Apoorva Mandavilli Profile picture
Reporter @nytimes on mainly #covid19 Winner 2019 Victor Cohn Prize. Before: Founding EIC @Spectrum, co-founder @CultureDish DMs open OR Apoorva@NYTimes.com
mike norrie Profile picture Karen Salitis #BidenWonTrumpLost Profile picture Aviva Gabriel Profile picture Claudio Calligaris Profile picture Stepan Spinka Profile picture 12 added to My Authors
29 Nov
NEW: People with Covid-19 are most infectious one to two days before symptoms begin and for five days afterward, according to a new analysis. So should isolation periods be shorter? 1/6

The results are based on a new meta-analysis, comparing the kinetics of the new coronavirus with SARS and MERS, and led by @mugecevik et al. They offer an intriguing possibility: People could isolate as soon as symptoms start, and get a test *after* the 5 days of isolation. 2/6
Right now, most people get tested a day or two after symptoms begin and get results 2-3 days later if they're lucky--so after they're pretty much done being infectious. They also can't often complete the 10 day isolation the CDC recommends. 3/6
Read 6 tweets
23 Nov
NEW: It's been said often and it sounds true: Small social gatherings -- people getting together with family and friends -- is driving the current surge.

But is it, really? I looked at the data, and they do not support this claim. 1/x

Let's be very clear upfront: This doesn't mean social gatherings are safe. Given community rates in most places, nothing is truly safe, and social gatherings undoubtedly do contribute to the spread. This is NOT an excuse for anyone to keep or make big Thanksgiving plans. 2/x
The question I asked was: Is there data to suggest that social gatherings are the "engine" of the surge, as officials keep saying? The answer is no. 3/x
Read 10 tweets
20 Nov
If anyone needed reminding that peer review is not proof of quality and preprint does not mean sketchy, just look at the two studies I wrote about this week.

I would rank the immunity preprint by @profshanecrotty and @SetteLab over the Danish mask study any day of the week
@profshanecrotty @SetteLab A better approach is to look at each study on its own merits. Read the paper, talk to experts, ask tough questions. I wish people would stop treating peer review like an infallible seal of approval
@profshanecrotty @SetteLab Over the course of my career, I've had to read thousands upon thousands of peer reviewed papers. And I would say maybe 400 were excellent. The rest... a waste of time, paper and effort
Read 5 tweets
19 Nov
MORE GOOD NEWS: Deaths related to H.I.V. in the United States fell by almost half from 2010 through 2017, regardless of sex, age, race or region. 1/4

But as with all good news, there are caveats. Women, Black people and those of multiple races showed much smaller gains in survival rates. And death rate in the south is twice that in the northeast. 2/4
Also, how will the pandemic change these trends? And what about access to testing, preventive therapy, treatment and care? No one knows quite yet, but there are troubling signs of declines in all of those metrics. 3/4
Read 4 tweets
19 Nov
You may have already moved on from yesterday's controversy over masks. But given the surge pretty much everywhere, it's important for us all to understand what we know about masks' usefulness, and what we don't.

Here we go: 1/7

First of all, among public health experts, there is near-unanimous endorsement of universal mask mandates to shield people from the virus and slow the pandemic. That's not in question. 2/7
But let's be precise about what we mean by masks, because they're not all equal. N95s are best, surgical masks are great, but the avg person doesn't need either. In fact, in some studies, well-made cloth masks did as well as surgical. Plus cloth masks are green/recyclable 3/7
Read 7 tweets
17 Nov
THE GOOD NEWS: Immunity to the coronavirus might last years, maybe even decades, according to a new study — the most hopeful look yet at this issue. 1/x

What this means: Most people have been infected (more than 90% or so) will be protected from reinfections for a very long time. And vaccines — which generally provide stronger, longer-lasting protection — may do even better. 2/x
What it also means: We probably will not need to vaccinate people every year as we had feared, giving us a fighting chance to contain this pandemic once vaccines are distributed. 3/x
Read 8 tweets
13 Nov
NEW: Have you been wondering if the CDC has, in recent weeks, seemed to reclaim some measure of its independence?

You weren't wrong.

The CDC has been sidelined and silenced almost since the beginning of the pandemic. But something changed in the fall: The big fight about the administration's meddling in the prestigious MMWR reports, the election, and the dangerously rising case numbers 2/x
“We couldn’t allow ourselves to be politicized at this moment in time,” one senior CDC scientist told me. “We weren’t going to spend time licking wounds and worrying about the past." 3/x
Read 5 tweets
10 Nov
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
Read 6 tweets
5 Nov
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
Read 10 tweets
4 Nov
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.
Read 4 tweets
4 Nov
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

Read 11 tweets
3 Nov
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

Read 10 tweets
3 Nov
I'm going to tweet out a whole bunch of papers I've been looking at so we all have something to read. READY?

