BREAKING: A new type of test detects immune (T) cell response to the coronavirus, and may be a better indicator of prior infection with the virus than antibodies. 1/6
As some studies recently suggested, antibody levels drop not long after the acute infection resolves. That doesn't mean immunity also wanes, but it does mean that antibody tests may not be the best indicator of exposure to the virus. 2/6
It's been increasingly obvious meantime that T cells play an important role in Covid-19. But whither the T cell tests? We've heard about antibody tests since early in the pandemic because they are easy to make. Looking at T cells, OTOH, sounds like a nightmare. 3/6
The trillions of T cells present at birth each carry unique receptors on their surface in anticipation of all the pathogens we might encounter. (@settelab made me laugh with his description of a T cell thinking, "I've been floating around all my life, doing nothing."). 4/6
But that makes challenging to find the 20 or 30 cells that can recognize antigens from any one particular virus. Enter @AdaptiveBiotech in partnership with @Microsoft who thought to sequence the receptors, rather than look at the cells. 5/6
How painful is the traditional T cell method? and how does the new test work? And how will it help vaccines?
It's all in the story (plus some very cool immunology.)
NEW: We know children rarely get sick from the coronavirus. A new study shows that they make a less diverse and weaker set of antibodies than adults do, suggesting that they clear the virus much faster. 1/10
Why, you may ask, would weaker and narrower set of antibodies mean less severe infection? It seems counter-intuitive. But in fact, many studies have shown that the most severely infected people have much higher levels of antibodies. 2/10
In other words, a really strong immune response can be a sign that earlier immune defenses did not work, and can signal an immune system that is desperately trying to gain mastery over the virus — and sometimes failing. 3/10
As of Oct 29, there were at least 835K children infected with the corionavirus (61K in that last week alone.)
That represents 11% of total infections, according to the @AmerAcadPeds
@AmerAcadPeds Latino children are 73% of infected children overall. Of the 1,100 kids with MISC, 41% of children are Latinx, 35% are Black. And this is probably undercounted.
@AmerAcadPeds OTOH, lots of stresses on children from the pandemic and from schools being closed.
All right, here goes, with this latest round of papers and preprints. I don't vouch for the quality of any of them and certainly not the preprints, just noting some interesting and intriguing trends and findings.
1. First on the list is this preprint from many days ago that linked election rallies to an increase in Covid-19 hospitalizations, in one case by 15-fold
2. This one's interesting. We know by now that fomites pose low risk of infection, but this suggests that monitoring surfaces can be a good indicator of level of community spread
How are you all holding up? Shall I tweet out a second set of papers? Or are you too stressed to pay attention?
1. This Lancet Global Health Paper is from a while ago, but really sobering. Estimates that 1.7 billion, or 22% of the world, has at least one underlying condition for Covid risk and 349 mil or 4% are at high risk and would be hospitalized if infected
2. Really interesting preprint that found that seroprevalence in the slums of Mumbai was a whopping 54% compared with 16% in non-slums. But without the deaths you'd expect with that kind of prevalence
I'm going to tweet out a whole bunch of papers I've been looking at so we all have something to read. READY?
1/x
First, this paper in Blood suggests using T cells from recovered patients as therapies for Covid. Like convalescent plasma therapy but T cells instead of antibodies.
The perfect antidote to unwarranted fears about declining antibodies: Solid data showing the opposite. Here's news from Ania Wajnberg @florian_krammer et al that antibodies persist for at least five months. 1/x
@florian_krammer I've written about earlier data from this team, here in May, showing that most people, regardless of sex, age and severity of illness make decent antibodies: 2/x