Thoughts on Antibody Persistence and the Pandemic

A second paper, published on Thursday in the journal Nature, suggests that even low levels of antibodies might be enough to thwart the virus. “It does appear that even low levels of certain antibodies have potent neutralizing capability,” said Dr. Rasmussen, the Columbia University virologist. “Low antibody titers don’t necessarily determine whether a patient will be protected from reinfection.”

Un élément qui ressort de plus en plus c’est la possibilité d’anomalies radiologiques et/ou biologiques chez les personnes cliniquement asymptomatiques.

Convergent antibody responses to SARS-CoV-2 in convalescent individuals | Nature
▻https://www.nature.com/articles/s41586-020-2456-9

We Still Don’t Fully Understand The Label ’Asymptomatic’ : Goats and Soda : NPR
▻https://www.npr.org/sections/goatsandsoda/2020/06/23/864536258/we-still-dont-fully-understand-the-label-asymptomatic

Entre autres parce que des lésions pulmonaires peuvent exister sans manifestations cliniques.

Thoughts on Antibody Persistence and the Pandemic | In the Pipeline
▻https://blogs.sciencemag.org/pipeline/archives/2020/06/22/thoughts-on-antibody-persistence-and-the-pandemic

... when you hear of patients who are infected but are showing no symptoms, you could have a mental picture of a stronger immune response that’s keeping the virus knocked down more. But it’s clearly not that simple: this paper shows that the asymptomatic patients had a weaker antibody response that tended to disappear during the convalescent phase. That’s the result that’s gotten a lot of attention – as it should – although it’s important to not run with it too quickly. Remember, there is more than one type of immune response – you have T cells pitching in as well. That response is one of the great unanswered questions of the epidemic, from what I can see.

[...]

Everyone will have seen the various population surveys with antibody testing that have suggested, in most cases, that a rather small percentage of people have been exposed. Think of the various ways you could get such a result: (1) it’s just what it looks like, and most people are unprotected because they have so far been unexposed. (2) the antibody results are what they look like – low exposure – but people’s T-cell responses mean that there are actually more people protected than we realize. (3) the antibody results are deceiving, because (as this latest paper seems to show) the antibody response fades over time, meaning that more people have been exposed than it looks like. And that means you can split that into (3a) the antibody response fades, but the T-cell response is still protective and (3b) the antibody response fades and so does the T-cell response. That last one is not a happy possibility.

You can extend this thinking to the effects of the coming vaccines.