January 13, 2022

Omicron Variant versus Delta Variant: Lessons on What to Expect From Coronavirus Adaptations

My previous blog post described how Coronavirus strains adapt and benefit from their naturally high error rate when they copy their own RNA as more virus particles are produced in an infected cell. (Click to read that posting here.) If these changes cause a particular strain to spread easier among us humans then these new strains quickly take over the infection race. There is no evil plot, just the random events of statistics and bad luck for us as variants like Omicron spread faster. Delta is still around, but Omicron gets to new unvaccinated persons first, and eventually, more of those requiring admissions to our hospitals will have Omicron and not Delta. That said, both Delta and Omicron are killing people inside our hospital ICUs. Why exactly does Omicron spread faster than Delta?

Some research clues are becoming available as laboratory-based studies are completed and their results are submitted to scientific journals for peer review.  A hint of one study not yet peer-reviewed comes from a Hong Kong University new release, that you can check out here:


From what I can read of the description on the HKU website, it seems that Omicron replicates 70 times faster than the Delta variant in the upper respiratory tract compared to the lungs, but Delta replicates faster deeper in the lungs themselves compared to Omicron. This could explain how Omicron spreads faster and more easily through shared air spaces in our schools, stores, and homes as it efficiently infects and takes hold in our sinuses and bronchial tubes. It very quickly reproduces a high viral load and so there is a very short time before we can breathe out plenty of virus to infect more persons. This would explain how, as seen in South Africa, a population will get a wave of Omicron infections very fast and also explains why less people will be able to escape infection using mitigations that were sufficient in 2020 and even for Delta in 2021. That includes looser-fitting cloth masks. My family began using N95 masks early in December 2021 for just this reason. We are also completely vaccinated. 

As far as vaccines go, Omicron is able to infect vaccinated persons easier than Delta as Omicron has changed its shape more to make it less of a good match for our antibodies to the earlier COVID19 strains. However, Omicron does not completely escape our antibodies from vaccination and we still benefit from being able to mount our own immune defenses faster to prevent most vaccinated persons from needing to go to the hospital. 

Over 90% of persons dying from COVID19 (Delta and Omicron) are unvaccinated persons. Those who are dying from COVID19 among vaccinated persons have other medical conditions and/or compromised immune systems. 

It is important to note that while Omicron kills a smaller percentage of the persons it infects compared to Delta, Omicron will kill a large total number of unvaccinated persons because it infects so many more people and does so more rapidly. That smaller percentage of many more people will still amount to a lot of people harmed by this variant. 

We cannot say it often enough. "Get vaccinated, please." Do not be afraid of vaccines. I have had flu shots for 15 years (an no flu),  two covid vaccinations, and a booster. I have 30 years of experience in the biochemistry, molecular biology, and genetics laboratory researching human disease and developing medical therapy for eye diseases. With what I have learned over three decades I decided to get vaccinated and wear my N95 so I do not get infected, and so I do not make another unfortunate person ill. Trust me, it's safe to get vaccinated and you may save your loved ones the pain of losing you or also save yourself the pain of losing them. 

Why should you listen to my advice? Well, there are lots of politicians, radio and TV hosts, and more, who sow doubt in your minds about vaccination treatment but they are not experts in any of this. Consider this. Those people are not master electricians, so would you hire them to rewire your Family's home? I replaced the electrical panel and other wiring in my house and garage last summer, upgrading for quality and safety. While I can understand basic guides to electrical installation, I hired a real master electrician to do the work properly, with no mistakes. I let him tell me the best options, not the other way around. My Ph.D. makes me an expert in biochemistry, not a master electrician. Hopefully, he similarly listened to what I know about fighting Covid19. He wore N95 masks doing his work and was obviously listening to medical experts about medicine, just as we clients listen to his expertise about electrical systems and its installation in our homes. 

Just something to ponder. Do not consider my advice because I am a master electrican, because I am not one. Consider my advice because I am a "master" in biochemistry and molecular biology.

Feel free to ask me questions, and I will always do my best to answer them. No question is a bad question. No judgments from me. You ask. I will answer. That is what science educators like me are here for.  We love to talk about our science. Really. :)

Stay safe out there. 

Ken Mitton

Associate Professor of Biomedical Sciences

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