Thread by @erlichya

📢 The study we all waited for by the brilliant team at the VRC/@NIAIDNews

Should we wait for an Omicron-specific booster?
Short answer: No 🤯

Long answer: A thread 🧵👇

The main question that many people contemplate is should I wait for an Omicron-specific booster or not?

Eight 🐒 received 💉💉 of the regular (WT) Moderna vaccine.
Then, 41-weeks later, they were split into 2 arms:
1⃣Got a regular (WT) 💉 booster
2⃣Got an Omicron 💉 booster

2 weeks later, the team checked the neuts levels from each arm against various viral strains.
For ALL strains the neuts level of Arm2⃣ (Omi💉) were NOT better than Arm1⃣ (WT💉)
This was also true for Omicron 😳. Look at gray lines at w#43 in both graphs (WT: solid; O: broken)

Why? This is probably the Original Antigen Sin (OAS). The immune system already learned how a WT Spike protein looks like and lost some plasticity to learn the nuances of Omicron-spike. For non-scientists: think about it as if you're trying to speak in a foreign language➡️

After a certain age, no matter how hard you try, you still have a specific accent of your mother tongue and you cannot forget it. The same is true for your immune system: it cannot unlearn the "accent" of a WT spike.

Is it totally bad? I don't think so! First, it means that we don't need to wait for anything and @pfizer/@moderna_tx can produce at full speed the current vaccine. Moreover, 🇮🇱MoH recently showed that a fresh 4th dose really helps against O-infection and severe cases.

I already got a 4th shot and so are more than 600,000 Israelies, without any substantial side effects. We 4th boost virtually all requesting adults who are received their 3rd dose at least 4 months ago. Not a bad strategy!

Links:
Omicron booster in 🐒: biorxiv.org/content/10.110…
Israel 4th booster: medrxiv.org/content/10.110…

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CC: @EricTopol
@HelenBranswell
@dgurdasani1
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