Vaccines

Are the CDC's flu VE studies case-control studies?

Pretty much (for your purposes, anyway).

Do case-control studies provide inferior quality of evidence to RCT's and cohort studies?

It depends. In some cases they are able to provide better information than RCT's and cohort studies. All three kinds of studies are used to look at the influenza vaccines, and the choice depends upon the question being asked.

Doesn't the CDC's case-control study rely on the key assumption that the vaccinated population is not more likely to visit a doctor for influenza-like-illness (ILI) than the unvaccinated population?

If this assumption is incorrect, couldn't the CDC's case-control study falsely show high VE even if it is basically only the vaccinated population getting sick with flu and ILI?

No, odds ratios don't depend on the underlying incidence - they can be calculated using selected samples (one of their advantages).

What side effects are commonly listed for the flu vaccines?

Are headaches, muscle aches, fever, cough, sinus, nausea, and vomiting among the commonly listed side-effects of the flu-shots?

Are these side effects also listed as symptoms of the flu?

Doesn't it seem likely that the flu shot side effects might be considered a kind of "Influenza-Like Illness" (ILI)?

Is it likely that some people who received the flu shot subsequently visit the doctor due to the side-effects which are then labeled as ILI?

Wouldn't such a positive correlation between flu vaccine and ILI falsely increase the CDC's reported vaccine effectiveness?

No. This is the trap you can fall in to when you have no experience with clinical medicine. Diagnoses aren't made based on a list of symptoms, but by pattern recognition. The analogy I use is the Mona Lisa. If you've ever seen the Mona Lisa, I can show you some paintings of "woman with a secretive smile" and you can pick her out immediately. But if you haven't ever seen her, I can show you a painting which fits that description and claim that it is her.

Besides, if you read the description of the methodology, those patients within that 2 week window were excluded anyways. 

Isn't it likely that people who receive the flu-shot are more likely to be in high-risk environments (healthcare workers) or psychologically more inclined to see a doctor about ILI symptoms, and wouldn't this add to the positive correlation between vaccinated population and ILI?

No, again, the underlying prevalence of ILI and propensity to seek medical care do not alter the equation.

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Here is an example scenario where being in the vaccinated population makes you 9x more likely to have the flu and 24x more likely to have ILI, yet the CDC's study could claim 62.5% VE:
50% of the general population receives the flu vaccine.
20% of the general population gets the flu.
25% of the general population gets ILI.
5% of the vaccinated population doesn’t get flu or ILI.
90% of those with the flu were vaccinated.
96% of those with ILI were vaccinated.
18% of the general population was vaccinated and got the flu.
24% of the general population was vaccinated and got ILI.
2% of the population was unvaccinated and got the flu.
1% of the population was unvaccinated and got ILI.


Then suppose in our CDC case-control study we find numbers that track with the absolute percentages:
EE = 1800
EN = 2400
CE = 200
CN = 100
ES = 4200
CS = 300
EER (flu rate in vaccinated) = .429
CER (flu rate in unvaccinated) = .666
RR = .644
OR = .375

Estimated VE = 1-RR = 35.6%
or
Estimated VE = 1-OR = 62.5%

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I'm not sure what you were going for with this.

Can an educated decision about flu vaccine risks vs benefits be made if the benefits are unknown?

Doubtful. That's why research and surveillance are done on risks and benefits.

Isn't it true VE is not the only statistic needed to gauge flu vaccine benefit?

Yes. That's why there are many different studies done to gauge benefit (and risk).  

Does pro-vaccine propaganda and advertisement make anyone aware that VE % alone means nothing?

I don't know. People seem to follow the advice of their physician and public health advisors, which makes the point moot, I suspect. 

Wouldn't we need to know the risk of getting the flu while unvaccinated in order for VE to provide a meaningful measure of benefit?

I'm not sure what you're getting at here. Are you asking if we need measurement of baseline risk in various populations? Again, VE doesn't depend on incidence or risk.

Wouldn't we also need to know how severe the symptoms are likely to be if we do get the flu?

Does anyone know for their specific population profile what is the unvaccinated probability of getting the flu with symptoms more severe than the vaccine side-effects?

That's the point of the research which answers those questions.

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Why do hospitals punish vaccine exempt employees by making them wear masks all day every day?

Is it to use social ostracism to encourage compliance so that the hospital can acquire grant money, avoid liability, and improve the hospital's score on various healthcare rating websites?

Or do hospitals force their vaccine exempt employees to wear masks out of concern for their patients as they claim?

If it is purely to protect patients, why don't these same hospitals make any employee who has cold or flu symptoms wear a mask all day every day?

Isn't the risk to a patient greater from someone who is symptomatic and vaccinated than from someone who is asymptomatic and unvaccinated?

