This is a great interview with epidemiologists from England. (Interview) I strongly encourage you to watch it. Lot of common sense approaches to the issues. They again say attempts at suppression are pointless. The lockdowns cost more than they benefit. There is no solid evidence to support the value of masks. And so on.
No day is complete without some mask stuff. People who don’t like them tend to slant the research one way and people who think we should all wear them while we sleep and even after we are dead slant it another way. This article is slanted toward the don’t like group, but compiles information on the research etc. (Mask Article) As I keep saying, wear them if you want to, don’t think they are keeping you from getting infected or infecting others, especially if they are cloth, be aware that there could be health issues related to use and because of all that, don’t go for the nonsense around mask mandates.
And of course, we also have to have another contribution to the aerosol spread debate, but this one has a mask twist too. (Medrxiv Paper) The researchers sought to ascertain if masks would stop aerosols of the size likely to be containing coronavirus. The authors are from the pollution engineering department at a University in Greece. They tested cloth and other masks against various sized particles. Mask efficacy depends on material, design, fit and airflow around the mask and in and out of it. Eight commercially available face masks were tested against aerosols in the likely range of coronavirus particles. Five were three layer masks, one was a supposed N95 mask with a valve and two were fabric. The masks were tested by fitting to equipment that simulated breathing, in an indoor environment. The cloth masks were basically worthless. Only the N95 type mask showed any high level of efficiency in removing particles in the typical size of coronavirus aerosols. The authors further noted that fitting and improper wearing issues would lessen the effectiveness of the masks compared to that seen in the experiment. So again, if there is substantial aerolization of the virus, masks shouldn’t be relied on as absolute protection.
A ski resort area in Idaho decided a few weeks ago that widespread antibody testing might be useful. The results of that survey are presented in this paper. (Medrxiv Paper) 917 people participated. After making adjustment for demographics, etc., the prevalence was around 23%. This meant that 80% of cases in the area were not detected by prior infection testing. Note that the study tested for antibodies against the nucleocapsid protein, and we saw from a recent piece of research that variability in that genomic area means it may not be the best one to test for, so prevalence could have been even higher than reported. The authors opine that the area is not yet close to population immunity, but that is likely wrong, because of inadequate antibody testing and lack of testing for T cells and cross-reactivity.
Another study on antibody development. (Medrxiv Paper) In this research 34 patients, about a third of whom had been hospitalized, were followed for several weeks post-infection. The authors concluded that being infected created a strong and lasting antibody response, including for neutralizing antibodies.
Finally, another paper looking more broadly at the immune response to coronavirus infection. (RS Paper) The researchers are from Germany and looked at 180 coronavirus patients and 185 healthy people. They were focussed on T cells and their role in providing adaptive immunity. The focus was identifying fragments of the virus proteins that were recognized by T cells. The spike protein and membrane protein were frequently targeted. Among healthy donors, certain fragments were also recognized by their pre-existing T cells, likely from seasonal coronavirus infections. About 80% of these healthy donors had some pre-existing T cell cross-reactivity to the current strain. In addition, they found that in over 50% of infected patients with limited or no antibody response, there was a strong T cell response. While antibody response appeared to correlate with disease severity, T cell response did not, again indicating the primacy of T cell responses to coronavirus infection. People with less severe disease actually had T cell memory repetoires that were broader than those patients with severe disease. So patients with severe disease may be as or more reliant on antibody responses for protection against re-infection.