Folks being critical or misunderstanding this very good @apoorva_nyc piece

5 points that this piece pulls together nicely

1. Last year, we all assumed herd immunity threshold (HIT) would be 60-70%. Now clear its higher

This is not tragic

2. HIT may be 80%. Seems high

But its possible we might get there. We're about 60% population immunity now

As we improve access, make vaccinations easier, open up to kids, will get into the 70s

3. HIT not an on/off switch. Its not like we hit 80% and disease disappears

Already, we are seeing high levels of population immunity have large effect on dampening cases

My thread from yesterday:

States like RI, MA, SD already at 70% population immunity. They might get to 80% before long…

4. We won't be done even if we get to 80%. We'll need to monitor variants, vaccinate the world, continue testing, etc

5. But this is all manageable. We'll settle into a new equilibrium as we do with many viruses

And COVID won't dominate our lives. And that's what matters

So as we get into summer and fall

No we may not hit herd immunity

But infection numbers will be low

Vaccinated folks will be mainly safe

And with better treatment, infections may become less problematic

And life will return to a recognizable normal

And that'll be good


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More from @ashishkjha

2 May
At what point should we see cases in US begin to drop sharply from vaccinations?

Complicated but experience from Israel says 45-50% of population vaccinated

US is shy of that

But some states past that threshold

So do we have evidence its working there?

Why yes we do

Lets look at top 5 vaccinated states


All >50% of population 1+ dose

So what's happening with cases (c/w 2 wks ago)?

NH down 44%
MA down 37%
CT down 40%
VT down 46%
ME down 42%

I know, all New England states

Lets look broadly at cases & vaccinations

If we take the 10 states with largest drop in cases

Average vaccination rate 49.8%

The 10 states where cases actually rising?

Avg vaccination rate 39.9%

It appears somewhere around 45-50% population vaccinated (65% or so adults vaccinated)

cases really turn down

Read 4 tweets
26 Apr
While the world is struggling with the pandemic, things here in the U.S. have turned decidedly better

And that's very helpful

Let's see where we are:

Infection numbers fallen below 60K/day for first time in a month

This time, I think it'll stick



Last time the US got below 60K/day, we started rising again

How do we know that won't happen now?

Because in mid-March, when last mini-surge began, 21% of the population had been vaccinated

Today, we're twice that

Is 42% getting at least 1 shot enough?

Of course not

But 42% close to number at which we should see steady declines in infections

In Israel, once 45% of population was fully vaccinated, case numbers started to plummet

Several U.S. states approaching that

So while some states may still struggle, we should be on a better path

Read 4 tweets
15 Apr
CDC's vaccine advisory committee ACIP met today to advise on J&J pause

After thoughtfully discussing what we know & don't know about rare clotting events, they punted

The advisory committee decided not to advise

This was a mistake. J&J should be un-paused soon

Initial pause by FDA on Tuesday was a close call

But I supported it

A few days to alert people, begin process of collecting more data, advise physicians -- all made sense

Now advisory panel wants to return in 7 - 10 days to discuss further

The risk-benefit here is all wrong
Nearly all the adverse events are in women 18-49 years old

Cerebral Venous Sinus Thrombosis (CVST), the clot seen with J&J, is known to be more common in young women

Suggests that young women probably the group at high risk

This actually gave ACIP a smart way forward

Read 9 tweets
10 Apr
What's the state of the pandemic in the US?

In last month

B.1.1.7 and other variants have become dominant

90M vaccines have gone into arms

Cases are up about 20%

Here's the key graph for US since Feb 1

Its a Rorschach test

I see it as mostly good news

Obviously state of pandemic varies widely from state to state (e.g. Michigan)

But here are the 5 largest states in US (by pop)

35% of Americans live here

NY high, slowly drifting down

FL, PA rising slowly

CA, TX low, staying there
And a few other things have happened

77% of people >65 have had at least 1 shot

44% of all adults too

And given this, I think we are likely to avoid a serious 4th wave

That doesn't mean we won't see spikes (see Michigan)

Or that we are at Herd Immunity (we aren't)

Read 6 tweets
4 Apr
Since January, vaccine demand has outstripped supply

This will soon change


Base on how things are going

By around May 5, every American who wants a shot will have gotten their first

And that's pretty close...and exciting!

So lets do some simple math

Quick thread
There are 255M adults in the US

According to latest @KFF report, 62% of folks have gotten the vaccine or want it ASAP

That's 158 M people

And another 17% want to wait and see = 43M folks

We've already given at least 1 shot to 105M people

That leaves 53M folks who want vaccine ASAP but haven't yet gotten it yet

We are vaccinating about 1.7M new folks a day

So on May 5, that should get us to 53M newly vaccinated

It may be a bit later if some of the 43M wait/see folks decide to get vaccinated now

Read 4 tweets
2 Apr
As we start April, lets make it our transition month

We start with rising cases, deaths

Lets end it with falling infections

By keeping public health measures in place

And vaccinating!

1 in 2 Americans likely has some immunity to SARS-CoV2

By May 1, should be 3 in 5

50% of Americans with some immunity today?

Seems high, no?

Actually, pretty reasonable

Based on CDC, others, probably 30% of Americans have been infected

And now, about 30% of Americans have at least 1 shot

Assuming random overlap, gets us to about 50% with immunity
This is why our spike in cases much less scary (so far) than that in the EU

Higher population immunity (infections + vax) here blunting a lot of the effect of B.1.1.7

Each week, vaccines add another 2.5% of Americans to pool of folks with some immunity
Read 5 tweets

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