COVID Update: How big a problem will future variants be?

I got an update from several top scientists. 1/
Quick review. Viruses continually mutate but can only mutate when they replicate. And so far we’re giving SARS-CoV-2 plenty of opportunities to replicate. 2/
Most mutations aren’t worth noting. They don’t increase hospitalizations. They don’t increase infectiousness. And they don’t cause problems for prior immunity. 3/
A fallacy pushed by anti-vaxxers is that vaccinations cause mutations.

It’s false. The more unvaccinated people, the more replication within cells as people mount a slow immune response— the more chances for the virus to mutate. 4/
So far the variants of concern that have taken hold in countries around the world have followed 1 of 2 paths for more cell replication— either evading vaccines or spreading more easily.

But so far none of these variants have combined both problems— evasiveness & contagiousness.5
Think of one path as going broad to more people (a more contagious variant is harder to catch) and another path as going deep (within a single individual to more cells).

One that had mutations to be the most rapidly growing & most evasive would be the most concerning. 6/
The vaccines that have caused the most trouble for vaccines in vitro & in reality (Beta, Iota, Delta+, Mu) have so far been outcompeted by the variants that spread more rapidly (Alpha and now Delta). 7/
Problematic variants that can’t grow as fast as Delta will be only a limited problem.

When we read about a Mu (0.1%) being a problem for vaccines, if it can’t outcompete Delta, it won’t take hold. 8/
So Delta, oddly, is defeating variants that would be more challenging for vaccines (and also monoclonals).

And until a variant that causes problems for the vaccine also spreads faster than Delta, it won’t become dominant. 9/
As an aside, Delta causes some problems for the vaccine but in a different way— because it replicates more virus so quickly that w/ lower antibody levels, immune response often isn’t fast enough to prevent symptoms. Cellular immunity does kick if to prevent hospitalizations. 10/
So why hasn’t a variant come along that has both negative characteristics? Will it?

The answer to the first question is largely randomness. There’s no reason why both types of mutations can’t exist in the same virus variant. 11/
The more opportunity, the more random things will happen. So it’s also the length of time of the pandemic, the spread & the too slow, too low vaccination rates that increases the odds. 12/
Will it happen?

We don’t know but we do know that vaccinating the globe and the US more quickly will reduce the odds.

In the scheme of viruses Delta already replicates very fast. Not close to measles, but arguably comparable to chicken pox. That’s a tall order for a mutant. 13/
So we could expect to see a lot of “problematic” mutations for the vaccines that never amount to much because Delta crushes them.

But what happens if we do see one that’s vaccine evasive that Delta doesn’t outcompete— or at least leaves room for it in some regions? 14/
There are a few key ingredients that must be ready: surveillance, vaccine development, regulatory & scaled manufacturing/distribution. 15/
We’ve taken a big step forward in surveillance with the CDC’s new forecasting center. Genetic sequencing need to occur however in many more regions of the US than it does now.

Countries around the world are also improving their ability to spot variants quickly. 16/
Once we identify a new variant, we can test its effectiveness against vaccines in the lab. If one is an evasive mutation, within 100 days we should have the capability to develop a new specialized booster.

By that time we should know if the variant is outcompeting Delta. 17/
The good news is that as long as a virus generates an immune response from the body, we should be able to make a vaccine that works (which is why HIV has been so challenging for scientists). 18/
Over the course of the year the Biden Admin has put together a pandemic resiliency plan that should allow for the rapid production & distribution of vaccines for new variants & new viruses.

The aim is 100 days for a vaccine & 100 days for full production. 19/
200 days sounds like a long time but if we have good surveillance & begin right away, remember how long it could be before a mutation is discovered & its proliferation depending on the origin. 20/
If the original COVID started circulating in China in the 4th quarter last year, it months before it started to spread significantly around the 🌏 .

If we are developing vaccines at pace, it could end up being only a short spike in most countries before a vax is ready. 21/
This will undoubtedly mean suffering in the place of the variant’s origin. And a lot of logistics (imagine a whole new global rollout). We will need to get better & better at it.

