August 2, 2021
It seems like the media is doing a pretty poor job explaining the science of viral transmission that is behind our evolving Covid-19 crisis. I’m writing this to help people understand why the Delta variant is a game-changer requiring more intensive prevention actions. I am not an expert, but I think I have a pretty clear understanding of the mechanics of viral transmission. If I seriously mis-characterize anything, I’m sure some healthcare professionals can set us straight.
I think everyone is aware that the concentration / quantity of particles often make a huge difference. Oxygen at high elevations is more rarified, making breathing and exertion more difficult. Viral transmission has everything to do with the concentration / quantity of viral particles entering your respiratory system. The more particles you breathe in, the more likely it is that a virus will overpower your immune system and replicate in your body.
This is the point of masks and social distancing – to reduce the concentration of viral particles you are exposed to from infected people around you.
Here are some facts that aren’t always emphasized in media reports.
- As long as the global Covid-19 pandemic continues, new variants will arise, and spread globally.
- We will need booster vaccinations – this is a matter of when, not if.
- Variants will arise that seriously sicken and kill even the vaccinated. It would be a miracle if this did not happen.
There is one aspect of the Delta variant that explains both its prominence and the concern healthcare professionals are showing: it infects and replicates much more efficiently.
THE DELTA VARIANT INFECTS AND REPLICATES MUCH MORE EFFICIENTLY. The implications:
- It takes fewer viral particles to infect a body and gain a foothold.
- Once a body is infected, the quantity of virus in the body – the viral load – increases rapidly, even in fully mRNA vaccinated people.
- The higher the viral load in a person’s body, the more virus the person will expel through the nose and mouth, infecting others. Even fully mRNA vaccinated people who get infected can spread the virus to those around them.
The vaccines are safe. Over 339 million vaccine doses were given to 187.2 million people in the US as of July 19, 2021. Three deaths appear to be linked to blood clots that occurred after people got the J&J vaccine. The potential for that side effect is now known, and can be treated.
The primary purpose of vaccines is to reduce the likelihood of symptomatic illness and death. American vaccines do that well. As recently reported, fully vaccinated people account for less than 0.01% of Covid-19 hospitalizations.
However, the vaccines aren’t a cure once an unvaccinated person is infected, and don’t prevent the vaccinated from becoming infected – called breakthrough infections.
Recent data indicates that Delta breakthrough infections in fully vaccinated people can generate a viral load as great as that found in unvaccinated people, even if the infected person has few symptoms. These fully vaccinated, infected persons will expel the virus, potentially infecting other people.
Because the virus spreads via droplets expelled from the mouth and nose, any physical barrier covering the mouth and nose will reduce the number of droplets expelled into the air, and reduce the risk of infecting other people.
A quality mask that leaves no gaps around the edges can also reduce the amount of droplets you breathe in, reducing the chance you become infected when exposed to the virus by others around you. Protecting yourself is especially important if you live with vulnerable people – unvaccinated children, people over age 65, and people with weak immune systems, for example.
I wear a washable 3-layer cotton mask that includes a replaceable filter in the middle, with a nose piece that allows the mask to fit tightly all the way around. Also, Amazon seems to have a ready supply of N95 masks that lack an exhalation valve. If my occupation put me in contact with many people daily, that is what I would want to wear.
Because the Delta variant is so infectious, the wise thing to do is to always wear a quality mask when around other unknown people indoors, or even outdoors in crowds of other people. This is now a CDC recommendation.
While this data is still being vetted, Pfizer recently reported that a third dose of their mRNA vaccine increases the level of active antibodies in working age adults five times, and in the 65+ age group eleven times.1 Increased levels of antibodies result in the body carrying lower viral loads, with a lower chance that the infected person would infect others. If the Pfizer findings are confirmed, I suspect that the third dose will be recommended, especially for vulnerable populations.
I personally plan to get a third shot or booster shot when available.
The highly infectious Delta variant is a game changer. Infections, hospitalizations and deaths are on the rise again, almost exclusively among unvaccinated people. The American Covid-19 epidemic is now an epidemic of the unvaccinated.
If you care about your own health and well-being or that of others including the people you live with, you will make the effort to get – and stay – fully vaccinated.
References:
https://www.cnn.com/2021/07/30/health/delta-variant-covid-19-questions-answered/index.html
https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/sars-cov-2-transmission.html
https://covid-101.org/science/how-many-people-have-died-from-the-vaccine-in-the-u-s/
1 Is the age-related difference due to the naturally weaker immune system in older adults, or indicative of absolute antibody volumes for some other reason?