors looked at seven previously published studies’ data on “RT-PCR performance by time since symptom onset or SARS-CoV-2 exposure using samples from the upper respiratory tract.”
The sample size ended up being 1330 people.
Over the 4 days of infection before the typical time of symptom onset (day 5), the probability of a false-negative result in an infected person decreases from 100% (95% CI, 100% to 100%) on day 1 to 67% (CI, 27% to 94%) on day 4. On the day of symptom onset, the median false-negative rate was 38% (CI, 18% to 65%). This decreased to 20% (CI, 12% to 30%) on day 8 (3 days after symptom onset) then began to increase again, from 21% (CI, 13% to 31%) on day 9 to 66% (CI, 54% to 77%) on day 21.
What this is showing is that four days after becoming infected about 2/3rds of people were still registering as “not infected” when tested. On top of that, even when people became symptomatic, nearly four out of every 10 people were still testing negative.
The concern here is that people are testing negative, and go about their business like they have the common cold or the flu. Most people spend a few days trying to recover and then get back to work, even if they feel sluggish or still sick. Because with most “bugs” people get, the common train of thought is you spend a few days recovering and then once the fever subsides, you are no longer contagious.
But that is not the case with COVID-19. As we’ve seen through multiple papers and research, asymptomatic people are likely the biggest transmitters of the virus.
And this really makes another case for why the medical community says wearing a mask – no matter who you are or how sick you may feel – is so important.
Anecdotally, I am aware of two people who have been tested multiple times for COVID-19 and come back negative each time. One was sick for two weeks, then better for about a week, and then sick again for another two weeks. That person exhibited all the symptoms of COVID-19, but continued to test negative. So, again anecdotally, I have seen evidence of people becoming sick with all of the “signs” of COVID without actually testing positive.
As a brief subscript to this, some people seem to be sharing those posts that claim many of the positive cases being tallied are people with colds, or broken arms, or people in car wrecks. Firstly, there is no evidence of that. Secondly, with how many false-negatives that are potentially happening, it is likely the numbers of new cases and being under-reported, not over-reported. There is evidence of that, shown by the research above.
I’m not going to try to stop conspiracy theorists from conspiracy theorizing. It is a free country, after all. I will only point out to those who are interested that evidence is an important piece of the puzzle when trying to explain what it objectively verifiable as truth. Without evidence, there is only conjecture.
Nurse fact-checks O2 & CO2 levels
I ran across a video on Twitter from a nurse wearing multiple masks trying to highlight that while it may ‘feel’ more difficult to breath with a mask on, the end result is unchanged.
Great look at how wearing a mask is not going to impact your oxygen levels. Nor CO2 levels.
Also… Does anyone know how this is? This video has been shared a lot and I'd love to give credit to the actual person who is actually in this video. pic.twitter.com/WBJ965dWNa
— Nick Lilja (@NickLilja) June 27, 2020
This is a great example showing that “feelings” and “facts” are often different. And why using science to investigate feelings are so important. It may “feel” like you cant get enough air with a mask on, but the good news is that if you breath normally, your body can’t tell the difference. And there is evidence of that!
Comparing the different masks across the board, the CDC notes that the N95 masks do the best, obviously. But, more importantly, the post floating around facebook suggesting that masks don’t help is mostly false.
Snopes has a great breakdown, that I checked and can’t really improve upon… so you can head there. Say what you want about the site, but in this case, it is well done and unbiased.
How are vaccines coming?
The Mayo Clinic produced a video about the vaccines in testing now. You can find that hour-long video here.
In short, it was noted that there are many vaccines in the works. Some are further along than others, but there are pretty stringent guidelines for what can be given the “OK” from the FDA for widespread use. As we saw with hydroxochloroquine, it is important not to jump to conclusions too early.
During the video, it was discussed that vaccines are most effective when previous infection produces immunity. That is to say that the antibodies that your body develops to fight off the infection stick around for the rest of your life. So the next time a virus shows up, your antibodies are there to fight it off.
The real goal is to find the antigen that the antibodies produce and then use that antigen in the vaccine.
Multiple different rounds of research show that people do develop antibodies against COVID-19. So that is good news. However, as we learned recently, there is a question about how long those antibodies stick around. So this vaccine may need a “booster” after a certain period of time. But how long, when and how much are still being researched.
Bottom Line
Follow the CDC guidelines as best as possible. Limit your time in public, practice social distancing, wear a mask, and wash your hands!
