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Slavitt is engaging in a bit of hyperbole. He is saying something like bullet proof vests stop bullets in their tracks. They actually don't. A bullet may get through if the velocity is high enough. More seriously, the vest alone cannot stop the bullet. A lot of the force of the bullet gets through to your body, and this means that getting hit by a bullet can still injure and possibly kill you even if the bullet is technically stopped. There are lots of things like this. Parachutes, for example. A parachute evangelist will say that parachutes make it safe to jump out of a flying airplane. Well, they don't. It is quite possible to die after jumping out of an airplane equipped with a properly functioning parachute. The thing is that it is massively safer if one is wearing a bullet proof vest when having to deal with bullets being fired at you, and it is massively safer if one has a parachute when jumping out of a flying airplane. A COVID vaccine doesn't actually stop COVID infections, but, like a bullet proof vest or a parachute, it makes a huge difference.

Israel is still less than 60% vaccinated. It is quite possible that reaching a 95% plus vaccination could stop the delta variant. Given the purpose of Slavitt's exhortation, I'll give him a pass on his exaggeration.

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From the CDC website:

"In summary, prevention measures will continue to be important during the period of vaccine deployment. As vaccination coverage increases, phasing out prevention measures for fully vaccinated people, ideally those measures that are the most disruptive to individuals and society, will be increasingly feasible."

The UK is looking like a natural experiment - removing all restrictions in the face of the delta variant as vastly the most common variant now.

Here in central California, mask-wearing seems to have become optional, with at least half the local population going maskless in stores. Assuming these people are all vaccinated (haha), it will be another test case on infection and transmission, as well as deaths. My county has stopped reporting on Covid - but I assume that any new surge in infections will force it to report again.

I read that Pfizer is pushing for a 3rd dose to cover the delta variant. I hope such a booster shot is available in the flu season.

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I don't think you can use the vaccine efficacy metric as an across the board deflater of COVID effects. The way the vaccine works is it pre-primes your immune system for the potential fight against the virus. The analogy I like to use, is that it gives your immune army somewhat realistic practice fighting it, so when the real threat come along its not completely unprepared -it knows several tactics that help,. It still needs to hone them, and that takes time. The bottom line is the effect of the preparation is that your immune system learns and adapts more quickly during the fight. It is only moderately effective stopping the initial infection, but as the seriousness the threat goes up the measured efficacy goes up. So its say 99% effective at staving off death, but maybe only 80% effective at avoiding mild symptoms. So what we get is its very good at protecting severe disease, but not so strong at protecting against mild or asymptomatic disease. The effect on

transmissibility is harder to determine. How much transmission risk do these mild infections create? I don't think we have the data to determine that yet.

Also we have other strains out there, Delta-plus and lambda, and we don't yet have good data on them, so determining the future course of the pandemic can't be done with any precision.

One data point we do have is that both the UK and Israel have vaccination rates comparable to ours, but Delta got there sooner. Both states have rapidly rising infection rates, but low death rates.

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