# Covid vaccine effectiveness rate (including against variants)
**URL:** https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133
**Category:** The Quarantine Zone
**Tags:** covid-quarantine
**Created:** [August 6, 2021, 1:14am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133 "2021-08-06T01:14:33Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Heffalump\_and\_Roo](https://boards.straightdope.com/u/Heffalump_and_Roo)
#### Post date: [August 6, 2021, 1:14am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/1 "2021-08-06T01:14:33Z")
Continuing the discussion from [Coronavirus COVID-19 (2019-nCoV) Thread - 2021 Breaking News](https://boards.straightdope.com/t/coronavirus-covid-19-2019-ncov-thread-2021-breaking-news/929428/2019):
> [@Coronavirus COVID-19 (2019-nCoV) Thread - 2021 Breaking News](https://boards.straightdope.com/t/coronavirus-covid-19-2019-ncov-thread-2021-breaking-news/929428/2019):
>
> @asahi himself says that the CDC’s figure is 90%, and says that that figure is wrong based on studies that aren’t actually about vaccine effectiveness. If you’re not going to accept the CDC’s numbers, then who will you accept?
>
> And no, 90% is not the number for the original strain. That number was over 99%. The vaccines are, indeed, less effective against the delta strain, but they’re still really, really effective.
>
> Yes, we should be taking other measures in addition to vaccines. But vaccines are still, by far, the most effective measure available. Discouraging vaccine use, as @asahi is doing, in order to encourage use of other measures is thus counterproductive.
I thought it might be helpful to start a thread on the Covid vaccine effectiveness rate based on studies.
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### Author:  [@Heffalump\_and\_Roo](https://boards.straightdope.com/u/Heffalump_and_Roo)
#### Post date: [August 6, 2021, 1:20am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/2 "2021-08-06T01:20:38Z")
Against the Delta variant:
> [@](#):
>
> - **Data so far suggests efficacy rates of more than 67 percent for the J&J vaccine, 72 to 95 percent for the Moderna vaccine, and 64 to 96 percent for the Pfizer-BioNTech vaccine.**
> **[Here's How Well COVID-19 Vaccines Work Against the Delta Variant](https://www.healthline.com/health-news/heres-how-well-covid-19-vaccines-work-against-the-delta-variant)**
>
> In the fight against the Delta variant, here's how the Pfizer-BioNTech, Moderna, and Johnson & Johnson COVID-19 vaccines measure up when it comes to protection. A new study found the Moderna vaccine was 76% effective against the Delta variant,...
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [August 6, 2021, 1:33am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/3 "2021-08-06T01:33:36Z")
> [@Coronavirus COVID-19 (2019-nCoV) Thread - 2021 Breaking News](https://boards.straightdope.com/t/coronavirus-covid-19-2019-ncov-thread-2021-breaking-news/929428/2020):
>
> Please show me where I discouraged vaccine use in order to encourage other measures. I’ll wait.
> [@Coronavirus COVID-19 (2019-nCoV) Thread - 2021 Breaking News](https://boards.straightdope.com/t/coronavirus-covid-19-2019-ncov-thread-2021-breaking-news/929428/2020):
>
> But no, I am in no way arguing against vaccines, and I’ve stated clearly that vaccines are still effective at preventing the worst outcomes - that still holds up in all of the data that have been collected across the globe. So in that sense, yes, I agree that vaccines still do their job.
How about this post?
> [@Coronavirus COVID-19 (2019-nCoV) Thread - 2021 Breaking News](https://boards.straightdope.com/t/coronavirus-covid-19-2019-ncov-thread-2021-breaking-news/929428/1999):
>
> And now surveillance data from the UK is starting to confirm that Israel was right and CDC was wrong. Vaccine efficacy? About 50-60%. There you have it, folks: **the vaccines are NOT 90% effective.**
You’re taking a study that isn’t about vaccine effectiveness, and you’re using it to say that the vaccines aren’t very effective. You say that you’re not discouraging people from getting the vaccines, and I’m sure that’s not your intent, but incorrectly stating that the vaccines are less effective than they actually are will nonetheless have that effect.
The vaccines are still extremely effective at what they were designed to do, even in the face of new variants. It turns out, to the surprise of nobody but the pessimists, that they’re also somewhat effective at preventing infection. That’s a nice added bonus, in addition to their primary effect.
