A Head Full of Coronavirus Research, Part 82

A local reporter, Tom Hauser put together a little chart on the vaccination progress of Minnesota, our neighbors and a couple of other states.  Note that Minnesota thinks it is very sophisticated among states and a beacon of good government, not to mention having the best CV-19 data and response in the world.  Yet somehow we have a fraction of the vaccinations of our much smaller neighbors, North and South Dakota, who must have a much harder time distributing the vaccine in a thinly-populated state.  On a per capita basis, we, well, suck.  I do not jest when I say that the current administration has been completely incompetent in almost every respect in regard to handling of the epidemic.

My other observation for Minnesotans, aren’t you terrified by how our cases just keep growing and growing and we are just facing this incredibly horrible winter of never-ending infections until we all can get vaccinated.  Oh, wait, as it seems to always do, CV-19 surged on its own timeline and receded on its own timeline.  Cases continue to drop rapidly here and at some point we will hit a background rate that is pretty low and then we should declare victory and stop the coronamonomania.

This study in JAMA reports on the improvement in hospitalization outcomes, particularly lower mortality.  (JAMA Article)   The researchers tracked outcomes in about 950 hospitals through June 30.  (Be useful to extend that to now.)  Most hospitals showed a significant improvement in mortality rates.  At the same time there was extensive variation across hospitals, but much of that appears related to patient characteristics.

Another paper reflecting long-lived antibody persistence, regardless of disease severity.  (Medrxiv Paper)   The study was done in Austria among about 1650 adults.  It tracked prevalence at 3 and 6 months periods.  About 10% were initially positive.  Those persons who were positive, remained positive at 6 months.  Neutralizing antibodies to the receptor binding domain showed the greatest persistence.  And those antibodies were present even in those with mild illnesses.

This study tracked antibody prevalence among a population in the state of Wisconsin from spring through late fall.  (Medrxiv Paper)   Adjusted prevalence rose from 1.6% in the spring wave of tests to 6.8% in the fall wave.  Still seems low to me and hard to know how accurate the assays used are.  Milwaukee had a rate of around 10%, but other areas of the state also showed substantial prevalence and prevalence growth, including more rural areas.

Another prevalence study, this one among Swiss school children.  (Medrxiv Paper)   2603 children were antibody tested in June and July, with a prevalence of 2.4%; 2552 were tested in October and November with a prevalence of 4.5%.  Schools remained open during this time, when there was high community transmission.  There were few outbreaks of even 2 or 3 cases in a school and no school-wide outbreaks.

How about prevalence among Swedish home care workers delivering services to the elderly?  (Medrxiv Paper)   Five companies and about 400 employees were included in the study, done in the spring.  About 20% of the workers were antibody positive, compared to around 10% of a reference population.  About 3.5% were currently positive by PCR test.  This suggests that this group of workers is at risk for infection, but no information was provided about how often they may have passed infection to clients or how often they may have contracted infection from clients.

If you want to read about modeling on how the virus goes from an infection in the upper respiratory tract to the lungs, this is the study for you.  (Medrxiv Paper)

And if you like to read about population immunity and when it may occur, kind of an interesting paper.  (Medrxiv Paper)  The author suggests that the virus basically will kill about 2500 per million of population and that when around 2000 per million have died, there have been enough cases to create population immunity.  While I might agree that deaths can be an accurate indicator of overall case levels, differences in how deaths are attributed to CV-19, in population age structures and health status and in medical resources can affect the level of deaths.  The author suggests that places like New York and New Jersey have limited remaining susceptible populations.  Either that or they are exceptionally good at killing old people and will be well above that 2500 per million limit.