And of course each time face anew the challenges of vaccine hesitancy. 22/
Layered protections are essential. A vaccine plus a mask and good ventilation plus awareness of when spread is increasing in your community will keep everyone safest. 23:
Along with the development of an oral anti-viral, we are building the arsenal as a globe & as individuals to manage new variants but we have to use them.

Right now Delta is the devil we know. And while not our friend, it is at least the enemy of our enemy.

If we don’t want to deal with worse variants we know how to reduce the odds. Slow the spread. Accelerate global vaccinations. Take its potential seriously. /end
One of the scientists who informed this thread is Tony Fauci. He’s my guest on @inthebubblepod tomorrow.

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More from @ASlavitt

15 Sep
COVID Update: There is an amazing array of efforts, some not very visible, to tackle COVID.

If you want to know how COVID plays out, the variables are here. But there’s the fatal flaw: us. 1/
I can try to classify many of the efforts to address COVID as now (high impact progress we are working on now), med term (things underway but not immediate), and long term (potential big game changers). 2/
The now items are critical to saving lives today & reducing the odds of future variants.

Number one on that list is to vaccinate the majority of the globe by the first quarter. 3/
Read 25 tweets
14 Sep
COVID Update: With requirements rolling across the country, I called a company that implemented vaccine requirements last month.

Here is the experience & lessons for the rest of us. 1/
Background first. The company is based in the Midwest with 6000 people.

The workforce has salaried, factory workers and service center workers.

Their starting point was 70% of the staff vaccinated.

The CEO announced that by 10/1 everyone needed to be vaccinated. 2/
The first reaction was a 10% reduction in their employee satisfaction surveys— the first reduction in the history of the company.

Some people were quite upset. So the CEO began to try to understand people’s reasons for being unvaccinated & their objections. 3/
Read 24 tweets
12 Sep
This chart is interesting.
What it says is that Delta is spreading within households (that’s what Secondary Attack Rate means) at the same level as peak flu season.
Note the increase over last September.

It implies at least 3 things we should try to understand better. 1/
First, kids are getting COVID at school and infecting family members.

Policies preventing schools from protecting kids are failing the entire family including seriously at risk adults. 2/
Second, household infections are going to grow over the Fall and early Winter without more layered interventions. 3/
Read 4 tweets
12 Sep
COVID Update: Watching the reactions & meltdowns to the proposal that Americans are required to get vaccinated (or tested) to be around others.

There is so little actually controversial here but the sideshow is first rate. 1/
Real people by large majorities support vaccine requirements. We’ve had them for decades, even centuries with little controversy.

No governor has threatened to light himself on fire & blow himself up (until now). 2/
Like traffic lights, as inconvenient as they sometimes are, people are pretty ok with rules if they do things like keep kids safe, reduce deaths, and allow businesses to be open safely. 3/
Read 20 tweets
9 Sep
COVID Update: After recent FDA approval, society is moving towards, requiring vaccines at a rapid pace.

And that’s about to get another jolt. 1/
Over 5.5 billion vaccines have been administered around the world. Think about this from a safety standpoint. Rare things happen when they occur a few times per MILLION. So we’ve seen it all.

At this point the safety record would have to be called impeccable. 2/
Over 5.5 billion shots, given to people of all ages & health, you would expect everything to occur. Yet there are only very modest & rare adverse events.

Even anti-vax strategies seem to acknowledge this reality. 3/
Read 20 tweets
4 Sep
COVID Update: Over the long term the US could be among the countries with the highest cases, greatest risks of outbreaks, and largest home to new variants.

With people refusing vaccinations here, the globe is lapping the US very quickly.

We’ve now given out 5.4 billion shots across the globe.

45 countries, almost all of whom began well after the US, have now fully vaccinated more of their population than the US. 2/
Our low vaccination rates relative to the globe has put the US up there with 3-4 mostly unvaxxed nations as a leading hot spot.

And because of our lower vaccination rate, unlike other early vaccinated countries like Israel & the UK, US death rates are 2-3x higher. 3/
Read 16 tweets

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