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 1:35am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/4 "2021-08-06T01:35:03Z")
For the record, I am NOT discouraging vaccine use. If anything, I am considering the possibility of a third jab. I wish we had the Astra Zeneca vaccine so that I could mix and match. I love, love, love the vaccines. My heresy was pointing out that CDC’s data is old and no longer correct. Our best vaccines are almost certainly not 90% effective at stopping transmission. I could accept that they are somewhere between 39% and 88% - most likely not 39% effective and most likely not 88% effective but somewhere in between.
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### Author:  [@Tfletch1](https://boards.straightdope.com/u/Tfletch1)
#### Post date: [August 6, 2021, 2:14am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/5 "2021-08-06T02:14:08Z")
@asahi, it would be helpful if you were more precise in your language particularly in what you are defining as effectiveness. Also, it looks like you were incorrect when comparing the study in Israel to that of the UK study that you referenced. And your description of the CDC is at best misleading. Your variables are:
1. Variant
2. Asymptomatic infections
3. Mildly symptomatic infections
4. Viral loads and transmission (seriously conflicting are arising from differences in methodology)
5. Hospitalizations
6. Deaths
You can start with the CDC’s science brief here and tell us where the CDC is ‘wrong’.
> **[Coronavirus Disease 2019 (COVID-19)](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html)**
>
> CDC provides credible COVID-19 health information to the U.S.
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 2:21am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/6 "2021-08-06T02:21:56Z")
1. Variant: That’s easy when you consider that Delta variant accounts for **95% percent of all cases**. It’s obvious which variant matters now. Which variant was pervasive in April, May, or even June, doesn’t matter - at all.
2. Asymptomatic infections – That would be great, but since the CDC decided to stop tracking breakthrough infections that don’t result in hospitalizations, we won’t know the answer to that question in the United States. Good news is, Israel and the UK have been doing a better job of keeping track of that data.
3. Mildly symptomatic infections – see the above.
4. Viral loads and transmissions – what I can tell you is that, according to the CDC’s own research, viral loads of those who have vaccinations and those who don’t is quite similar in the first 3-6 days. The key difference is, as I’ve said before, is that the vaccinations have been effective at ultimately clearing out the virus within that time frame.
5 and 6 - I’ve said repeatedly that the vaccines, particularly the mRNA vaccines, have done their job in this regard – with regard to Delta\* There are some studies that have very serious concerns about how well the vaccines hold up against Lambda, though for whatever reason, Delta is fortunately outcompeting the Lambda variant.
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### Author:  [@Tfletch1](https://boards.straightdope.com/u/Tfletch1)
#### Post date: [August 6, 2021, 2:38am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/7 "2021-08-06T02:38:51Z")
Again, you’re not being careful enough to back up your assertion in the other thread that the CDC was somehow ‘wrong’. They never hid the data on breakthrough infections, including recently. They simply weren’t putting in the extra effort to investigate asymptomatic or mildly symptomatic breakthrough cases. Investigate means getting extra information including sequencing the genome, determining the type of vaccine and dose, getting age, symptoms, etc. In fact, they’re reporting data on mild to asymptomatic cases from states and other countries in the link. The head of the CDC talks about these data on TV. Fauci talks about the data on TV.
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### Author:  [@BigT](https://boards.straightdope.com/u/BigT)
#### Post date: [August 6, 2021, 2:45am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/8 "2021-08-06T02:45:18Z")
> [@asahi](#):
>
> For the record, I am NOT discouraging vaccine use.
The thing is that you never said anything that could plausibly be interpreted that way. Nor could anything you have said been interpreted as pushing propaganda.
Saying that you think vaccines decline over time in their ability to fight off variants is not plausibly read as saying that people should not get vaccinated.
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 2:45am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/9 "2021-08-06T02:45:38Z")
Show me where I suggested that the CDC was hiding data - **I never said that.** I don’t know where you got that from.
I said that they don’t have the data. They weren’t collecting the data. I am not the only person who has made that observation. Former FDA Commissioner Scott Gottlieb has said the same thing.
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 2:48am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/10 "2021-08-06T02:48:06Z")
No, not correct. I have said that vaccines prevent the worst outcomes – that is a reason to get vaccinated.
My problem is, when people say, “Oh wow, vaccines are like 90% effective, I don’t need to wear masks. CDC says we don’t need to wear masks,” that is a problem.
I really don’t understand why this is so hard to understand. I’m beginning to think that Americans are just…dumb.
ETA: Non-Americans, help me out here. I am living in a society that is addicted to “optimism.” Am I in the wrong here?
