As you know I am enamored with the discovery that T cells may be the primary response to coronavirus infection. This article gives a pretty easy to understand discussion of the possibility of pre-existing immunity to the current coronavirus strain, in two pages. (Nature Article) The article notes the studies on the issue and that 90% of humans are positive for prior infection by at least three coronaviruses. Pre-existing T cell defenses could be a positive and a negative for upcoming vaccine trials. The presence of T cells could aid in developing a potent vaccine response, but they could also confound attempts to attribute prevention of infection to a vaccine. For influenza, there is an established pattern of beneficial cross-reactivity of T cells. Oh, and here is my favorite comment: ” this could also influence epidemiological modeling and suggests that a sliding scale model of COVID-19 susceptibility may be considered.”
Much of the media, and the New York Times in particular, seem determined to do a hatchet job on Sweden, since it doesn’t fit their narrative that we all need to lockdown forever and be scared sh*tless. A Swedish writer responds to the latest of the garbage from the Times, pointing at the numerous outright falsehoods contained in its most recent hit piece. (Swedish Article) He starts off by stating that Sweden was not trying to protect its economy, it was adopting a strategy that would be sustainable in the long run, resulting in the best health outcomes. In regard to death counts, he points out that Sweden includes every death with coronavirus, regardless of whether it played a role in the death and, although he isn’t quite this blunt, that the US has a number of areas with much higher death rates than Sweden. Swedish life did change substantially, although largely voluntarily, as people reduced activity. He points out serious errors regarding the Times calculation of economic effects, again showing that in fact Sweden suffered much less economic harm than countries with more severe lockdowns. Finally, and this will surprise no one who has watched the complete disintegration of the Times as a source of actual factual journalism, he notes the obvious bias of the Times reporter who wrote the story, as that person had previously, as early as April, sent out tweets calling the Swedish approach “crackpot”.
Here is another detailed paper on the immune response to coronavirus. (Medrxiv Paper) The authors claim to have developed very sensitive assays to identify antibody responses and their neutralizing effects. They looked at 87 infected patients and found such antibodies in all these patients. Antibodies were substantially stronger in hospitalized patients than those treated as outpatients. The strength of the antibodies appeared to wane with time, which would make sense, since the body will not perceive as great a need the further from the time of acute infection. The most important aspect of the study may be that it demonstrates that many current assays simply are not sensitive enough to detect the presence of antibodies.
This article has a more balanced perspective on considering the health impacts of mitigation of spread measures. (JAMA Article) The authors recognizes that consideration must be given to the toll of isolation, depression and job loss. The authors discuss various approaches to weighing the value of lives, and how those lives are affected by the epidemic or actions in response to the epidemic. This is a thoughtful and articulate exposition of the difficult choices around how to respond in our current situation.
Understanding the immune system is a difficult undertaking, due to its considerable complexity. (Nature Article) This article examines how cells other than specific immune cells contribute to the body’s defenses against pathogens. The researchers discovered that structural cells have the ability to help marshal the immune system to respond against an infectious agent. While somewhat jargony, it is worth a read, because you have to appreciate the sophistication of biochemical systems to think about what may be happening when coronavirus meets human (although the underlying study was conducted in mice, raising the age-old question, are you a mouse or a man?).
And, why not end with more bad news about the effects of the lockdown. (JAMA Article) Think the epidemic, or more properly, the response to it, isn’t stressing people and harming their health. You would be very wrong. Over 1914 patients with acute coronary artery disease, some who had a stress cardiomyopathy test during the epidemic and some before, were compared. The incidence jumped four-fold, from 1.5% to 1.8% before to 7.8% during the epidemic. These were all non-CV patients and there are real health consequences. The patients with stress cardiomyopathy end up with longer hospital stays.