AP Biology class blog for discussing current research in Biology

Tag: long covid

Covid Brain Fog

COVID BRAIN? That’s a thing? Yes. Within the metaphorical shadow of an ice sheet, “brain fog” has evolved into a comprehensive label, encompassing the intricate cognitive, psychological, and emotional struggles intertwined with long COVID.3D medical animation coronavirus structure

The referenced article shares the story of Kenton Kaplan, a senior in the Edmund A. Walsh School of Foreign Service at Georgetown University, showing signs of COVID-related brain symptoms. Ken’s year-long battle with severe memory loss, extreme fatigue, and immunosuppression highlights the diverse experiences enclosed by this term. Despite its recognition as a federally acknowledged disability, individuals reporting “brain fog” face disbelief, hindering their access to necessary accommodations. 

Emily Mendenhall, a medical anthropologist, explored the varied manifestations of long COVID symptoms beyond the popular definition of mild forgetfulness. Interviews with 22 sufferers revealed debilitating episodes, with individuals describing struggles with daily tasks during “brain fog” episodes. These individuals spoke of debilitating days where routine tasks became overwhelming: chronic nerve pain, severe headaches, episodes of dizziness, nausea, and fainting. The disparity between how healthcare professionals perceive “brain fog” and the actual experiences of those affected emphasizes the necessity for clear categorizations that can more effectively address the range and intensity of symptoms. 

Faced with difficulties in securing accommodations, Ken’s ongoing struggles with sporadic memory loss emphasize the importance of acknowledging the complexity of a cloudy consciousness. Clearer names and understanding the various aspects of symptoms could help make medical leave and accommodations more accepted. This support would be beneficial for those dealing with the continued effects of long COVID in their everyday lives.

When the immune system encounters specific pathogens, such as the COVID-19 virus, it relies on the binding action of B cell antigen receptors or antibodies to epitopes on the pathogen for recognition. This recognition serves as a trigger, setting off a cascade of events that activate B cells and stimulate the production of antibodies. These antibodies play a crucial role in safeguarding the body against the virus. This shows how important a strong immune system is in dealing with complicated conditions like long COVID, especially when it comes to cognitive challenges like “brain fog.”

A couple of weeks ago, my mom tested positive for COVID, marking the first time she had ever faced the virus since the beginning of the pandemic. Despite being up to date on all her vaccines, including mRNA shots, which introduce genetic material into cells to prompt the production of viral proteins and trigger the immune system, she still experienced a severe case. Unfortunately, COVID hit her hard, unleashing a wave of symptoms ranging from chills and fever to body aches, a runny nose, and a persistent cough. As if that wasn’t challenging enough, she started experiencing heightened anxiety as she struggled with memory lapses, struggling to recall the day she tested positive, losing track of time, and questioning how long she had been in quarantine. It was a tough period for her, navigating not only the physical toll of the illness but also the mental strain of uncertainty. So, how can we collectively raise awareness about the diverse experiences encapsulated by the term “brain fog” and advocate for better understanding and support?

Is Long COVID-Induced Brain Fog Also Related to Blood Clots?

-As learned in AP Biology, the virus that causes COVID-19 is the SARS-CoV-2 virus. It has spike proteins attached to it that bind to the ACE2 receptors on our healthy cells which allow the virus to fuse with them. The viral envelope attaches to the membranes of our cells and then releases its genetic information to the inside of them. Its RNA hijacks the cells and instructs its machinery to create more virus particles, causing it to further infect the body.

Novel Coronavirus SARS-CoV-2

Shown above: SARS-CoV-2 virus with spike proteins attached.

After suffering from COVID-19, many people have experienced a condition called long COVID. Long COVID is a condition that causes either new or previously experienced symptoms from the COVID-19 virus to develop and linger for weeks, months, or even years after recovery. While scientists are constantly discovering more about the condition, they are still not completely sure what causes it. The variety of symptoms in addition to the lack of understanding regarding this topic result in the inability to properly treat the condition as a whole. Instead, doctors usually treat the symptoms individually and specifically to the patient. Some symptoms include chronic pain, shortness of breath, chest pain, intense fatigue, and brain fog. New research shows that long COVID-induced brain fog could possibly be linked to blood clots.

Data were collected from about 1840 unvaccinated adults in the UK who were hospitalized due to severe COVID symptoms. The patients provided blood samples when initially hospitalized, 6 months after hospitalization, and 1 year after hospitalization. They also completed cognitive tests and filled out questionnaires.

