CAN THE VIRUS LIVE IN THE AIR?
Can COVID-19 be transmitted in the air? Should we be concerned that there may be a COVID testing center near you, or that someone had just used the gas pump that you are now using?
The best thoughts now are that the COVID-19 virus is transmitted through liquid droplets from one person to another, primarily through coughing and sneezing, and these droplets settle on surfaces within a few feet.
However, to be absolutely complete, there is a discussion in the literature that the virus may be transmitted through aerosols. Aerosols are mists where the droplets are extremely small and where those droplets do not simply settle down on surfaces within the first few feet. Some aerosols are created during coughing, sneezing or even talking. These aerosols can travel as much as 20 feet or more.
There are reports from China that some department stores showed evidence of virus at their entrances, suggesting the virus may have been in the air there. But there is a VERY important caveat here. The only tests that are currently available to look for virus looks for RNA from the virus.
This is a good time to talk about what happens when a virus particle is killed. A virus particle (specifically a coronavirus) is a piece of genetic material, in this case RNA, trapped inside a fatty bubble that has a few proteins on its surface. The entire particle, proteins, lipids (fatty envelope) and genetic material needs to be intact in order for the virus to bind to a cell, incorporate into the cell membrane and inject the RNA. If the pieces are broken apart, so that the proteins are separate from the fatty material and the RNA is loose, you cannot have an infection. It is not that in this case an infection is less likely; in fact, it is impossible.
If you separate the battery and the light bulb from the casings of your flashlight, you can’t have any light, you don’t just have a small chance of having a little light. No light at all is possible.
When the virus is killed, by drying, heat, or UV light, it is broken into its parts. Infection is now impossible.
WHAT DO TESTS ACTUALLY SHOW?
From the PCR tests that are used to test for virus, we conclude that when samples of sputum or nasal wash are taken from patients, the presence of COVID-19 RNA is determinative of the presence of virus in that patient.
But here is the really important thing to remember: We DO NOT actually test for the presence of virus. If we were to do that, the test would be to take the sample and see if it can infect cells or animals in a laboratory setting and if virus could then be recovered from the infected cells or animals. WE DO NOT DO THIS.
We test for the presence of pieces of RNA that are specific to the virus.
A good analogy is a crime scene. The detectives look for shell casings or bullet fragments. From that evidence they can determine that there was a gun used, and in some cases can determine that those shell casings and bullet fragments both came from a specific, identified gun.
BUT you cannot kill someone with the shell casings and bullet fragments. You need intact bullets fired from a functional gun.
The PCR tests currently used, look for fragments of RNA, determining that they must have come from a COVID-19 virus particle. But these fragments themselves are not infective.
There is a big difference when you test air. As discussed above, this virus is not particularly robust. It falls apart under a lot of circumstances. If the bubble it is in dries out, as in heat or the sun, the virus’ fatty envelope falls apart. If it is exposed to UV light, it is destroyed.
The tests we currently use look for the presence of RNA, not for the presence of live virus. So, when those tests at the department stores were done, and they found COVID-19 RNA present, it DID NOT mean that there was live virus there. Most likely there was killed virus with some RNA left over to be detected.
With that said, there is very little evidence that viruses can be transported for hundreds of yards and still be “viable”. What that means is that there is virtually no chance that even if the virus is aerosolized at a testing center near you, that intact virus could possibly reach you as you walk, bike or drive by.