In February of 2020 I had a meeting with a colleague at a New York Presbyterian facility in Manhattan. I was aware of the COVID virus from the article in NEJM in late January and thus had gloves, a mask, glasses and alcohol. I did this because I took the train in and down to lower Manhattan. I sat in the lobby and it was jammed with patients. I sat next to the door, it was winter and the air flowed in an out as the patients arrived. Upon exiting I met a patient who was Greek and had an issue, Speaking Greek I tried to assist. I warned him of the impending pandemic. His daughter was an infections disease doc in NY. He called her and she affirmed my concern, and he went off to protect himself. It would be less than a month before all hell broke loose. But even then I knew this pathogen was airborne.
This is a well written and comprehensive work describing the airborne paths of pathogen entry into humans. The authors approach is to present a very readable set of tales of researchers who have worked to demonstrate the airborne mechanism. By airborne, it is more than just a sneeze in front of a target. It is the proliferation of pathogens in the sir over long distances and the process whereby target become infected by this diffuse set of pathogens.
The author builds the tale of air transmission in a back and forth battle between advocates and opponents. The rather normal process of scientific discovery. The old concept of a miasma, or bad air, had been reinvented to include airborne pathogens. Namely an infected person expels small packets of encapsulated pathogens by a variety of means including just normal breathing. These packets are so small that they “float” for quite a bit rather than just dropping. The packets are not like a canon ball, dropping to the ground in a short distance. But the have a counter force such as that applied by Stokes Law and even more so by the nature of the transport mechanism. They float in a Brownian motion collage, a mixture that moves and remains waiting for its victim. Proving that fact was at the heart of the authors tale.
What is surprising is that airborne transmission should have been obvious. The phenomenon of Brownian motion, the dust particles seen floating in the air on a sunny day, are clear proof of the phenomenon. Thus the authors excellent discussion of the doubters seems like people who were ignorant of basis physics.
One should consider the systems involved in disease transmission. Specifically:
1. The pathogen. Some form of micro-organism. In the case of COVID the pathogen is a corona virus, a single stranded mRNA in a package.
2. The transmission packaging. The pathogen may be unpackaged or enveloped in some manner
3. The vector. Namely the means whereby the pathogen gets from its source to the target. This may be via a carriers such as a bat, mosquito, a flea. Namely an entity that facilitates the transport and insertion of the pathogen to the target. Or as this book states the vector may be the air, where a coated pathogen gets released from an infected source and randomly finds 9ts way to a target.
4. The pathogen insertion mechanism. A mosquito bite or some packaged pathogen attaching itself to some part of the target amenable to systemic entry. In the COVID case the insertion mechanism is via the respiratory system, namely via the mouth, the nose or the eyes.
5. The pathogen activation mechanism. The pathogen must be able to enter the target cells and become activated. Thus in COVID it is the attachment to the cell surface protein ACE2 receptor. But in COVID the protein on the virus surface is temperature sensitive and thus may attach early on in the airway at lower temperatures or deeper down at higher temperatures.
There are a variety of pathogens, a multiplicity of vector methods, and equally a variety of insertion and activation means. HIV is via sexual contact or blood transmission, Rabies by animal bites, tetanus via cuts. But many vector processes are airborne mechanisms.
It would have been helpful if the author had somehow included this total process, understood somewhat now, but critical to understanding pathogen transmission and activation.
The author eventually comes up to the process as applies to COVID.
Masks have been a major stumbling block of COVID and a key element of understanding airborne transmission. For example:
1. Most masks are useless. Those skimpy blue paper masks are open on the side and do not prevent an infested person from contaminating the air nor does it protect a well person from inhaling the pathogen. N95 does work if and only if properly work.
2. Masks are useless with beards! Beards collect a massive amount of pathogens and a mask over one is useless for obvious reasons.
3. Masks at best protect the nose and mouth. However the eyes are like the sails on a ship. The cornea is coated with water and an oil substance on top of the water to protect drying out. Thus pathogens slam into this oily substance are washed down the tear duct to the respiratory system and then on their way! Thus it is essential that total eye coverage is necessary. Not just a mask.
The author does go through some of the mask work but there is a great deal missing. Despite this fact frankly the issues are still poorly understood. Recent studies state that the encapsulated Corona virus of COVID is less than 4.5 um in size. Some are less than 0.5 um. But the virion is encapsulated most likely in water molecules if not a mix of proteins. The physics of the particle is complex. But the virus alone is about 20-500 nm in diameter. Thus one may ask how many virions are in a complex bundle? Not to mention what is the structure of that bundle. Finally as we get to nano levels all sorts of electrical phenomenon occur regarding particle adhesion and repulsion. In summary much is unknown about this process.
Finally the author has a balanced discussion regarding the latest COVID pandemic. It appears that the Government was as expected political and unprepared. The vaccine is not akin to say smallpox or polio. The vaccine is at best kind of like a flu vaccine. It works somewhat for the most part. It does not prevent the infection nor its spread. It may mitigate severe responses at best. In addition the single stranded mRNA virion is subject to multiple mutations which was well known from the start. Knowing airborne transmission may very well have impacted strategies.
Overall the book is well written. It details many of the issues. Definitely worth a read. Unfortunately there are still a wealth of unanswered questions and there is still too political an environment. The next pandemic may not be far away!
Posts
