[dabigv13]

All caveats about preprint papers apply, but good and interesting news from this paper.

Main takeaways seem to be that T-cell responses likely are important in responding to the virus, and may be why patients who don't produce a lot of antibodies can have asymptomatic or mild courses. 

Vaccines will likely need to also stimulate a strong T-cell response in order to provide durable immunity.

This is another tick in the column of evidence that suggests that while reinfection is possible, a second infection is likely to be much less severe. 

And finally, though only briefly mentioned and not really quantified, they did find some blood donors from 2019 had reactive T-cells, prior to the emergence of covid19. Notably only to the surface antigens, which have some homology to other coronaviruses, and hints again that prior exposure to other coronaviruses may give some individuals some immunity. Depending on how many people have crossreactive T-cells and the strength of that response, the threshold percentage of exposure/vaccination to achieve herd immunity could be less than the 60-70% predicted otherwise.

[dabigv13]

All caveats about preprint papers apply, but good and interesting news from this paper.

Main takeaways seem to be that T-cell responses likely are important in responding to the virus, and may be why patients who don't produce a lot of antibodies can have asymptomatic or mild courses. 

Vaccines will likely need to also stimulate a strong T-cell response in order to provide durable immunity.

This is another tick in the column of evidence that suggests that while reinfection is possible, a second infection is likely to be much less severe. 

And finally, though only briefly mentioned and not really quantified, they did find some blood donors from 2019 had reactive T-cells, prior to the emergence of covid19. Notably only to the surface antigens, which have some homology to other coronaviruses, and hints again that prior exposure to other coronaviruses may give some individuals some immunity. Depending on how many people have crossreactive T-cells and the strength of that response, the threshold percentage of exposure/vaccination to achieve herd immunity could be less than the 60-70% predicted otherwise.