In this paper the authors surveyed over 6000 health care workers in Los Angeles County for infection or prevalence of antibodies. (Medrxiv Paper) Four percent were positive, with most being asymptomatic and unaware they had been infected. The most commonly reported symptom was loss of sense of smell, which is turning out to be a significant differential diagnosis factor for CV.
More T cell research here. (Medrxiv Paper) The authors did an in-depth profiling of T cell responses by 3 acutely infected patients and 58 recovered ones, as well as a broader screening across over 800 recovered patients and 3500 uninfected persons. The authors used a unique assay that they created, which could more quickly and accurately detect T cell responses. As have other studies they found a robust T cell response to coronavirus infection, both helper T cells and killer T cells. A large number of killer T cell variations were directed against just a few virus regions. T cells are a central component of the immune response to acute infection and of protection against reinfection. Prior research on other strains of coronavirus has shown that T cell memory and response lasts for years or decades, even when antibody responses cannot be detected. This paper continues the trend of finding a sustained and lasting T cell response to coronavirus infection and a strong likelihood of cross-reactive T cell responses.
What would a day be without some research relating to transmission. (Medrxiv Paper) This study comes from Florida and looks at the presence of virus in hospital rooms. The researchers used air sampling units placed in patient rooms used exclusively for CV patients and they tested the virus recovered for viability. The found virus in the samples and said that “suggested” aerosol transmission. The virus was cultured and was viable. But the amount collected was small, and it wasn’t clear it would represent an infectious dose. Still, given how the virus seems to spread easily in some circumstances, I am leaning toward frequent aerosol transmission.
People in Sweden have begun pushing back against the extremely misleading coverage of the epidemic in that country, including via this comment in the British Medical Journal. (BMJ Article)
You may recall I have mentioned before the 1957-58 flu, which was much worse than coronavirus, and the more stoic response to it, which avoided serious disruption to normal life and damage to the population’s health. This article summarizes some information about that flu and response. (Flu Story)