Shane Crotty Profile picture
Vaccine scientist. Immune system scientist. Professor, La Jolla Institute for Immunology (LJI), a non-profit scientific research institute.
Κασσάνδρα Παρί پری Profile picture RadiantLady Profile picture lila_ribeiro Profile picture very special episode Profile picture Rulito Profile picture 14 added to My Authors
26 Feb
(iv) Durability of immunological protection against COVID-19 is still unknown for each of these vaccines.
(v) The J&J 1-dose does quite well against the SA variant. That's a big deal! In contrast, the AstraZeneca vaccine appears to have almost no efficacy against that variant (~10% efficacy in confirmed cases).

(vi) Lastly, the J&J vaccine had substantial increases in neutralizing antibodies after two doses (T cells were not reported post-boost).…
Read 6 tweets
26 Feb
The J&J COVID-19 1-dose vaccine data have been filed with the FDA and are under review there (probably final decision tomorrow).
Here are my thoughts on the J&J 1-dose COVID-19 vaccine, now that the data are public.🧵

(Janssen=J&J = Johnson & Johnson) Vaccine name: Ad26.COV2.S
Executive summary:
🔵 1-dose. Very convenient! And easy to store.
🔵 Essentially 100% protective against death or hospitalization. Very good!
🔵 69% protection against symptomatic COVID-19. Just ok.
🔵 Similar protection against the South Africa variant (72%-->64%). Very good!
The FDA EUA package data are consistent with the statements in the J&J vaccine press release several weeks ago.

Here's my tweet thread from then:
Read 22 tweets
26 Feb
Obviously I can only speculate for now. Actually, let's be really clear:


IF there is an effect of COVID vaccines on long COVID (I don't want anyone to have unrealistic hopes without there being data from a well-designed clinical study!), the simplest options are:
1. The strength of the vaccine immunization serves to reset a homeostatic baseline to the immune system.

2. Exactly as Akiko said so well:

Read 7 tweets
26 Feb
Excellent paper on the human B cell response to COVID-19, by the fantastic Laura Walker. 🧵…
1,213 human monoclonal antibodies (!), showing substantial affinity maturation of the B cells over time.
A substantial fraction of the Spike-specific response is to RBD. Consistent with other work.
Read 7 tweets
16 Feb
This was really PHENOMENAL news. A big deal for the future of vaccine development broadly. And a big deal in the HIV vaccines field.🧵
Not only was a positive signal seen in 97% of vaccinated people, the signal was fantastically strong!
As noted by Bill Schief in his talk, this is probably the first vaccine trial to succeed in confirming its intended mechanistic hypothesis. A big moment for germline targeting vaccine design strategies!
Read 8 tweets
8 Feb
Well, that's a nice surprise!
What happens if you have had COVID infection before and you get a COVID vaccine?
Some observations last week are summarized here:
In a new pre-print by the excellent @McGuire_Lab , they report a big jump in neutralizing antibodies after a single COVID RNA vaccine immunization (Pfizer or Moderna).

That is the same thing observed by @florian_krammer and the Sajadi labs.…
Read 5 tweets
8 Feb
The AstraZeneca/Oxford (AZ) COVID vaccine (ChAdOx) results in South Africa are concerning. 🧵

* The AZ vaccine had 75% efficacy against mild COVID through October 2020.

* But only 22% efficacy more recently, with the SA variant  (aka B1351 or 501Y.V2)…
Penny Moore and Alex Sigal and colleagues now report on antibodies from AZ ChAdOx vaccinated people, and there was a dramatic loss of function against the B1351 variant. It appears to be more than a 20x reduction. A complete loss of neutralization in most individuals (~80%).
First, what to think of the antibody neutralization loss?

It is much steeper than reported by multiple groups elsewhere for COVID19 cases or other COVID vaccines. Multiple labs reported ~2x drop in neutralization of B1351 or related virus, with antibodies from vaccinated people
Read 16 tweets
8 Feb
This is a very nice study of the AstraZeneca/Oxford (AZ) ChAdOx vaccine in the UK (with a  challenging title!).…

There are several novel findings in this study, including:
* 75% protection against ASYMPTOMATIC infections, (w/new definition).

* Protection against symptomatic infections was similar for B117 (the UK variant).

* Even though ChAdOx antibodies were 9x weaker against B117.

* Protection against asymptomatic B117 appears mostly lost.
On the topic of vaccine protection from asymptomatic infections:

There have been limited data on vaccine protection from asymptomatic infections, which has important implications for transmission of virus.
Read 20 tweets
7 Feb
I am a big fan of this COVID immunity paper from @Anto_Berto . This was the first paper to longitudinally track viral loads AND virus-specific T cells in COVID patients quantitatively in the same study, from early time points. 🧵

The key observations are:

* Early T cell responses were associated with rapid control of virus and mild disease.

* Early antibody responses did not distinguish control of virus or disease severity.