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.

And here's a press release for that T cell paper, in case you're interested: eurekalert.org/pub_releases/2…
Read 11 tweets
28 Oct
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

@florian_krammer Or here in July, when they reported data from 20,000 people showing the antibodies persist for at least 3 months. 3/x

Read 4 tweets
27 Oct
The headlines, all of a sudden, are everywhere. UK study showed antibodies to the coronavirus decline so we're all doomed. No immunity, no vaccines, no herd immunity.

People, we have enough real things to worry about. Do not worry about this. 1/x

First of all, antibody levels are *supposed* to drop after the infection clears. Imagine if they didn't: Your blood would be a sludge of every type of antibody to every pathogen you've ever encountered. Hence my surprise yesterday at this paper 2/x

In the British study, in 27% of people who were positive at first, they dropped below detection limit. But the test has 84% sensitivity, and we know not everyone makes really high levels of antibodies after coronavirus infection (although nearly everyone makes some) 3/x
Read 9 tweets
27 Oct
A quick thread on what this new article showing worrying signs of autoimmunity in some Covid-19 patients means 1/6

In about 70% of people who were severely or critically ill with Covid-19, Emory researchers saw what are called "autoantibodies" -- auto meaning self. Instead of binding fragments of viral RNA, these antibodies glom onto human DNA. 2/6
Normally DNA is cloistered inside the cell. But under high inflammation (as in acute viral infection), cells can explode, strewing the arena with DNA fragments, and confusing antibodies. Their presence may explain some aspects of severe Covid 3/6
Read 6 tweets
26 Oct
ICYMI: On Thursday, we published a story suggesting that elementary schools, especially, do not seem to be seeding clusters of infection. As all articles on this topic do, it made some people angry, so... a thread for people who did not bother to read it or maybe misread it. 1/x
First, what the article did not say. It did not say kids don’t get infected or that they don’t transmit. They do, on both counts. It did not say that schools are fine to open no matter what is going on in the community. 2/x
Community prevalence is important because if it’s high, it means some number of kids and staff will arrive at school infected, making it more likely that they will spread the virus to others. 3/x
Read 12 tweets
23 Oct
BREAKING: Universal mask use could prevent nearly 130,000 deaths from Covid-19 by next spring, and without mask use, the death toll could top 500,000, acc to new estimates. 1/x

These are extremely rough approximations, susceptible to all the flaws of modeling studies, but plausible nonetheless, experts say. We’re already seeing a fall surge. The trends will continue through to a peak in Jan, and hold at high levels till March, acc to the model. 2/x
If states ease all social distancing mandates, the death toll could hit a million by spring. But more plausibly, if states put some restrictions back in place because of rising rates, the number might be closer to 500K. 3/x
Read 6 tweets
19 Oct
NEW: The Great Barrington Declaration has received a lot of attention, especially from the Trump administration. How did they gain access? And what exactly do they envision? 1/x

Here are some of the main pts: 1) protect the older/vulnerable while letting young people get infected
2) No testing of asymptomatic people
3) No contact tracing. 2/x
BUT how exactly would this work? How do you define, let alone "protect the vulnerable," when a third of the population has underlying risk factors? And how do you physically separate them from the rest of the population? 3/x
Read 7 tweets
19 Oct
In August I wrote a story questioning whether PCR tests are too sensitive. Many clinical microbiologists and others took issue with the piece because they saw it as undermining the PCR. This Medium post raises some of those points: 1/x

The post makes some very important points about PCR, including the huge variability across machines of cycle thresholds (Ct) and even from sampling method. 2/x
The FDA's own analysis confirms this concern. See, for eg, this recent attempt at figuring out the analytical sensitivity of some of the tests with an EUA, the range is very wide: 3/x

Read 12 tweets
16 Oct
There are SO MANY concerns about rapid tests for the coronavirus but a real-world experiment in SF has found that Abbott's BinaxNOW is just as good as PCR at detecting people who are infectious

The study is small, and it has limitations. But the team tested people at a train station in a Latino neighborhood. Looking at a likely range for infectiousness (CT < 33), the test detected 15 of 16 cases picked up by PCR. 2/x
But not rapid tests are equal. and neither, by the way, are all PCR tests. One analysis by the FDA found massive differences in sensitivity, with another Abbott test, ID now, towards the bottom. 3/x
Read 6 tweets