A Head Full of Coronavirus Research, Part 50

I really am tired of the mask stuff, but it has become such a politicized emblem that now we get all kinds of bogus research to show that they do or don’t work.  If you want to see a couple of articles which purport to identify risks of wearing masks, and which have been suppressed at several websites, here is a link.  I have seen a lot of the underlying material before and it is well written, but I am as skeptical of some of the conclusions from correlation studies saying they don’t work as that they do.  I just don’t think those are high-quality data.  I do think it is pretty clear at a macro level that masks don’t prevent widespread transmission.  They couldn’t when you compare rates of mask-wearing to case levels in various locations.  But these articles are a good compilation of anti-mask research.  (PDMJ Article)  (PDMJ Article2)

Now here is another of these studies purporting to show that a mask mandate was associated with lower cases, this time in the St. Louis metro area.  (Medrxiv Paper)  I also tire of making the same points about these studies.  A mask mandate doesn’t tell you anything about mask wearing rates.  It is about impossible to separate out the effects of mask wearing from other mitigation efforts or the behavioral choices of citizens or trends already in place without regard to mask mandates or mask wearing.  This brief paper is particularly pathetic for not even attempting to address these issues.

Interesting antibody survey among children in a region of Germany.  (Cell Article)   While prevalence was not high, around 1% to 2%, it was six times greater than detected cases among children.  47% of all cases were asymptomatic.

Now on to some harder science.  One aspect of this epidemic that should be obvious is the general threat to human health posed by coronavirus evolution.  As with flu vaccines, if we are going to be protected against coronvirus, it would be advantageous to have a vaccine that has the potential to defend against most coronaviruses, present and new.  The researchers here sought to identify common genetic fragments across human and animal coronaviruses, to inform vaccine development.    (SSRN Paper)    Among other findings, they identified cross-reactive fragments that prompted immune responses from non-CV-19 infected persons.  These cross-reactive responses occurred among both helper and killer T cells, as well as B cells.  They further identified that while some immune cell populations did not appear to differ by severity of disease or among non-CV-19 infected persons, certain populations of helper T cells appeared to be larger in asymptomatic patients and in the non-infected group.

And this paper is related in that it also examines fragments which prompt an immune response and possible cross-reactivities with seasonal coronaviruses.  (Medrxiv Paper)   Blood from CV-19 patients and unexposed persons was tested for antibody presence.  Spike and nucleocapsid fragments tended to dominate in prompting an immune response.  Persons with CV-19 had antibody responses cross-reactive with seasonal coronavirus and some uninfected persons showed cross-reactivity to CV-19.

And this paper discusses the evolution of coronaviruses, a topic of relevance since they seem to have developed a recent fondness for crossing over to humans.  (Medrxiv Paper)   In examining the genomes of seasonal coronavirus, the researchers detected changes, particularly in the spike proteins, that might facilitate evasion of existing human immune defenses.  If so, people would probably need regular vaccines to protect against mutations in the viruses from year-to-year, just as we do with the flu.  The evolutionary study also suggests that coronaviruses are likely to continue to evolve to get better at infecting humans.

Finally, for those of you who wipe your groceries down with anti-infectives, this study looked longitudinally at the presence of virus on common surfaces.  (Medrxiv Paper)   Surfaces included door handles to businesses, trash can handles, crosswalk buttons, etc.  Less than 10% of the samples were positive and I would bet that they were almost all fragments versus viable virus.  The authors estimated a very low risk of transmission.  There was a correlation between positive samples and case trends a week later.  In general, pretty clear that while virus fragments may be found on surfaces, they aren’t responsible for much transmission.