---
### Author:  [@Heffalump\_and\_Roo](https://boards.straightdope.com/u/Heffalump_and_Roo)
#### Post date: [August 6, 2021, 2:59am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/11 "2021-08-06T02:59:03Z")
> [@Tfletch1](#):
>
> You can start with the CDC’s science brief here and tell us where the CDC is ‘wrong’.
From that reference. I’m not trying to prove anything “wrong”, just pulling data from that resource. ETA: This is from the Alpha variant. The Delta variant info studies are in another post further down.
> [@](#):
>
> **Real-world vaccine effectiveness**
>
> Multiple studies from the United States and other countries have demonstrated that a two-dose COVID-19 mRNA vaccination series is highly effective against SARS-CoV-2 infection (including both symptomatic and asymptomatic infections) caused by ancestral and variant strains and sequelae including severe disease, hospitalization, and death. Early evidence for the Johnson & Johnson/Janssen vaccine also demonstrates effectiveness against COVID-19 in real-world conditions.
>
> **Table 1a. Effectiveness of COVID-19 Vaccination Against SARS-CoV-2 Infection and Symptomatic Disease**
>
> | Country | Population | Vaccine | Outcome | Vaccine Effectiveness\* |
> | --- | --- | --- | --- | --- |
> | United States[13](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref13) | General adult population | Pfizer-BioNTech or Moderna | SARS-CoV-2 infection | 89%\*1 |
> | United States[14](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref14) | General adult population | Pfizer-BioNTech or Moderna | SARS-CoV-2 infection | 86%\*2 |
> | United States[15](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref15) | General adult population | Pfizer-BioNTech or Moderna | Hospitalization | 96%\*1 |
> | United States[16](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref16) | Healthcare workers | Pfizer-BioNTech | SARS-CoV-2 infection | 97%\*2 |
> | | | Moderna | SARS-CoV-2 infection | 99%\*2 |
> | United States[17](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref17) | Healthcare workers, first responders, and other essential and frontline workers | Pfizer-BioNTech or Moderna | SARS-CoV-2 infection | 90%\*2 |
> | United States[18](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref18) | Healthcare workers | Pfizer-BioNTech | SARS-CoV-2 infection | 96%\*1 |
> | United States[19](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref19) | Healthcare workers | Pfizer-BioNTech or Moderna | Symptomatic disease | 94%\*1 |
> | United States[20](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref20) | Healthcare workers and residents in a skilled nursing facility | Pfizer-BioNTech | Residents: symptomatic disease | 87%\*2 |
> | | | | Residents: hospitalization | 94%\*2 |
> | | | | Healthcare workers: symptomatic disease | 87%\*2 |
> | United States[21](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref21) | Hospitalized adults ≥65 years old | Pfizer-BioNTech or Moderna | Hospitalization | 94%\*2 |
> | United States[22](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref22) | Health system members ≥18 years old | Johnson & Johnson/Janssen | SARS-CoV-2 infection | 77%\*2 |
> | United Kingdom[23](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref23) | Healthcare workers | Pfizer-BioNTech or AstraZeneca | SARS-CoV-2 infection | 90%\*2 |
> | United Kingdom[24](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref24) | Healthcare workers | Pfizer-BioNTech | SARS-CoV-2 infection | 86%\*1 |
> | United Kingdom (Scotland)[25](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref25) | Healthcare workers | Pfizer-BioNTech or AstraZeneca | SARS-CoV-2 infection | 92%\*2 |
> | United Kingdom[26](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref26) | Adults aged ≥ 80 years, including those with multiple underlying conditions | Pfizer-BioNTech | Symptomatic disease | 85%\*2 |
> | Israel[27](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref27) | HMO members \>16 years old | Pfizer-BioNTech | SARS-CoV-2 infection | 89%\*1 |
> | Israel[28](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref28) | Health system members | Pfizer-BioNTech | \<60 years old: SARS-CoV-2 infection | 93%\*2 |
> | | | | ≥60 years old: SARS-CoV-2 infection | 92%\*2 |
> | Israel[29](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref29) | General adult population | Pfizer-BioNTech | SARS-CoV-2 infection | 92%\*1 |
> | | | | Symptomatic disease | 94%\*1 |
> | | | | Hospitalization | 87%\*1 |
> | | | | Severe disease | 92%\*1 |
> | Israel[30](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref30) | General population ≥16 years | Pfizer-BioNTech | SARS-CoV-2 infection | 93%\*1 |
> | | | | Hospitalization | 94%\*1 |
> | | | | Severe disease | 94%\*1 |
> | Israel[31](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref31) | General population ≥16 years | Pfizer-BioNTech | Symptomatic disease | 97%\*1 |
> | | | | Severe/critical disease | 98% |
> | | | | Hospitalization | 97% |
> | | | | Death | 97% |
> | Israel[32](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref32) | Healthcare workers | Pfizer-BioNTech | Symptomatic disease | 97%\*1 |
> | Israel[33](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref33) | Healthcare workers | Pfizer-BioNTech | Symptomatic disease | 90%\*3 |
> | Italy[34](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref34) | Healthcare workers | Pfizer-BioNTech | Symptomatic disease | 95%\*1 |
> | Denmark[35](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref35) | Long term care facility residents | Pfizer-BioNTech | SARS-CoV-2 infection | 64%\*1 |
> | | Long term care facility staff | Pfizer-BioNTech | SARS-CoV-2 infection | 90%\*1 |
> | Sweden[36](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref36) | General adult population | Pfizer-BioNTech | SARS-CoV-2 infection | 86%\*1 |
The rates range from an outlier 64% to 99%.
