COWPOX
You have probably never heard of Benjamin Jesty. He was a dairy farmer in England in the mid 18th century. Dairy farmers often had to deal with diseases in their cows. One of those diseases resulted in cows developing pustules (swollen patches of skin filled with pus, like a pimple) on their udders. This disease was called cowpox and for farmers and milkmaids who were in close contact to those cows, they would at times develop their own disease, but other than sores on their hands and arms, they experienced only mild symptoms.
Farmer Jesty decided to take the pus from these sores on his cows and inject them into his family. The result was that his family remained healthy during the next outbreak of smallpox. Remember that smallpox was more infectious than COVID-19 and had a lethality rate of 30%. Millions died each year from this disease.
On May 14, 1796, Edward Jenner, an English physician repeated the work of Mr. Jesty. He inoculated James Phipps, an 8-year-old boy with material from a cowpox lesion obtained from the milkmaid Sarah Nelms. Although Phipps became mildly ill, he fully recovered. In July that year, Dr. Jenner inoculated Phipps with the material from a smallpox lesion. He did not develop any disease. Dr. Jenner followed this study up with 22 more individuals, all of whom were then protected from smallpox.
This process of inoculating individuals with the material from cowpox lesions was termed “vaccination” (derived from the Latin “vacca” for cow).
The important observation from these studies is that inoculating someone with a virus that causes mild disease but is highly related to a different virus that causes severe disease can be successful in allowing the body to develop immunological defenses against the more severe disease. This is the basis for many of our common vaccines that are grouped under the term “attenuated”.
Flumist is one of many available flu vaccines. In this case the vaccine is a live, attenuated virus that is applied through a swab in the nose. One of the potential benefits of this model is that the infection created in the individual (usually a child) is extremely mild, if noticed at all, but may also spread to other close contacts. That spread results in those individuals becoming immunized also.
MAGNETS
Think about a jar filled with little red spherical magnets. In the middle of the jar are a few pieces of iron rods. The rods will be covered in red balls. Even if you shake the jar so that the rods become free, once you put the jar down, the magnetic balls will all compete to bind to those rods again.
Now imagine that you add a few new yellow magnetic balls, exactly the same size and shape of the original ones, but with a stronger magnetic force on them. Now, you shake the jar and free the rods as before, but when you set the jar down, the yellow magnetic balls have now replaced the red ones on the rods. The stronger forces of the yellow balls have allowed them to win the competition for the sites on the iron rods.
This is a good analogy to how new emerging variants of COVID-19 (or any other virus) take over the universe of infections. The stronger binding force of the Spike protein on the new variant allows that virus variant a competitive advantage over pre-existing variants. When we hear about an “increased transmissibility”, it is often because of this stronger binding force of the Spike protein.
SO, WHAT ABOUT OMICRON?
Well, it does appear that this new variant may be more transmissible than current circulating variants including Delta. The empirical observations that Omicron has been found in dozens of locations suggest that it MAY have a stronger binding energy and a competitive advantage over other circulating variants of COVID-19.
The potential GOOD NEWS is that, at least till now, there has not been no indication that Omicron is more lethal than Delta.
Omicron is an interesting variant in that it has multiple mutations in its genome, far many more than one normally expects to see in emerging variants. There are at least 10 separate changes in the amino acid sequence of the Spike Protein itself. It is surprising that such a variant would emerge, and one possible explanation is that this virus had been circulating for months within a single individual and acquired all these mutations during that long-term illness. There is hope that the process of mutating over and over within a single person before emergence into the public MAY have resulted in a virus variant that had both a better ability to bind to cells and therefore, like the magnetic balls, became the dominant virus in that individual and that it was less lethal, did not kill that individual.
If those events turn out to be true, then it is possible that Omicron may have two very important properties. First, it may be more transmissible, and like the yellow magnetic balls, will become the dominant strain across the world. And second, it may, like cowpox, result in a milder infection that still protects against the severe disease of Delta.
If those events occur, we will be on the road to worldwide recovery. Vaccination, mask-wearing, careful social activities, and replacement of a dangerous virus with a milder variant can combine to lead us out of this dark period.