By Kevin Roche
That is my advice to myself every day. Take all the cumulative research and data, distill it down to the important points and analyze in a rational and logical manner what it is telling us. Apparently to many of our political leaders the message is “PANICCCCCC!!! RUN AND HIDE IN THE BASEMENT!” The Governors of New Mexico and Oregon have put a “freeze” on their states, which is a cute way of describing the Osterheimlich Maneuver or extreme lockdown. The only thing frozen is their brains. Apparently they have learned nothing from the Spring or Summer and are deep in the acute phase of Coronamonomania. I am waiting for the IB to cave in and do the same thing and I will again give him a lot of credit if he rightly resists that temptation and again becomes The Governor.
This is a recapitulation of much of the basics that I have presented before. This strain of coronavirus is clearly more dangerous and lethal than the typical seasonal coronavirus strains, and follows the pattern over the last 20 years of coronavirus strains tending to emerge that are more dangerous. This version may be more infectious because it has a different, more common cell receptor, it has a stronger receptor binding capacity and it may have an enhanced ability to down-regulate the immune system. I believe that the evidence strongly suggests it can survive and drift in smaller aerosolized particles in the right conditions and that this ability accounts for the difficulty in suppressing transmission. At an individual level, upon exposure, actual meaningful infection appears to be dependent on a large variety of factors, including viral dose (the number of virus particles or virions) and the health status of the exposed individual, particularly their immune status. People appear to be capable of transmitting while asymptomatic or presymptomatic, although such persons may have lower viral loads and other characteristics (e.g., not coughing) that lessen the likelihood that they will actually infect another person.
From an epidemiologic or population perspective, what matters most is understanding these transmission dynamics, understanding population susceptibility and assessing the effectiveness of potential measures that might be taken to control spread. Obviously, understanding the danger posed by the pathogen is also critical knowledge in determining what mitigation measures, if any, might be appropriate. CV-19 is an interesting pathogen, the most studied in history, exceeding even the HIV virus. It is not that lethal, for which we should be grateful and has an incredible severity gradient across age. For the general working age population without certain serious pre-existing health conditions, like true obesity, it is a threat, but no more so than many other potential harms. For children and young adults, serious illness is very rare. For the frail elderly, it is often deadly, although even among this population large percentages of asymptomatic infections can be found. Primary features from an epidemiologic perspective would include this extreme bifurcation of illness by age, potential front-loading of severe illness with the most vulnerable being affected first, and apparent high transmissibility or infectiousness in some settings. Another facet of the epidemic that should be very apparent now is a geographical, seasonal pattern that creates a far more hospitable environment for the virus and transmission under certain circumstances. The Upper Midwest and Rocky Mountain states and Europe appear to be particularly favorable to transmission at this time. It is also intriguing that much of Asia appears to have more limited transmission, although in some countries, such as China, opaque data makes accurate assessment of spread or prevalence difficult. While mitigation strategies may be responsible for this difference, I believe it is equally likely that general health status, particularly much lower prevalence of obesity, and greater pre-existing immune response capability are responsible. It would be extremely helpful to separate the health and biological aspects of the apparent differential spread in Asia from the response ones.
An epidemic slows when the virus finds fewer targets that can be infected. It does not appear that even at the start of the CV-19 epidemic all persons were equally susceptible to either being infected or being infectious. This is likely largely due to variation in immune system status, and in particular, there may be significant number of people with either general immune responses to pathogens or specific adaptive immune responses stemming from prior seasonal coronavirus infections. If so, and a substantial body of research supports this possibility, these persons upon exposure likely clear the virus before becoming infectious. People who have a CV-19 infection develop a strong and durable adaptive immune response, with very rare exceptions. This response may be dominated by the T cell arm of adaptive immunity, but strong B cell and antibody responses are also present. A vaccine would futher facilitate adaptive immunity and slow transmission.
A substantial portion of the US population has likely been infected and/or has reduced susceptibility to infection, particularly in more densely populated areas. Even in this new case surge, it appears that more densely populated metropolitan areas are seeing slowing slower case growth than areas which likely did not experience high infection rates in the spring. Along with geographical seasonal factors, population density, age structure of the population and general health status of a population appear to be key factors associated with total burden of CV-19 illness. The past pattern, likely driven by both virus infectiousness and behavioral factors, is for relatively short, sharp cases surges. This would suggest that classic notions of percent of population infected for significant slowing of transmission are far too simplistic to understand actual epidemic courses. More sophisticated modeling which accurately replicates heterogeneity in contact patterns, susceptibility to infection and infectiousness seem to produce more accurate depictions of likely epidemic course.
This section is more opinion, but I believe research and data support my assertions. Our response to this epidemic has been unprecedented and unbalanced. It has ignored all the consequences of mitigation or suppression tactics and focussed only on reducing cases and illness burden from CV-19. In doing so, enormous economic, health, social and educational damage has been inflicted on the population. This cannot be disputed. This damage is directly attributable to our decision about how to respond to the epidemic not to CV-19 disease itself. Evasion of responsibility for this damage is not helpful or transparent for the general public, who should be given full data on the consequences of actions so that at least in democracies they can express their opinions on the propriety of those actions.
We have also exaggerated the seriousness of the epidemic by testing and reporting disease and death in an unprecedented manner. Mass media and politicians have engaged in hysteria, mass delusion, and terrorization of the population. Political leaders have been unwilling to acknowledge the ineffectiveness and likely futility of most mitigation tactics. Lockdowns, stay-at-home, closing schools, massive testing and supposed contact tracing, mask wearing, etc. clearly don’t have much of an impact. Honestly, we need to accept that short of truly extreme lockdowns, literally telling people they cannot come out of their houses, it is difficult to slow transmission. And you can’t lockdown forever, the virus isn’t magically going away, when you lighten up, cases will just start up again. And why would you lock down so extremely when the burden of illness on the general population is simply not very high.
So resist the renewed hysteria and panic, do what you can to keep yourself and others safe, recognize that extreme suppression measures have a cost that isn’t justified by the benefit and do your best to be patient and wait this out. It may roll over more quickly than we realize.