Blood clotting is a process that prevents uncontrolled blood loss when a blood vessel is injured. A type of blood cell called platelets combine with proteins in the plasma to form a clot over the injury. However, sometimes blood clots do not dissolve naturally or they can form when there is no injury, which can be very dangerous. Fibrinogen and D-dimer are two proteins involved in blood clotting, which were also later predicted to be linked to brain fog. Fibrinogen is created by the liver and is one of the main components in the formation of blood clots. D-dimer is a protein fragment that is released when the blood clot breaks down. People with more severe COVID cases and higher levels of fibrinogen proved to have worse memory and attention skills and overall rated their cognition more poorly on surveys. People with higher D-dimer levels also rated their cognition as poor and showed to have more trouble going back to work six to 12 months after recovery.

Figure 16.4.4 : Blood Clot

These proteins have already been linked to COVID-19 and fibrinogen has been linked to cognitive issues but scientists are still not completely sure how the proteins cause brain fog in long COVID. Dr. Maxime Taquet, a clinical psychiatrist at the University of Oxford, suspects that the blood clots could be blocking blood flow to the brain or directly interacting with nerve cells. Scientists wonder whether medicines used to treat blood clotting, such as blood thinners, could possibly reduce brain fog and other cognitive issues.

While I have not gotten an official diagnosis, I am very curious about long COVID because I experience many of the symptoms. I’ve had a lasting cough, brain fog, and reflux. Do you or have you ever experienced long COVID symptoms?

What Impact Can Covid-19 Have on You? How Long Will It Last?

The University of Melbourne conducted a study, from January 2020 to October 2022 that involved over 12,000 participants. The study examined long COVID’s ability to last, and its correlation with different SARS-CoV-2 variants. The results showed a clear trend, where nearly 40% of individuals who had contracted COVID-19 had reported persisting symptoms associated with long COVID. The study observed a lessoning likelihood of COVID-19 causing lasting symptoms as the pandemic advanced. It was also revealed that individuals infected by the more recent Omicron variant were less prone to developing long COVID, with only 12% reporting persisting symptoms.


The study also revealed some demographic factors that influenced long COVID risk. Notably, women, individuals aged 40-49, and those with a history of chronic illness, anxiety, depression, or severe COVID-19 were identified as being at a higher risk for long COVID. In addition, the decrease in long COVID with newer strains did not appear to be solely attributed to vaccination rates, suggesting the involvement of other contributing factors. This new understanding of long COVID could pave the way for further exploration, offering insights into immunological and autoimmune mechanisms, and potentially shaping broader health research. Furthermore, the impact of long COVID, has caused 36 million people to still feel unwell up to weeks, months, and even years after contracting COVID-19.

Overall, the study underscores the widespread impact of long COVID, emphasizing the need for refined strategies in prevention, treatment, and support for individuals grappling with lasting symptoms after a COVID-19 infection. The evolving nature of the virus and its varying impact on different demographic groups highlight the importance of ongoing research to enhance our understanding and response to the long-term effects of COVID-19.

In AP Bio, we recently learned about the body’s immune system. The immune system is a complex network of cells that work together to protect the body from harmful pathogens. When a virus enters the body, phagocytic cells, like macrophages and dendritic cells, engulf the virus particles through phagocytosis.
Then, the virus is broken down into small peices. These pieces are presented on the cell surface as antigens. Those viral antigens are then presented to the helper T cells and once the helper T cells bind to the viral antigen, they become activated. Then the activated helper T cells release cytokines which starts the immune response and activated the other cells. The newly activated cells are helper B cells, cytotoxic T cells, and Memory B and T cells. The helper B cells have receptors that are specific to the viral antigens so they can directly recognize the virus. These cells begin to multiply. The cytotoxic T cells are able to directly kill the already infected cells, stopping the spread of the virus. They do this by releasing perforin into the cell, which tells the cell’s lysosomes to burst so the cell gets destroyed from the inside out. In addition there are plasma B cells which prevent the virus from infecting anymore cells. Then the memory cells remember the virus’ specific antigens so if the same virus infects again in the future, a faster response can be launched.

The immune system’s ability to recognise, combat, and remember viruses is what allows us to survive.

I chose this topic because one of my math teachers said he had long COVID and it was absolutely miserable so I wanted to learn more about it.

What is changing in the immune system that allows COVID-19 systems to persist in some and not others?


