Thread by @erlichya

Can BNT162b2 reduces transmission?
Excited to share our study using real world data.
An encouraging thread 🧵
👇👇👇

Since Dec 20, Israel has rolled a massive COVID19 vaccination program using the BioNTech/Pfizer. The program initially focused on 60+ individuals and then gradually moved to earlier ages. By now, 77% of 60+ received at least one dose! 💪🔥

The Ministry of Health reported that ~31,000 people were tested as positive after receiving at least one jab in various time intervals.

But do we see a lower viral load in these individuals?🧐

https://twitter.com/dvir_a/status/1356503858629984257

@MyHeritage runs the largest covid19 testing lab in 🇮🇱. This facility has tested so far over 2.7 million samples, with approximately 10K-20K tests/day. We use the same qPCR kits and the same procedure, allowing us to compare Ct values across time points.

vimeo.com/431159364/2975…

Ideally, we would love to know the vaccination status of each individual and compare between vaccinated and vaccinated.

But here is the problem: we don't collect health information of individuals!!! We simply have no access to this info.

Idea💡: we know the age of the person and the date of the test. Since vaccination was started with 60+, we can compare the average Ct value positives in this age group as a function of time and compare to 40-60 as a control. Here are the results:
[Red: 60+;Blue:40-60]

Do you see something interesting? In all Dec and early Jan, the average Ct values of the two groups is very similar. But by the end of Jan, we start to see a build up of a difference. Specifically, the 60+ positives show a weaker Ct values on average. More formally:
🔥🔥🔥

We then created a model that estimated the difference in Ct due to vaccination, taking into account the daily vaccination rates in each group and the effectiveness:

This analysis predicted that the expected viral load
of vaccinated individuals who are positive to SARS-CoV-2 to be between 1.6x to 20x fold lower than
unvaccinated individuals!!!

There are some caveats, but the results are encouraging. Vaccinated individuals have lower viral load, which suggests lower transmission rates! We hope that these results will encourage more young people to vaccinate. They can protect their families and not just themselves.

Final notes. This work started on Thursday and conducted mainly by @PetterElla, which is a true ninja. Ella is a member of the @Myheritage team but also @UCLA first year PhD student. Quite amazing. Authors: @AsafYounger, @dvir_a, Danit Levi, Orna Mor, and Neta Zuckerman.

The paper was uploaded to @biorxiv_bioinfo and you can find it here. Feedback welcome:

github.com/ellapetter/COV…

Also thanks for @segal_eran for valuable discussions!

I had some typos in this thread due to not sleeping in the past three days. Sorry.

In the next tweet, I am reattaching Fig. 1 with the *correct* legend.

Blue: 60+
Red: 40-60.

You can clearly see that only in late Jan positive samples of 60+ individuals who have been vaccinated more => less viral load.

More results came this morning that corroborate our findings! These data by the amazing @RoyKishony is a direct comparison of vaccinated individuals based on qPCR of a different lab. The Ct value difference is in the middle of our estimation 💪🔥. Boom!

https://twitter.com/RoyKishony/status/1358695273468469250

And updated link to @medrxivpreprint
medrxiv.org/content/10.110…