Variants – BioQuakes

“Globally, there has been a slow but steady increase in the proportion of BA.2.86 reported, with its global prevalence at 8.9% in epidemiological week 44” (WHO)

Another variant? Since the beginning of the epidemic, we have seen a few strains of COVID-19 arise, notably the Omicron, Delta, and Alpha variants. You may ask, how do these mutations keep on materializing?

Like all viruses, SARS-CoV-2 — the virus responsible for COVID-19 — goes under, and will continue to go under, several mutations.

As a coronavirus, SARS-CoV-2 uses protein spikes (visualization on right) that fit into cellular receptors, in order to infiltrate our cells. Upon entry of the virus, the invaded cell begins to translate the viral RNA into viral proteins, which leads to the production of new viral genomes. According to Akiko Awasaki, PhD, this is where mutations often arise, stating that, “When viruses enter the host cells and replicate and make copies of their genomes, they inevitably introduce some errors into the code.” While these introduced errors may be inconsequential, they can also be of benefit to the virus, increasing contagiousness. These successful mutations may change how the virus behaves in the future, becoming the foundations of new evolutionary steps.

As we learned in AP Bio, the sequence of amino acids plays a heavy role in the primary structure of the spike protein. When the sequence is altered, hydrogen bonds will be corrupted or created, affecting the stability of the secondary structures like alpha helices and beta pleated sheets. This changes will in turn affect the tertiary structure, ultimately morphing the three-dimensional shape of the spike protein.

Given this knowledge of how SARS-CoV-2 invades cells, and how it may lead to evolution and mutation, what is the significance of this newest variant, and how can it be fought?

BA.2.86 was discovered over the summer with cases from Denmark, Israel, the United Kingdom, and the United States. Later on, it spread to various countries all over the globe, being discovered in wastewater in countries such as Spain and Thailand. As weeks passed, the new strain did not seem to pose a threat compared to its predecessors. However, months later, BA.2.86 on the rise. On November 11th, the CDC estimated that 3.0% of cases came from BA.2.86. November 28th’s estimate, 8.9%, is shockingly almost triple of the earlier estimate just two weeks prior. This is apparently garnering the strain some sort of reputation, now being labelled a “variant of interest” by the World Health Organization.

While the percentage may seem scary, the rise of the strain has not brought a disproportionate growth in infections or hospitalizations. Rather than posing new or threatening danger, it seems to be much better adept to escaping our bodies’ defense systems. The improved ability to slip past antibodies, compared to previous variants, likely comes from its large number of mutations, 30, on its spike protein. Antibodies, which serve to fight these invaders, may find difficulty recognizing and defeating the new strain.

Due to the strain only taking the notice of researchers recently, there are still many things to be uncovered. Some researchers have affirmed their support in newer vaccines against BA.2.86 and future variants. As always, it is best to wear masks when necessary, wash your hands, quarantine if you are experiencing symptoms, and receive the latest vaccine.

Researchers Find Ways To Combat COVID-19

By dagambella

On January 16, 2023

In Student Post

Ever since COVID-19 was discovered scientists had no idea how to stop this virus. After lots of research we were able to know that there were many different variants of COVID-19. We understood that some variants were stronger than others according to research. There is an article that talks about how they can be able to stop all kinds of COVID-19 viruses and the different variants. In the article, Professor Seung Soo Oh had an idea on how to stop all kinds of variants in one go. He says that the virus can change its structure whenever. It will then bind to the angiotensin-converting enzyme receptor which is a receptor protein. His team developed a hybrid neutralizer that is able to bind to the virus which then cause the virus to not interact with the protein receptor. This neutralizer was able to be about 5 times more effective then what they first had when COVID-19 was discovered.

According to this article, Omicron which was found in November of 2021 in South Africa, is the most dangerous variant of COVID-19. It is a variant of COVID-19 and is one of the strongest variants. In December of 2019, sub-variants of Omicron began to appear. Some of the sub-variants include BA.5, BQ.1, and BQ.1.1. According to the article, the Omicron sub-variants were very effective and was more transmissible then the Delta variant. The neutralizer should be able to stop Omicron and the sub-variants.

According to another article, variants aren’t weakened by covid vaccines that were had a while ago. In order to help stop COVID-19, the article says that getting boosters will be more effective for any new variants that are discovered. This doesn’t mean they will 100% work. With this knowledge, the new neutralizer that was developed should be able to stop all these viruses from mutating and from entering the cell.

