This conclusion is based on the following new developments over the past month:
- Remained high levels of vaccine hesitancy
- New variants that may lower vaccine efficacy
- Rollout of the J&J vaccine (efficacy ~70%)
- Delayed arrival of the children vaccine
That said, herd immunity does not have a hard threshold, and being close to herd immunity may be sufficient to prevent large outbreaks.
Our goal should not be to reach "herd immunity", but to reduce COVID-19 deaths & hospitalizations so that life can return to normal.
From my recollection, this was the goal last year, to have a vaccine that would reduce deaths and strain on our healthcare system.
But now the messaging has shifted to "getting at least X% of the population vaccinated in order to reach herd immunity".
I believe this new public health messaging that herd immunity means "X% of people vaccinated" is flawed.
It seems to ignore the fact that:
1) Vaccines do not provide 100% immunity 2) Nor do they stop 100% of transmissions 3) ~30% of population have already been infected
I sincerely hope that any future discussions regarding herd immunity discuss those overlooked facts.
Even better, I hope we can move away from those discussions & focus on more urgent issues, like how low should hospitalizations/deaths be before restrictions can be relaxed?
In my opinion, guilting people to get vaccinated in order to achieve a collective "herd immunity" may not be the best way to do this.
Instead, we should encourage vaccinations as a path to a return to normal.
I like to believe that we've learned from the mask debacle.
Statements like "we will not reach herd immunity until end of 2021" serves little purpose other than incites fear in the general population that we must somehow wait another 9-10 months to return to normal.
covid19-projections.com projects that vaccine supply will likely outpace demand by April. I agree with @ScottGottliebMD that we need to think about what's next, and how we can better encourage people to get vaccinated.
I must add the usual disclaimer that I am not a public health expert or epidemiologist, and some of the opinions are my simply own based on the work I've done over the past year.
If I said anything inaccurate, please let me know and I will correct it.
To summarize, theoretical herd immunity is unrealistic and should not be the endgame.
The endgame is the widespread availability of COVID-19 vaccines that virtually eliminates severe illness.
And we are just a few months away from reaching that goal.
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This seems to confirm analysis announced by White House Data Director @cyrusshahpar46 that shows that the majority of delivered first doses have already been administered.
A month ago, I reported on @CDCgov's overestimate of true infections in the US.
It appears that last week, the CDC significantly lowered their estimates. It now closely matches covid19-projections.com's latest estimate of ~83M infected (~25% of the population).
My thread from last month is below, where I highlight the flaws in the CDC's original estimates (91M infections through November 2020 and a 7:1 infections to case ratio).
"Since the previous update, CDC has received additional data about the proportion of persons with symptomatic illness who seek [..] testing services. The higher values of health-seeking behavior result in lower estimates of infections"
Jan 20 Weekly Update: New vaccinations (750k/day) are still increasing, but at a slower pace. 1st doses saw a 30% increase over last week, compared to 76% increase the week before.
The @CDCgov page currently claims 11M people have initiated COVID-19 vaccination, but the underlying data suggests that it's actually 11M *doses*.
This is quite misleading, and I hope this error is corrected ASAP.
I took some time to correct for this myself. Our vaccination page now breaks down administered doses into 1st & 2nd doses: covid19-projections.com/path-to-herd-i…
According to our estimates, 10M people (not 11.1M) have received at least one dose. Out of those 9M, 1.1M have received both doses.
After this adjustment, the current pace of new vaccinations is ~4M people per week. Even if we double that pace, it would take 9 months to vaccinate everyone.
As of now, ~15% of the daily doses given are used as a 2nd dose (114k / 747k). I expect this fraction to grow over time.