June 15, 2020
COVID 19 continues to dominate the airwaves of medicine and Dr. Peter Attia just posted some excellent information worthy of your time.
Part 1) It appears that we may have a large subset of our population walking around with potentially protective cross reactive antibodies to SARS2 from other beta cotronaviral infections that we call the common cold.
Directly from the Cell paper: "Regarding the value of cross-reactive T cells, influenza (flu) immunology in relationship to pandemics may be instructive. In the context of the 2009 H1N1 influenza pandemic, preexisting T cell immunity existed in the adult population, which focused on the more conserved internal influenza viral proteins (Greenbaum et al., 2009). The presence of cross-reactive T cells was found to correlate with less severe disease (Sridhar et al., 2013; Wilkinson et al., 2012). The frequent availability of cross-reactive memory T cell responses might have been one factor contributing to the lesser severity of the H1N1 flu pandemic (Hancock et al., 2009). Cross-reactive immunity to influenza strains has been modeled to be a critical influencer of susceptibility to newly emerging, potentially pandemic, influenza strains (Gostic et al., 2016). Given the severity of the ongoing COVID- 19 pandemic, it has been modeled that any degree of cross-pro- tective coronavirus immunity in the population could have a very substantial impact on the overall course of the pandemic, and the dynamics of the epidemiology for years to come (Kissler et al., 2020). A key step in developing that understanding is to examine antigen-specific CD4+ and CD8+T cells in COVID-19 cases and in unexposed healthy controls, utilizing the exact same antigens and series of experimental techniques. CD4+ T cell responses were detected in 40%-60% of unexposed individuals."
(Grifoni et. al. 2020)
What this means for the rest of us is as follows. If you have had significant exposure to beta coronaviral upper respiratory infections over time, you may have cross reactive immunity that can significantly reduce your risk of a bad outcome.
Part 2) Increased psychological stress puts one at higher risk for a negative outcome when exposed to a viral illness.
From Dr. Attia's blog: "Can psychological stress-when psychological distress exceeds a person's ability to cope-suppress resistance to infection? In a classic New England Journal of Medicine paper from 1991, Sheldon Cohen and two of his colleagues tried to answer this question by conducting the following experiment. Read Dr. Attia's whole discussion on his website below. For all 394 subjects exposed to a virus, the incidence of clinical colds (i.e., symptomatic infections) ranged from approximately 27 to 47 percent, and overall infection rates from 74 to 90 percent, according to levels of stress. In short, higher levels of stress were highly associated with more infections, overall, and more symptomatic infections (colds)."
He goes on to write: "What's also interesting from this experiment is that the effects of stress were the same, directionally, for both subjects who were seropositive and seronegative (i.e., those who did and did not have pre-existing antibodies to the virus, respectively) before being challenged with a virus. While those who were seropositive had lower absolute rates of infection (as expected), the relative trends were similar to those who were seronegative. In other words, even if subjects were previously exposed to the virus, and had specific antibodies against the virus, the incidence of infections and symptomatic infections were positively associated with increased stress." (Attia newsletter 2020)
My take from the two discussions: We have known for a long time that chronic stress wrecks everything from hormonal function to immunity to general wellbeing. Thus, it is not surprising to see these results play out in a study. What we need to understand without a shadow of doubt is that we HAVE CONTROL over our risk factors for a negative outcome to any virus or infection for that matter. This is not to say that we will be free of risk if we do everything right, but we will have the best fighting chance against a 120 nanometer killer. A risk free life is impossible, yet we all have the ability to have a significantly risk reduced existence. This is known scientific truth and yet we hear crickets regarding it in the media. Secondarily, we are increasingly likely to have a possibility that cross reactive antibodies exist in those with frequent beta cotronaviral exposure. I think here of teachers, daycare leaders, pediatricians and anyone significantly exposed to children. These highly exposed individuals likely have lowered their COVID risk by choosing an occupation that raises their risk for frequent microbial exposure at baseline.