This relates to what we have learned in class this year because we have learned cell structure. When COVID enters the cell, it must bind to a receptor. Once it enters the cell the RNA or DNA would then reproduce. This is similar to what we have learned about how other things enter the cell such as glucose and amino acids. In receptor mediated endocytosis, the ligands must bind to the receptor and then enter the cell. This relates to what we have learned in class because we have learned how molecules are able to enter the cell and how receptors work.

SARS-CoV-2 and Our Evolving Immune Systems

By anaplasia

On December 20, 2021

In Student Post

A scientific study analyzed in a recent article by Monique Brouillette brings hope with the emergence of possibly more infectious COVID-19 variants. The study looks at the blood of people who are vaccinated, and people who recently have had COVID-19, to learn more about the cells in our immune system. Studying and seeing these cells create their own way to counteract mutations could mean the evolution of our immune systems in response to the variants. So the study poses the question: Along with our cells ability to respond to the initial SARS-CoV-2 virus invasion, do our bodies adapt so that those same cells can recognize the new variants?

An Immunologist at the Rockefeller University, Michel Nussenzweig, conducted a study along with his colleagues by testing the blood of individuals both one month and seven months after they had COVID-19. The scientists noticed that individuals had lower levels of antibodies, and equal or higher levels of memory B cells, seven months after having COVID-19 than one month after. This was expected as the virus had been fully cleared by the seven month mark, and memory B cells were created in response to the initial invasion of SARS-CoV-2.

Memory B cells are created by the humoral response. This is when macrophages or dendritic cells recognize a forign antigen (in this case SARS-CoV-2), and stay in the body near its lymph nodes with the ability to recognize the virus.

If someone were to get infected for a second time, these memory B cells would activate to quickly produce antibodies and block the virus. This is called the secondary immune response (pictured on the right).

The scientists then did another test in the study. They tested reserve B cells and antibodies someone produced in response to SARS-CoV-2 against a version of SARS-CoV-2 they created to be more like a new variant. The replica new variant virus was made to be more like the new variants by having a mutation in the spike protein, which is the part of the virus that binds to our cells. When they tested this, they saw that some reserve B cells produced antibodies that went and attached to the mutated spike proteins, showing that the reserve B cells and antibodies from SARS-CoV-2 were able to adapt and recognize a different or mutated version of SARS-CoV-2.

New COVID19 mutant (SARS-CoV-2 VOC-20201-01)

Example of SARS-CoV-2 Mutation

The SARS-CoV-2 variants have many similar elements to the original SARS-CoV-2, but also contain mutations in their spike proteins and receptor binding domains (for the most part), which allow them to usually go undetected by our bodies. This is why those who are vaccinated or have SARS-CoV-2 antibodies are not fully immune to the variants.

Most recently, Nussenzweig and his team conducted the same experiment again, but with new and improved viruses that more closely resemble the COVID-19 variants. One of the replica variants is of B.1.351, which contains mutations K417N, E484K, and N501Y, was tested against cloned six month old (previously exposed to SARS-CoV-2) B cells. Although it has not yet been reviewed and confirmed, this test did show that some of the antibodies produced by these B cells had the ability to recognize and attach to these mutated variants engineered to be very similar to the viruses of the Covid variants.

What these scientists discovered with SARS-CoV-2 is a process called somatic hypermutation. This is when the immune system adapts to recognize and attack forign mutations or viruses it has not seen before when they have previously fought off a virus with some similar elements. The occurrence of this process with SARS-CoV-2 gives us hope that after getting the vaccine or having had COVID-19, our bodies will have a better defense against the new variants, which will, hopefully, in turn, lessen the fear and stress surrounding the emergence of new SARS-CoV-2 variants.

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Variants

The “Slow but Steady” Increase of yet Another COVID-19 Variant: What are the Implications?

Another variant? Since the beginning of the epidemic, we have seen a few strains of COVID-19 arise, notably the Omicron, Delta, and Alpha variants. You may ask, how do these mutations keep on materializing?

Given this knowledge of how SARS-CoV-2 invades cells, and how it may lead to evolution and mutation, what is the significance of this newest variant, and how can it be fought?

Researchers Find Ways To Combat COVID-19

SARS-CoV-2 and Our Evolving Immune Systems

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