The rates look slightly lower for asymptomatic infection.
> [@](#):
>
> **Table 1b. Effectiveness of COVID-19 Vaccination Against Asymptomatic SARS-CoV-2 Infection**
>
> | Country | Population | Vaccine | Outcome | Vaccine effectiveness |
> | --- | --- | --- | --- | --- |
> | United States[40](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref40) | General adult population | Pfizer-BioNTech or Moderna | Asymptomatic infection | 80%\*1 |
> | United States[18](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref18) | Healthcare workers | Pfizer-BioNTech | Asymptomatic infection | 90%\*2 |
> | Israel[31](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref31) | General adult population | Pfizer-BioNTech | Asymptomatic infection | 92%\*2 |
> | Israel[32](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref32) | Healthcare workers | Pfizer-BioNTech or AstraZeneca | Asymptomatic infection | 86%\*2 |
> | Israel[33](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html#ref33) | Healthcare workers | Pfizer-BioNTech | Asymptomatic infection | 65%\*3 |
---
### Author:  [@Tfletch1](https://boards.straightdope.com/u/Tfletch1)
#### Post date: [August 6, 2021, 3:02am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/12 "2021-08-06T03:02:12Z")
> [@asahi](#):
>
> I really don’t understand why this is so hard to understand.
As I’ve said twice now, you are not being specific enough in your posts. All you needed to say is that vaccines are now are less effective at preventing mild or asymptomatic infection by the Delta variant than earlier variants. I doubt @Chronos would have commented because he’s thinking about serious illness. Saying a vaccine is “not effective” sounds anti-vaxxer-ish to me.
---
### Author:  [@DMC](https://boards.straightdope.com/u/DMC)
#### Post date: [August 6, 2021, 3:07am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/13 "2021-08-06T03:07:54Z")
> [@asahi](#):
>
> Am I in the wrong here?
If you really want help, I’ll try. While I’ve stayed out of this particular argument, I understand completely where you’re coming from. With that said, the way you convey the message is very important.
> [@Coronavirus COVID-19 (2019-nCoV) Thread - 2021 Breaking News](https://boards.straightdope.com/t/coronavirus-covid-19-2019-ncov-thread-2021-breaking-news/929428/1999):
>
> And now surveillance data from the UK is starting to confirm that Israel was right and CDC was wrong. Vaccine efficacy? About 50-60%. There you have it, folks: **the vaccines are NOT 90% effective.**
If vaccine efficacy is 50%, then all I’m doing to myself by getting vaccinated is reducing my chances by half. That makes the vaccine seem pretty fucking weak, quite frankly. Sure, we both know there are other things going on besides those numbers and there is the responsibility to others that is also impacted, but that’s what a subset of people will see, because that’s what they’re looking for.
If, on the other hand, you focused on how to handle the Delta variant, i.e. through a harder push for vaccinations over all, increasing mask usage to earlier levels, and looking at potential boosters, you’d probably not get any arguments, certainly not from me. A more sober discussion about the different studies around efficacy of every vaccine/variant combination out there would probably fly as well, but only if it stays toned down a bit. You’d also be a lot less likely to fill the head of anti-vaxxers with more excuses about why they should ignore the CDC (which is all they hear, not which statements they should ignore).
