Thread by @ASlavitt

COVID Update January 3: Tonight a thread I’ve been working on for a week. The best we know about the impact of the South African strain.

And the impact on the vaccine from lots of conversations.

Follow here if interested. 1/

To begin with we are back to assuming a modest humble position that there is now a plot we don’t know just like we were early in the virus. 2/

When we are in the “there’s a lot we don’t know” stage, I like to air on the side of caution. Risking being wrong is no reason not to act. Acting wisely with the best we know to save the most lives. 3/

What we know about the most significant variances is that they are more infectious. That’s why we noticed them.

Important and subtle point I keep hearing: the virus is mutating in less visible & measurable ways that we can’t see as easily & therefore can’t address. 4/

As we vaccinate more people these other evolutionary mutations are likely to become more visible. But we have to deal with the ones in front of us first. The one first spotted in South Africa has mutated several things at once & there is more nervousness about the vaccines here.5

Because we don’t know how much of the virus we missed we could be seeing a jump in cases compared to no mutations (lowest line) anywhere from the green (we haven’t missed much) to blue (there is a lot more than we know). 6/

So if you look at the curve on the right, the space under the curve between the colored lines & the low lines represents excess deaths from the mutation. It’s a big range— anywhere from 20,000 to 260,000 additional deaths— assuming our current projected rate of vaccinations. 7/

There are many simplifying assumptions here but the magnitude is worth understanding. 8/

Next question— why? Isn’t this supposed to be no more deadly?

Think of the virus as being easier to attach to a cell. One way to think about it is if today it normally requires 1000 particles to cause infectiousness, the new strain requires about 60% fewer or 400 particles. 9/

If the virus spreads more easily, it will infect more high risk people who will be in need of hospitalization. It also prolongs the spread as the graphs show.

It’s fattening the curve not flattening it. 10/

What about kids? Why is it impacting more kids?

Kids aren’t actually more susceptible relative to others. They are more active. If the threshold is 60% lower, everyone is more susceptible. So more kids are just seeing a bigger jump. 11/

Now to the most speculative topic. How will the vaccines respond? Will the mRNA vaccines which have ad it’s benefit the tailor made nature of the reaction? 12/

There are labs around the world right now with assays of all the vaccines trying to answer that question. They are testing the sustained immune response but aren’t able to test t-cell response. 13/

They require 5 weeks or so to get definitive answer on how effective the vaccines are and I have data points that are too early to share. Too unreliable. So best to say we don’t know. But here’s my sense... 14/

My sense is that all the vaccines work on the new strain but not at the same rate. And that the vaccine platforms have different levels of effectiveness. But those calculations matter less than some of the important likely conclusions...15/

1. If 15 minutes of exposure would cause an infection before, it is safest to assume that spending 6 minutes around the new strain could have the same effect.

Again on the conservative principle. 16/

2. We should be more careful with kids. They should circulate less or will become vectors. Like mosquitos carrying a tropical disease. Of course they can become sick themselves this way.

I’m not sure what I would say about schools besides wishing Trump had built testing up. 17/

3. We do need to assume that this is far more widespread than we know given how little priority we placed on sequencing. So I’m assuming it’s near me even though we don’t know. 18/

I took my son to a store today & went inside briefly. It was pretty empty. But I was 60% more nervous & tried to get out 60% faster while yelling at my son 60% louder through my mask. Zach thinks I’m 60% more annoying. 19/

4. There will be a sustained battle against Covid that won’t be simple. Our vaccinations need to be good and efficiently delivered and likely continuously evolving. We will need to continually vaccinate in all likelihood. 20/

5. This raises additional questions— 1 vaccine for all before 2 for all, more efficient & different cut offs.

I’m going to stay out of that debate. Others with informed opinions are opining. It is clear we should look at everything. 21/

When everything started I took plenty of criticism for suggesting we should assume this was going to be a public health disaster. I get it. Some on Twitter live to criticize. But human lives once lost are gone. And I for one will take the precautionary principle. 22/

We will learn more. But given where we are right now, being smart, being honest, and adjusting along the way as we learn more is the best way to go. That way we can best meet every challenge. /end