Is it fair that a healthy unvaccinated employee must wear a mask all day every day even in non-patient areas while a vaccinated employee may spew spittle and mucus all over the damned place without being forced to wear a mask?

This sounds like a pet peeve for you?

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Is the whole flu-vaccine business a pharmaceutical industry profit-generating scheme and eugenics conspiracy?

Are you a shill for the pharmaceutical industry?

This seems to belong in the conspiracy part of the forum.

Linda

Can you quantify the unvaccinated risk?

Can you quantify the vaccinated risk?

Can you quantify the risk of vaccine side-effects?

In the 1918 "Spanish" flu pandemic did more people die from the flu or bacterial super-infections?

What role did environmental factors and WWI play in that pandemic?

What role did mass vaccination campaigns and contaminated vaccines play in that pandemic?

All irrelevant questions. The risk of pandemic is just as real and likely today as it was in 1918. By all means don't get vaccinated, however you should not spread such nonsense anti vaccination is the  wiser choice - it's not.

Linda and Paul are making too much sense...careful everyone...this is the kind of stuff that used to get people banned on the old forum!

Hmmm...considering the discussion going on in the Forum section, you might be right about that.

Linda

Pretty much (for your purposes, anyway).


It depends. In some cases they are able to provide better information than RCT's and cohort studies. All three kinds of studies are used to look at the influenza vaccines, and the choice depends upon the question being asked.


No, odds ratios don't depend on the underlying incidence - they can be calculated using selected samples (one of their advantages).


No. This is the trap you can fall in to when you have no experience with clinical medicine. Diagnoses aren't made based on a list of symptoms, but by pattern recognition. The analogy I use is the Mona Lisa. If you've ever seen the Mona Lisa, I can show you some paintings of "woman with a secretive smile" and you can pick her out immediately. But if you haven't ever seen her, I can show you a painting which fits that description and claim that it is her.

Besides, if you read the description of the methodology, those patients within that 2 week window were excluded anyways. 


No, again, the underlying prevalence of ILI and propensity to seek medical care do not alter the equation.


I'm not sure what you were going for with this.

Doubtful. That's why research and surveillance are done on risks and benefits.

Yes. That's why there are many different studies done to gauge benefit (and risk).  

I don't know. People seem to follow the advice of their physician and public health advisors, which makes the point moot, I suspect. 

I'm not sure what you're getting at here. Are you asking if we need measurement of baseline risk in various populations? Again, VE doesn't depend on incidence or risk.



That's the point of the research which answers those questions.

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This sounds like a pet peeve for you?

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This seems to belong in the conspiracy part of the forum.

Linda

You just stated that a correlation between flu vaccine and ILI wouldn’t falsely drive up the VE. This proves you are totally full of shit and have no clue what you’re talking about.

[Laird]

Hmmm...considering the discussion going on in the Forum section, you might be right about that.

Linda

I'm curious to know what you mean by this, and to which discussion you're referring.

Once again I must state my disapproval of this thread being hidden from view like some homeless person being driven from city centres to make it 'presentable'.

Just watch Vaxxed, warts and all, Wakefield might be a fraud and a scoundrel for all I know. The documentary shows enough good reasons for all of us to be worried, conspiracy theorist or skeptic's alike! The CDC doesn't come out of it well.

We're spiralling out of control, and such censorship is speeding up the decline.

[Laird]

Once again I must state my disapproval of this thread being hidden from view like some homeless person being driven from city centres to make it 'presentable'.

Steve, please then contribute to Chris's thread, and do what I've just asked Linda to do: suggest which forum you think this thread belongs in and how the guidelines for science-related threads and/or their interpretation be changed to that effect.

Steve, please then contribute to Chris's thread, and do what I've just asked Linda to do: suggest which forum you think this thread belongs in and how the guidelines for science-related threads and/or their interpretation be changed to that effect.

It was fine where it was.

Which thread by Chris?

[Laird]

It was fine where it was.

OK, then it seems that in your view the guidelines need to be revised, because according to them, it's not fine where it was. If you want to suggest how you'd like to see them revised, then that would be great.

Which thread by Chris?

The one you've already responded in: Site organisation and "view posts" lists.

I'm curious to know what you mean by this, and to which discussion you're referring.

What she refers to is the tactic implemented at Skeptiko against the self named "Banned of 7" We were only allowed to post on two sub-forums. Dissention from the party line was frowned upon at best barely tolerated. This tooķ place before when Alex changed to the newer Skeptiko site. Just recently during the near collapse of said forum Alex categorized those two forums  I believe as the dark underbelly. He often categorized people whom didn't see the light as "stuck on stupid"