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 3:10am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/14 "2021-08-06T03:10:06Z")
That’s on him if he overreacts to things I’ve posted – which is what anti-vaxxers do. You’re going after the wrong target here. I would argue that those who trot out old data over the new data that is available are the ones who are playing into the anti-vaxxers hands. I am being accurate here. If I may say so myself, I think I have the best read on vaccine accuracy of any poster actively posting. The vaccines are effective at preventing the worst outcomes but have declined substantially at preventing outcomes short of the worst ones - and that could be a problem for millions of people.
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 3:13am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/15 "2021-08-06T03:13:22Z")
The vaccines keep your ass out of ICUs and mortuaries – is that not reason enough to get the vaccines?
I’m talking about whether or not we should go back to living life as we lived it before the pandemic, because I am seeing a LOT of people who are doing just that, and THEY ARE SPREADING THE GODDAMN VARIANTS AND INCREASING THE CHANCES OF A TRULY BRUTAL VARIANT THAT NO VACCINE CAN STOP
DO YOU UNDERSTAND WHAT I AM SAYING?!
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### Author:  [@Heffalump\_and\_Roo](https://boards.straightdope.com/u/Heffalump_and_Roo)
#### Post date: [August 6, 2021, 3:13am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/16 "2021-08-06T03:13:49Z")
Info about effectiveness against the Delta variant from [CDC reference](https://www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/fully-vaccinated-people.html).
> [@](#):
>
> For the Delta variant, recent studies from England and Scotland have noted reduced effectiveness of the Pfizer-BioNTech vaccine against confirmed infection (79%) and symptomatic infection (88%), compared with Alpha (92% and 93%, respectively).(146, 147) During two recent rounds of a national population survey in England when Delta was the dominant stain, 2-dose vaccine effectiveness against PCR-confirmed infection was 72% and 73%, respectively.(155) A study from Canada demonstrated 87% effectiveness against symptomatic illness ≥7 days after receipt of the Pfizer-BioNTech vaccine. (153) [Press releasesexternal icon](https://www.gov.il/en/departments/news/06072021-04) from Israel have noted further decreased effectiveness of vaccines against infection and illness caused by Delta; these differences may in part reflect differences in study methodology, but more technical information is needed to allow full interpretation. Notably, in the United Kingdom, Canada, and Israel, vaccine effectiveness against hospitalization related to Delta was 93%–100% and comparable to that observed with Alpha.(148, 153) Data from the United Kingdom observed that the recent resurgence in COVID-19 cases is being driven by replacement of Alpha with the Delta variant and infections occurring in unvaccinated children and young adults.(155)
So yes, the effectiveness against Delta in the couple studies is less than against Alpha.
In one study, 79% infection and 88% against symptomatic infection.
In another study, 72% and 73% respectively.
They didn’t include the Israel study.
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 3:14am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/17 "2021-08-06T03:14:17Z")
I don’t know why I am apparently one of the few people on this planet with the IQ high enough to understand this. It angers me.
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### Author:  [@DMC](https://boards.straightdope.com/u/DMC)
#### Post date: [August 6, 2021, 3:21am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/18 "2021-08-06T03:21:24Z")
> [@asahi](#):
>
> DO YOU UNDERSTAND WHAT I AM SAYING?!
No, because you’re not saying it loud enough.
Good luck!
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### Author:  [@Heffalump\_and\_Roo](https://boards.straightdope.com/u/Heffalump_and_Roo)
#### Post date: [August 6, 2021, 3:22am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/19 "2021-08-06T03:22:36Z")
> [@DMC](#):
>
> A more sober discussion about the different studies around efficacy of every vaccine/variant combination out there would probably fly as well, but only if it stays toned down a bit
Just a quick note about efficacy and effectiveness so people don’t get confused.
[From WHO](https://www.who.int/news-room/feature-stories/detail/vaccine-efficacy-effectiveness-and-protection)
[ ](https://www.who.int/images/default-source/health-topics/coronavirus/who-topic-12_efficacy-vs-effectiveness.jpg?Status=Master&sfvrsn=4ff45f33_7)
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### Author:  [@asahi](https://boards.straightdope.com/u/asahi)
#### Post date: [August 6, 2021, 3:32am UTC](https://boards.straightdope.com/t/covid-vaccine-effectiveness-rate-including-against-variants/948133/20 "2021-08-06T03:32:01Z")
I am unpopular because people want to believe that “It will all work out.” I don’t live in that world. My world is the real one. It was the same experience on the Mueller/Trump threads.
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