AP Biology class blog for discussing current research in Biology

Tag: WHO

Changing Composition of SARS-CoV-2/Understanding the Alpha Variant in England

Since its emergence in the Fall of 2020, the original SARS-CoV-2 variant of concern (VOC) rapidly became the dominant lineage across much of Europe. Although, simultaneously, several other variants of concern were identified globally. Like B.1.1.7 or the Alpha Variant (first mutation of SARS-CoV-2 found to be more transmissible), these VOCs possess mutations thought to create only partial immunity.

Researchers are understanding when and how these additional VOCs pose a threat in settings where B.1.1.7 is currently dominant. This is where scientists in the UK examined trends in the prevalence of non-B.1.1.7 lineages in London and other English regions using passive-case detection PCR data, cross-sectional community infection surveys, genomic surveillance, and wastewater monitoring. The study period spanned from January 31st of 2021 to May 15th of 2021.

Through this data, the percentage of non-B.1.1.7 variants has been increasing since late March 2021. This increase was initially driven by a variety of lineages with immune escape. From mid-April, B.1.617.2 (WHO label of Delta) spread rapidly, becoming the dominant variant in England by late May, similarly to the Alpha Variant.

Shown by many mutations in the spike protein receptor (RBD), studies suggest B.1.1.7 is 50–80% more transmissible with greater severity than previously circulating Covid Variants. B.1.1.7 rose rapidly, from near 0% to over 50% in under two months, and soon made up greater than 98% of sequenced samples in England. Its rapid spread necessitated a third lockdown in England during last January. Subsequent spread in Europe and North America has highlighted the threat this variant poses to a continued alteration of the Coronavirus.

The 69–70 deletion in B.1.1.7′s Spike gene causes PCR tests to return negative results for that gene target which is a major problem when identifying and testing for Covid. One of the most important changes in lineage of B.1.1.7 seems to be a spike protein substitution of N501Y, a change from asparagine to tyrosine in amino-acid position, that enhances transmission. These alterations can change antibody recognition while also affecting ACE2’s (receptor protein) binding specificity which can then lead to the virus becoming more infectious. We are seeing a pattern of the same type of mutation in Covid consistently.

An example of a similar mutation that has been recent is the new Omicron variant out of South Africa. Omicron is similar in which their has been a specific change in the spike protein where antibody recognition is limited and it is highly transmissible between any living organism. Our class has understood and studied the importance of our body being able to identify and create an antibody for the specific antigen being displayed by a pathogen.  These mutations within the spike protein allow another immune response to happen which a different antibody has to be created to mark the different antigen being displayed. Unfortunately, this will be a continuing problem without vaccine mandates since it gives the virus more time to mutate where outbreaks like in South Africa will continue to transpire around the world.

How Is Covid- 19 Really Spread?

Background- It is clear that Covid- 19 has been a fatal and vicious virus causing a pandemic, but how is it actually spread? The answer to that question can be found in the World Health Organization’s article titled “Coronavirus disease (COVID-19): How is it transmitted?”.  The article discusses how the SARS-CoV-2 virus, commonly known as the Coronavirus, is spread between people. First, lets quickly zoom into the biological elements of transmission. On a cellular level, the outside of a coronavirus molecule is a spike protein which latches on to specific receptors that fuse it into human cells. The proteins “trick” the human cells into letting them enter and infect them. Once in the healthy cell, the virus spreads its genetic material and spreads throughout your body.

When/Where can the virus spread more easily?- The risk of transmission is highest when people are in close proximity to others for a long period of time. The World Health Organization, or WHO, describes that the more people in a group, the more likely the virus will spread. Any crowded spaces, close contact, or confined spaces with a lack of ventilation. Additionally, it has been found that people are most contagious early on in their illness, although this can range person- to- person.

Transmission of virus via liquid particles – The WHO claims that one way in which a person can transmit the virus is through small liquid particles spread by coughing, sneezing, speaking, or even just breathing. The liquid particles, most commonly respiratory droplets, vary in size, and transmit the virus from person to person. When in close contact with someone with the virus– less than six feet– you can catch the virus through your mouth, nose, or eyes.

Aerosol transmission- Aerosol transmission is when the virus travels through particles in the air to infect people. This transmission is most likely to occur indoors, and particularly in crowded spaces with a lack of ventilation.

What is really important that we understand about transmission is how this virus transmits, meaning how does this virus move from one individual to another?- Dr Maria Van Kerkhove

My Opinion- I think it is super important to educate yourself on how the virus spreads from person- to- person in order to avoid the situations in which transmission is most likely. Further, it is rather interesting to learn about how the virus enters your cells, and biologically infects your body.

I would love to hear your reactions or thoughts in the comments!

Pneumonia Outbreak in China: What You Should Know.

Weeks before the starting of 2020, a mysterious case of pneumonia seemingly caused by a contagious virus broke in Wuhan, China. The outbreak occurred in a local fish market which sold the meat of various exotic animals. The fascinating thing about this strange case is that scientists were unable to link it to previously known about pathogens such as SARS, MERS, or influenza. The true culprit of the spreading infection remained a mystery until scientists were able to analyze the genetic code of what they believed was the virus causing the panic.

A New Coronavirus

On January 10th the DNA Genome of the virus was recorded and scientists were finally able to identify the virus as a pathogen known as a “coronavirus“. Coronaviruses are fairly common and spread all types of illnesses from the common cold to severe acute respiratory syndrome or SARS. China and the world at large have actually gotten pretty familiar with handling these types of diseases as a global outbreak of SARS that originated in China occurred in 2003, barely a decade before the emergence of this new coronavirus. Thanks to this SARS outbreak, which infected 8,000 people and killed nearly 800, China has since had a very cautionary culture when it comes to medical issues. It is not uncommon to see people wearing medical masks regularly in public in order to prevent contamination in the highly populated areas of China. One can assume that this culture in China has helped with the current outbreak’s speedy treatment.

Effects and Outcomes

As a result of the spreading of the virus in the seafood supermarket, 59 patients were brought to the hospital, seven of which were in critical condition. It is known that coronaviruses all come from animal to human transmission so it is no surprise that the virus would appear so rapidly in an area where many humans interact with many animals. Since the outbreak, this market has been closed as of January 1st to few’s surprise. However, it is sad to say that the virus has claimed the life of a 61 year old man how seemingly was weak from many other ailments from his old age. While the newfound coronavirus has been proven to be deadly, many medical professionals and The WHO (World Health Organization) say there should be no cause for great concern as the outbreak has seemingly been contained since late December and there are no true prospects of it becoming a world like epidemic like SARS in 2003. Nonetheless, this recent case of pathological disease spreading serves as a reminder of the deadly forces we must all be careful of every day.

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