Blood Clotting Proteins Predicting Signs of Long COVID

Many individuals experience sickness after they have already been cured of COVID. This is called long COVID, symptoms include cognitive problems also referred to as brain fog. Having these issues leads to a decreases in memory and concentration making it harder to function in everyday life. Now imagine still feeling sick even though you really are not sick with the virus, not a good feeling. These symptoms are now believed to come from blood clots triggered by the virus. The blood clots leave behind proteins in the blood so researchers are able to find and diagnosis patients who think they have symptoms after they have had COVID.

A study by Nature Medicine found that blood tests could point signs of long COVID. 15 % of people who contracted the virus develop long COVID symptoms. Symptoms of long COVID could last for months and possibly even years. This condition is difficult to treat and diagnose due to the wide range of symptoms it causes. These symptoms include brain fog, chest pain, dizziness, and joint pains. We all know what it is like having these pains so are able to understand how difficult it is to go through your everyday life with long COVID. Scientists are still trying to figure out if the virus stick around in the body or if it leads to other reaction, like having an autoimmune response.

The lead researcher Maxime Taquet, along with others from the University of Oxford, conducted an experiment in the United Kingdom. They tracked over 1,800 hospitalized COVID patients between the years 2020 and 2021. After six and twelve months the scientists conducted cognitive assessments and took blood samples. These are tests you still want to do good on. The blood tests revealed that the patients dealing with brain fog had specific proteins in their blood, proteins that we all have in common. The first protein is called D-dimer, which is present when blood clots breakdown. The patients with this protein did not do poorly on their cognitive tests so their memory and concentration is in tact. On the other hand these patients experience shortness of breath. This could be a sign the blood clots are taking place in the lungs causing the brain to not get enough oxygen levels. The second protein found in some patients is called fibrinogen. This protein is synthesized in the liver and stops bleeding. The patients who had this protein complained about memory impairment and sadly they also did not do well on the cognitive test.


D-dimer Formation

Another test was conducted, analyzing around 50,000 people in the United States looking for D-dimer and fibrinogen. Higher D-dimer levels were only found in people who previously had COVID, while high levels of fibrinogen correlated with brain fog whether or not a person previously had COVID. This indicates that fibrinogen is involved in other cognitive conditions.

Human fibrinogen structural scheme

Human Fibrinogen

Although scientists know there is a relationship between blood clots and long COVID, there still needs to be more research done. Even the blood in your body could help research! Research is currently being done on how the SARS-CoV 2 spike protein affects the fibrinogen protein, and research treatments for clot dissolving medications. This is challenging though since the symptoms and diagnosis of long COVID is still difficult to spot. Scientist will continue studying blood samples and patients suffering from long COVID to better understand the sickness.

The research being conducted can be related to the AP Bio class about the role of the immune system is response to the virus. The immune system is very responsive when COVID is introduced to the body and when it is gone in long COVID patients. A study was conducted and it was found that participants with long COVID had higher levels of non-conventional monocytes and activated B lymphocytes. They had lower levels of type 1 conventional dendritic cells and central memory T cells. The B cells are responsible for attacking pathogens that are free floating, and T cells are responsible for attacking pathogens in infected cells. The dendritic cells break down pathogens and present the antigen on its surface for it to then be found by the T helper cells to pass on the information. These participants’ antibody responses is also stronger against the SARS-CoV-2 spike protein. Those who do not have long COVID do not have responses as strong. Long COVID participants also are more susceptible to other diseases. Other disease, once in the body can trigger the body to have more and worse symptoms. All these specific parts of are immune system all work together in all of our bodies to form the way we each combat infections. We should all be grateful for processes our bodies go through to help us get through our everyday lives.

Aftermath Mysteries of COVID-19

Greetings, health explorers! Today, we’re diving into the twists and turns of a new study that unveils what happens in the aftermath of COVID-19. To put this into context, let’s picture this: you have now gotten rid of COVID from your body after suffering for a few days, but the health challenges still linger. A fresh study with 140,000 US veterans reveals how risks, from diabetes to fatigue, can play the long game for at least 2 YEARS! Crazy right? 

The research revealed that patients initially hospitalized during their COVID-19 cases were more likely to experience these health problems. However, even those with milder initial infections were still at a higher risk for about one-third of the analyzed medical issues compared to those who didn’t test positive. The most common problems align with long COVID symptoms such as fatigue, memory problems, loss of smell, blood clots, metabolic issues, and gastrointestinal problems. The study found that for every 1,000 people infected with the coronavirus, a cumulative 150 years of healthy life is lost due to persistent symptoms, highlighting the significant impact of long COVID. 

