Mar 15, 2021
The coronavirus causing the pandemic is mutating.
In the late fall, distinctive new versions of the virus led to alarming surges in Brazil, South Africa and the United Kingdom. These variants carry not one, but a slew of mutations. They appear to have worrisome new abilities, better at spreading or slipping by aspects of our immune system. All these variants have been detected in the U.S.
Scientists suspect these three variants are more contagious for three reasons: these variants are rapidly replacing other versions of the virus; they have mutations (changes to genetic make-up) that affect a part of the virus likely to be important; and some mutations have already been shown in the lab to increase the ability of the virus to infect cells. Together, these three factors build a case for a variant that spreads more easily.
It’s not unexpected that these new variants have developed. All viruses mutate as they make copies of themselves. These are accidental and random changes in the genes. Most of these differences are inconsequential. A few can even be harmful to the virus’s survival. But some changes are advantageous to the virus. They could allow the virus to infect us more efficiently, for example, or replicate more efficiently or defeat our own immune system defenses.
The genes that are helpful to the virus, or at least are not harmful to the virus, keep getting replicated. This process is called natural selection. Together, natural selection and random mutations drive evolution. All living things evolve. This is a normal, observable, and continuous process. And we are observing it right now with COVID-19.
Some scientists assumed that because the virus has a proofreading mechanism to correct errors when it multiplies, it wouldn’t mutate rapidly. But many of the changes in the virus weren’t typos in the genetic code. They were missing swaths called deletions. The virus couldn’t proofread what wasn’t there.
The virus that was first detected in Wuhan, China, is not the same one circulating today in most places around the world. There are many thousands of different versions, or variants, of COVID circulating. The three variants mentioned above are of concern to scientists because they are more contagious, and some may evade antibodies. This could make the current treatments and vaccines less effective against the virus. While the genetic code for each of these variants is slightly different, they do share some of the same mutations. These same mutations happened independently—most likely because they are so useful to the virus.
All three variants, the U.K., the South African, and the Brazilian, share the N501Y gene. This gene may help these variants spread more easily. The South African and Brazilian variant both have the E484K mutation which may affect how our antibodies respond to the virus. From the studies, it looks like it makes our antibodies less effective.
These variants have been found in the U.S. Additionally, the U.S. has its own homegrown variants: two found in California and one detected in New York. These variants are of concern, just like the other three, but more study is needed to confirm the concern of scientists. Even though variants were completely predictable, the U.S. has not spent the money or resources in searching for and studying new variants.
These variants don’t stay in one city or one country. They travel around on planes, trains, cars, buses, and cruise ships, with the often unaware host they have infected. The U.K. variant, for example, went from being non-existent to spreading to over 80 countries around the world, including the U.S.
These variants show that this global catastrophe requires global solutions. Leaving one country behind will leave us all behind.