Corona-zona

A recent article in the New York Times details problems one pharma company is having getting approval for a new post-infection COVID-19 treatment. This post is your TL;DR for that article. Existing monoclonal antibody treatments have lost effectiveness due to new variants, and the only option for universal treatment at this point is Paxlovid. However, Paxlovid has worrisome interactions with other drugs, meaning some people can't take it. A company called Eiger Biopharmaceuticals developed and requested emergency use authorization from the FDA for a drug called  pegylated interferon lambda. Interferons are proteins that signal to your immune system that there is an invader that needs to be eliminated.   Interferon drugs are tricky because they signal your immune system to attack, and most kinds have receptors throughout the body. However, the company found a type of interferon whose receptors are specific to the respiratory tract. This means the drug could be usefu...

I have yet to be infected with SARS-CoV-2—as far as I know, at least not to the point that I became ill. I am knocking on wood as I write this.  Why have I not become infected? I know lots of other people who are not COVIDiots and take precautions. They are fully vaccinated and boosted (as am I). Still they've gotten infected, some of them more than once.  What is going on with us " NOVIDS ," then? Scientists are wondering this too, and over the past week this has been the subject of several articles I've run across.  This one says scientists are starting to close in on some explanations for why an estimated 30% of people in this country have never gotten COVID-19. One possibility is lucky genetic breaks. A study a couple of years ago identified a whole slew of genetic markers associated with people who've not become ill with COVID-19. Many of these are associated with "up-regulation of cholesterol biosynthesis" and "sequestration of ACE2 receptor...

  As you probably know, SARS-CoV-2 has a wide range of severity levels. Some never get it despite exposure and lack of vaccination. Some people get asymptomatic cases, some get mild cases, and some get quite severe cases. Scientists are trying to work out explanations for these things. Two recent stories summarize this work. First, there is work on the never-COVID people.  This NPR story talks about research exploring two reasons why some people never get the virus even though they are chronically exposed. One study showed that exposure to other coronaviruses—the kinds that can cause common colds—might prime the immune system to fend-off SARS-CoV-2. It looked at the blood of about 60 health care workers at a hospital who were repeatedly exposed to the virus (before vaccines were available) but never fell ill. Analysis of their blood showed the presence of an immune cell called a cross-reactive t-cell. Workers who did become ill did not have these cells. Since SARS-CoV-2 is a...

Walter Reed Army Institute of Research  People who study the evolution of viruses published an op-ed in yesterday's New York Times about the likely future evolution of SARS-CoV-2. Here are some high-points of the essay. First, viruses evolve to survive and reproduce better. That is just what they do. There is no reason to think SARS-CoV-2 will stop evolving. Second, there are still plenty of pathways available for further evolution. The writers reckon there are "nearly 2000 other ways the 201 targeted amino acids could could mutate and still be able to attach to human cells." Third, the evolutionary pressure on the virus is to become better at spreading. It can do this by becoming more contagious and/or better at evading the immune system. They say it is "remarkable" how good this virus has been at responding to that pressure. Fourth, how much more transmissible the virus could become is unknown. There is not an infinite capacity: "a cheetah can’t evolve t...

For some time we have known that obesity elevates the risk of having a serious case COVID-19. The CDC says  "the risk of severe COVID-19 illness increases sharply with elevated BMI" (body mass index). New research, published in pre-print  (meaning it has not yet been reviewed), sheds light on why that is true: The virus attacks fat cells. This, in turn causes an inflammatory response. The more fat you have the bigger the response and the more severe disease you're likely to have. The relationship between fat and inflammation has been on scientists' radar for some time. They believe chronic low-grade inflammation caused by fat is responsible for the negative health outcomes associated with obesity, like heart disease, cancer, diabetes, and so on. The coronavirus seems to turbocharge this process. Scientists think  this ability to infect fat cells may also help the virus evade our immune response. In other words, fat may serve as something of a reservoir where the viru...

  As if our friends in India aren't having enough problems with the COVID-19 wave there, there is a new problem. This one isn't a complication of the disease per se but a result of its treatment. India is seeing a huge spike in cases of mucormycosis, a.k.a Black Fungus, in humans. According to a  report , India has had a handful of cases over the last decade, but is suddenly seeing tens of thousands of infections. Experts think this is happening because shortages of oxygen are causing physicians to prescribe more corticosteroids to people with COVID-19 (you can also buy these drugs without a prescription in India). Experts reason that these drugs are suppressing inflammatory responses and are thereby creating opportunities for the fungus to take hold. The disease happens when people inhale spores of a mold that lives in the ground and decaying organic material. According to the CDC , infections can happen in the lungs and gastrointestinal tract, but the infections being ...

  Today, a few notes on research I have run across about all the ways SARS-CoV-2 messes with your body. Spiking Your Lungs A lot of people assume the virus has to get into your cells and start replicating to do it's thing. Not necessarily true.    According to a recent study the "spike" proteins on the virus surface do damage all by themselves, whether or not the viral material enters your cell. Effects include severe lung inflammation.   The researcher said in an interview that “Our mouse model dramatically reduces the danger of doing this type of research by allowing COVID-19 lung injury to be studied without using the intact, live virus. This will greatly increase and diversify the ability to do COVID-19 research. Our model will also likely be useful for studying other coronaviruses.” Checking Your Gut's Immune Response To study how the virus affects your gut, scientists built 3-dimensional tissue cultures derived from actual human gut cells. They expos...

  It has always puzzled me how one can be infected with SARS-CoV-2 and not show any symptoms. After all, the bug has invaded you and has hijacked your cells to make copies of itself, rather than doing what they're supposed to be doing. How can that be? A new study just published in Nature Medicine sheds some light on the matter.  The authors claim it is the first study to compare the immune responses of people who have no symptoms to the immune responses of people with a more serious infection. The actual study is full of big words that are probably only meaningful to an immunologist. Fortunately a helpful science reporter has dumbed it down to the point where I can understand it.   Essentially, people who have asymptomatic infections have high levels of B cells (a type of white blood cell) in their noses and other mucous passages. These cells detect pathogens and help initiate an immune response. These cells were missing in people with more serious infections. P...

Today, just a quick post to recommend this excellent essay in The Atlantic.  It's officially about asymptomatic infections. But in the course of covering that it goes into great detail about how the immune system works and responds to viruses. Regarding asymptomatic infection, it seems that some viruses in some people are able to suppress the innate immune reaction. That's an initial, generalized immune response to invaders, meant to keep them in check while your adaptive immune response kicks into gear to attack the specific virus (or whatever pathogen).   The innate response is what makes you feel sick. So, if it is suppressed you can be infected and spread the virus without knowing it.  I still don't get how lots of your cells could be hijacked, making virus copies rather than doing what they're designed to do, and not feel some effect of this. But like the article says, much of this is still mysterious. Image by  Bruno /Germany  from  Pixabay ...