Viruses have been getting a lot of publicity recently with the rise of COVID-19 and its subsequent variants. But what actually is a virus? And how do viruses differ from other forms of pathogens? Recently, the rise of flu season has led to further questions about the differences between COVID-19 and influenza and how they can overlap. The term virus is broad and dynamic, encompassing a wide variety of pathogenic microorganisms that replicate inside living cells. Pretty much every type of living organism is a victim of viral infection to some extent. And viruses have left an indelible mark on…
Comments closedTag: SARS-CoV-2
Over the past couple of months, the resurgence of Covid-19 cases has been disappointing, to say the least. Just as we were gaining ground in the battle against this virus, it launched a brutal counterattack—the Delta variant. Covid-19 isn’t the first virus to employ this sort of adaptable retaliation survival strategy. In fact, quick mutation and evolution is a viral mainstay—one that enabled viruses to persist and become the most prevalent “organism” on Earth. But how does something that is essentially just some DNA wrapped in a protein shell evolve and change its strategy quickly enough to throw even 21st…
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The last few weeks, we’ve been discussing some of the complicated history and science surrounding vaccination and immunity. The strategic and targeted defensive strategies employed by the immune system are by no means perfectly impregnable, but they represent several millennia of evolution under fire. Pathogens have always had a leg up on multicellular organisms—evolving more quickly and chaotically, unburdened by the constraints of form and function. They aren’t very sophisticated, but in terms of sheer brute force, there are already more viruses on earth than there are stars in the entire universe. We are besieged on all sides by these…
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CRISPR-Cas9 has made genetic engineering easier, faster, and cheaper than ever before. A scientist interested in manipulating a particular gene only needs to search the gene’s sequence for a suitable PAM. Once a PAM is found, the corresponding Cas9 can be ordered or harvested from its bacterial strain (and as I mentioned last week, even if a PAM isn’t found, it is possible to engineer a Cas9 to recognize a new PAM sequence). An appropriate sgRNA (the crRNA:tracrRNA fusion molecule) can be designed by identifying the target sequence 20 nucleotides upstream of the chosen PAM. These sgRNA’s can be engineered…
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A few weeks ago, we talked about antibodies and how they can convey immunity after an infection or a vaccine. Recently, there has been a lot of talk about antibody tests and whether they could be used to allow “immune” individuals to return to work. But there are a lot of misconceptions about these tests, what they actually tell us, and how they should be implemented. There is a persistent misconception that if an individual has antibodies, they are completely immune to reinfection. It is completely possible, even likely, that if you got the coronavirus and barely had any symptoms,…
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Last week, I very briefly brought up the concept of a “cytokine storm,” a dangerous immune response to a perceived threat. Cytokine storms have been linked to Covid-19 related deaths—where, in some cases, patients weather the disease itself for some time only to suddenly crash. Cytokines could even possibly be the culprit behind the blood clots and strokes that are being seen in some Covid-19 patients (although this has not been confirmed—the prevalence of blood clots in Covid-19 patients may be a direct consequence of the virus). Cytokine storms are immune system overreactions that can happen towards the end of…
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The last couple weeks we have discussed the importance of vaccines and anti-viral drugs—our arsenal of weapons against viral infection. This week, I want to zoom in a bit and specifically investigate what researchers are doing to develop tools to fight Covid-19. Currently, most people who are able to do so are staying home, in order to curb the spread of Covid-19. A vaccine, if it can get past clinical trials and be distributed to the general public, could allow for enough herd immunity for us to return to normalcy. But it takes a long time to verify that a…
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Last week, we discussed the immune system and vaccines—our armor and shield against viral invasion. But what happens when those defenses aren’t enough? As our immune system begins taking arms against an enemy horde, we must pivot from girding our defenses to looking for ways we can help our immune system achieve victory quickly with minimal cellular casualties. Just like Gandalf bringing the Riders of Rohan to aid at the battle of Helms Deep moments before the heroes’ glorious defeat (yes, I did use this metaphor to make a LOTR reference), anti-viral drugs can mean the difference between victory and…
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Last week, we went through some of the science of viruses: how they infect, how they evolve, and how they can make the jump from one species to another. This week, I want to touch on some of the ways the medical field combats viruses, such as with vaccines, used to promote immunity, and anti-viral drugs, used to treat viral infections and reduce their severity. In the past few months, researchers around the world have been scrambling to produce a vaccine or anti-viral treatment to curb the spread and mortality rate of Covid-19, producing results at record breaking speeds. But…
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I’ve seen a ton of posts online comparing Covid-19 to H1N1 and claiming that the media has over-hyped this pandemic. Certainly, the media has been known to blow things out of proportion. Are quarantining and social distancing “over-reactions”? While it may be tempting to compare the two pandemics on surface level statistics like death counts or case numbers, it is important to realize the ways in which they are not comparable. One of the most obvious differences is in their transmissibility. Last week, I threw out some numbers comparing the transmissibility of Covid-19 to that of the flu; every person…
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