* Peak viral loads were correlated with disease severity.
I talk about the importance of longitudinal studies from early timepoints post-infection in this review.…
Read 7 tweets
5 Feb
Hooray, the shiny colorful final version of our paper is out in Science! 😁🧵…
Explainer thread when it was first published in Science:
Read 4 tweets
4 Feb
Getting lots of questions about COVID vaccine safety, which is good! Here's a quick compilation of some resources on COVID vaccine safety.🧵
This covers the basics about the RNA vaccines and safety:

I did a Youtube video on RNA vaccines and COVID vaccine safety with the excellent @MedCramVideos . It has been very popular
(over 1 million views!)
Read 8 tweets
2 Feb
SIX successful COVID-19 vaccines! SIX! Three just in the past week! Extraordinary. The newest one is the Russian (Rus) adenoviral (Ad) vector COVID vaccine. The clinical trial data look really good at face value. 🧵…
92% efficacy overall, and 92% efficacy in people over 60 years old.
I will let clinical trial design experts weigh in on trial design features. I will comment on the basic outcomes and the immune responses.
Read 12 tweets
2 Feb
What about vaccinating people who have already had COVID? I get this question a lot. New answers now! 🧵…
Excellent and rapid work to find that, for people who have previously had COVID, one COVID vaccine dose gives a bigger antibody response than seen in COVID-negative people receiving a normal two dose COVID vaccine regimen.
One study by Viviana Simon & @florian_krammer and colleagues. And an independent stduy by Sajadi and colleagues in Maryland.
Read 15 tweets
30 Jan
1/ Now for the thornier data.
2/ I covered the great news from the Novavax COVID vaccine UK Phase 3 trial.
3/ I covered the excellent news from the J&J COVID vaccine Phase 3 international trials.
Read 28 tweets
29 Jan
1/ J&J COVID-19 vaccine. Single dose Ad26 (adenoviral).

Another important COVID-19 vaccine success!

Topline J&J vaccine efficacy reported to be 100% against serious cases of COVID-19 more than 28 days after immunization. Those are big!
2/ That includes USA, Latin Amer, and South Africa study sites. It will be important to see more data, because the initial press release was definitely thin on data. But, initial report 72% efficacy against "moderate to severe" disease. That is good for a single dose immunization
3/ The J&J COVID-19 vaccine generated good immune responses in people after one immunization, but there was a substantial boost to the antibody response after a 2nd immunization. A 4x gain. (T cell responses after the 2nd dose were not reported)…
Read 15 tweets
29 Jan
1/ Novavax UK first:
~90% protection again any symptomatic COVID-19. And that high level of protection was accomplished under conditions of very intense community transmission in the UK, which is a high bar. 1/n
2/ (i.e., most likely a higher bar for protection than USA summer transmission, or anywhere with low level SARS2 transmission). And that was under conditions of high prevalence of the "UK variant" (B117), which is significantly more transmissible than the parental SARS2 strain.
3/ The Novavax vaccine was quite protective against both the parental strain and the UK variant, which is welcome news.
Read 15 tweets
12 Jan
1/ Here's my review on adaptive immunity to COVID-19 and SARS-CoV-2. I hope you find it useful. It was a lot of work. Thanks to Prof Alex Sette @SetteLab and others for direct contributions and broader input over the year!… @CellCellPress Image
2/ And thanks to all of the amazing scientists and labs around the world that have done so much work making incredible progress on these challenging COVID-19 immunology topics in the past year!
3/ FYI, here's the right version of Figure 1. It should be updated in the next version posted online. Image
Read 5 tweets
9 Jan
1/ “I think this [study] is really important because there is a lot of fear and uncertainty at the moment about this specific question.”

“[the results are] not surprising, but it’s been really important to see some data.”…
2/ Definitely good news to see these data on the Pfizer vaccine working against the 501 variant. If anything, the vaccine works better against this variant.…
3/ It isn't the end of the story, because the UK / SA variants have mutations in addition to 501, but these vaccine data are an important piece of the puzzle. As noted in the article, more is expected from labs in the coming weeks, but these results are expected & encouraging.
Read 4 tweets
9 Jan
1/ One pre-print on B117 viral loads (i.e., B.1.1.7 SARS-CoV-2 ) found substantially higher viral loads (median 10-100 times). Another UK study found 3 times higher viral loads in people with B117 (Bonsall/Golubchik study).……
Read 7 tweets
6 Jan
1.  Our COVID-19 paper on Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection is out today in @ScienceMagazine !…
@ljiresearch @SetteLab @Dani6020
2. The immune system can remember viruses. And there are multiple different parts of the immune system that can remember a virus in different ways, so the immune system can fight the virus in multiple ways.
3. Our data shows that the body’s immune system remembers novel coronavirus for at least 8 months after COVID-19, and multiple different branches of the immune system remember the virus.
Read 8 tweets
31 Dec 20
1.  I am convinced that the new "UK variant" of SARS-CoV-2 (B.1.1.7) is a big problem. I look forward to seeing more epidemiology by more labs (not my area), but the overall picture plus these new viral load data now have me convinced. (my PhD was RNA virology)
2.  An analysis of 641 COVID-19 cases found "S-negative" (B.1.1.7 inferred) cases had 10 to 100-times higher nasal viral loads than 'regular' COVID-19. Virologically, that is a massive difference. It could easily explain higher transmissibility.…
3. The authors of that work are appropriately cautious in their interpretations (e.g. they didn't directly sequence confirm B.1.1.7 cases), and it will be very valuable to see similar studies from other sites. But, I find the data compelling.
Read 7 tweets