Coronamonomania Lives Forever, Part 164

How good are antibody tests at detecting a prior infection?  I personally have wondered because in retrospective I thought I likely had an infection very early, in January 2020, and got an antibody test in April of that year which was negative.  This study, while not comprehensive, suggest that the tests are accurate most of the time in people who haven’t been vaccinated, but vaccination cuts accuracy more than in half.  Not exactly sure why that would be.  (JAMA Article)

Why does vaccination lose effectiveness relatively quickly?  Is it largely due to mutations in the virus as it evolves, or does the human immune response just decline over time?  This study finds a fairly significant lessening in just a few months, with a substantial contribution from both changes in CV-19 and a lowering of the immune response due to vaccination.  (Medrxiv Paper)

In a meta-analysis of studies, these authors found that depending on the variant, children and adolescents tend to be both less susceptible to infection and less likely to be infectious than are adults.  (Medrxiv Paper)

And another one of those crappy studies, finding that wastewater surveillance found the presence of new variants up to two weeks before they showed up in the PCR tests.  (JAMA Article)

Kind of an interesting study, would like to see the same for adults.  It compares self-collected swab test results with those collected by a professional in children and adolescents.  With the massive rise in home testing, it is worth knowing how often poor sample collection leads to false results.  98% of the time the results were the same, probably within the error rate of the test itself.  So if children and adolescents collect samples well, I am assuming adults do also.  (JAMA Article)

This study attempts an explanation at why the third dose of a vaccine may have more effectiveness against Omicron variants than just two doses.  The problem with the study, at least in regard to becoming infected, is that the data doesn’t support the notion that a booster dose lessens infection risk for any significant period of time.  But the author’s theory is that compared to a second dose, the third dose prompts responses to less commonly mutated regions of the virus’ genome.  (Medrxiv Paper)

Being infected with more than one strain of CV-19 provides better protection against subsequent infections than does being infected with only one strain.  This makes sense as it likely creates an immune response recognizing more parts of the viral genome.   (Medrxiv Paper)

Early in the epidemic the research on whether smoking increased the likelihood of contracting a CV-19 infection was mixed.  This study looks at vaping and finds that it clearly leads to a heightened risk of getting infected.  (Medrxiv Paper)

Another interesting open question has been whether mixing vaccine types promotes a better immune response. In this study an inactivated vaccine and an mRNA one were compared individually and mixed.  There was essentially no difference in protection.  No dosing strategy did a great job against Omicron.   (Medrxiv Paper)