Coronamonomania Lasts Forever, Part 238

There have been four commonly circulating human coronaviruses.  I think it is pretty clear that CV-19 will be the fifth.  And it is likely the other four started the same way–a serious epidemic followed by general circulation in a mostly mild manner.  The most recent of the original four is called OC 43 and is similar to CV-19.  It may have been the agent for a serious epidemic in Europe and Russia at the end of the 1800s.  This story in Science details the history of significant human coronaviruses.  (Science Article)

Superspreaders and superspreading appear to be a real phenomenon.  Some people just have higher viral loads and spew out more virus.  This study was a meta-analysis of research looking at the phenomenon.  It appears that those who are symptomatic, aged 49 to 64, and have a lot of contacts are more likely to infect large numbers of people.  Households and other settings with lots of people in close proximity also facilitate mass infections.  All just a matter of common sense.  The more interesting thing is why some people are prone to having high viral loads.  (Medrxiv Paper)

On the other hand, there are people who appear to be very hard for the virus to seriously infect.  Often referred to a asymptomatic infections, in these cases, virus is present in the respiratory tract and may have some replication, but is quickly cleared.  This clearance appears to be due to a very rapid innate immune response and T cell reaction, and has little involvement from B cells and resulting antibodies.  This means the people often have low antibody levels and may be missed in seroprevalence surveys.  (Nature Article)

A study from the Netherlands examines the antibody-producing effects of vaccination and infection.  The more immune response-provoking events, the higher the antibody production.  Production was also associated with more serious illness.  (Medrxiv Paper)

Concerns have been expressed about whether some batches of CV-19 vaccine were “defective” in some manner and more prone to causing adverse events.  This study from Denmark compared the batches of vaccine used in the country and found no difference across batches for adverse event rates.  (Medrxiv Paper)

Here’s a study I herd of that is a lot of bull and I am not in the mooed to be cowed into not covering it.  It looks at whether a common coronavirus infecting cattle and some humans might have cross-reactivity with CV-19.  It appears that it could.  So go hang out with the cows if you want to be protected.  (Medrxiv Paper)