The article notes limitations. Some of these limitations include relying on electronic health records and potential skewing due to the predominantly male and older veteran population analyzed. It also did not include individuals who may have been infected but did not receive a positive test result in the early stages of the pandemic when testing was limited.

Wow, the impact of COVID-19 on long-term health is truly eye-opening! What are your thoughts on how we, as a society, can better address and manage the challenges posed by Long COVID? Share your insights below!

To set the stage, the World Health Organization (WHO) defines Long COVID, also known as Post-COVID Conditions, as the persistence or development of new symptoms three months post-initial SARS-CoV-2 infection, lasting at least two months with no other explanation. The Centers for Disease Control and Prevention (CDC) expand on this, noting that Long COVID encompasses a large variety of health issues affecting various body systems, even emerging after mild cases or in those who never tested positive for COVID.

Delving into the ideas, Dr. Akiko Iwasaki of the Yale School of Medicine and director of the Yale Center of Infection & Immunity, underscores that Long COVID is NOT A singular disease. Her research puts forward 4 hypotheses, suggesting that persistent virus remnants, autoimmunity triggered by B and T cells, reactivation of dormant viruses, and chronic changes post-inflammatory response may all contribute. SARS-CoV-2 without background

In AP Biology, we learned about the immune system and B and T cells. The immune system plays a crucial role in identifying and eliminating pathogens, but in some cases, remnants of the virus may persist. This situation involves the adaptive immune response, where B and T cells are responsible for recognizing and responding to specific pathogens. Autoimmunity is triggered by B and T cells. The immune system is designed to recognize and target foreign invaders. Sometimes, it can mistakenly attack the body’s own health cells, leading to autoimmune disorders. B and T cells are crucial to the adaptive immune response. 

How have your studies or interests in biology influenced your understanding of topics like the immune system and the function of B and T cells? Share your insights! Fimmu-11-579250-g003

Some statistics addressed in the Yale Medicine article, address the question of Long COVID’s trajectory, the Household Pulse Survey in the U.S. shows a potential decline, with reported symptoms dropping from 19% in June 2022 to 11% in January 2023. The true prevalence remains elusive, with estimates suggesting 65 million affected globally, potentially underreported due to the rise in at-home testing since 2022. 

Now, let’s connect this to the study involving 140,000 US veterans. The article  showcases the persistent health risks associated with COVID-19, unveiling that even individuals with milder initial infections face a higher risk of enduring medical issues. Some problems at the top of this list include: fatigue, memory problems, loss of smell, blood clots, metabolic issues, and gastrointestinal problems.  

For every 1,000 people infected, the cumulative loss of healthy life due to persistent symptoms amounts to a staggering 150 years. While the study acknowledges limitations, like reliance on electronic health records and potential population skew, it underscores the importance of protecting ourselves from COVID-19, given its potential long-term health consequences, even from seemingly mild infections. 

Long COVID demands continued attention, research, and comprehensive strategies for prevention and management. As we reflect on these findings, it is evident that understanding and addressing Long COVID is crucial.

What are your thoughts on this?

Shifting gears, another article from The Centers for Disease Control and Prevention (CDC)  delves into new guidance for healthcare providers treating patients with post-COVID conditions. The term “long COVID” is introduced, emphasizing that these conditions can affect individuals regardless of their initial symptoms. The CDC highlights a broad spectrum of symptoms, including heart palpitations, cognitive impairment, insomnia, and post-exertional malaise (PEM). While primary care providers can manage many cases, the CDC warns against relying solely on diagnostic results. People with post-COVID conditions are advised to continue preventive measures, and COVID-19 vaccines are highly recommended. The guidance is subject to updates as more information becomes available.

The FAIR Health study mentioned in the CDC article, indicates that over 23% of COVID-19 patients experience post-COVID conditions, with pain, breathing difficulties, hyperlipidemia, malaise, and fatigue being common. Half of hospitalized patients developed post-COVID conditions, and there’s a higher risk of mortality following severe treatment, more so for hospitalized individuals. The American Academy of Physical Medicine and Rehabilitation admires the CDC’s guidance for improving healthcare responses for long COVID.

As I did my research surrounding a health challenge that stretches far beyond the initial impact of the pandemic, the significance hits close to home. It’s not just data; it’s the lived experiences of individuals moving through the long-lasting effects of COVID-19. This isn’t just a call to action; it’s a call for our collective attention, research efforts, and a compassionate response. This health issue isn’t confined to statistics; it touches the lives of millions worldwide, making it a cause that resonates deeply within us all.

Powered by WordPress & Theme by Anders Norén

Skip to toolbar