Flu Shots

[Skeptic Ginger]

Why some of you think influenza is no big deal when it kills thousands and thousands of people every year is beyond me.

Why do you suppose the WHO has an entire department dedicated to influenza?

WHO Global Influenza Programme

And why do so many countries invest so much of their public health resources toward this infection?

National Influenza Centers



WHO Influenza Overview

Influenza rapidly spreads around the world in seasonal epidemics and imposes a considerable economic burden in the form of hospital and other health care costs and lost productivity.

In annual influenza epidemics 5-15% of the population are affected with upper respiratory tract infections. Hospitalization and deaths mainly occur in high-risk groups (elderly, chronically ill). Although difficult to assess, these annual epidemics are thought to result in between three and five million cases of severe illness and between 250 000 and 500 000 deaths every year around the world. Most deaths currently associated with influenza in industrialized countries occur among the elderly over 65 years of age.

Who cares about a bunch of old geezers anyway?

Much less is known about the impact of influenza in the developing world. However, influenza outbreaks in the tropics where viral transmission normally continues year-round tend to have high attack and case-fatality rates. For example, during an influenza outbreak in Madagascar in 2002, more than 27 000 cases were reported within three months and 800 deaths occurred despite rapid intervention. An investigation of this outbreak, coordinated by the World Health Organization (WHO), found that there were severe health consequences in poorly nourished populations with limited access to adequate health care (see "Outbreak of influenza, Madagascar, July-August 2002," Weekly Epidemiological Record). It is not possible to extrapolate the exact annual burden of influenza in the tropics from data from such occasional and severe outbreaks.

And all these people are malnourished, living in squalor, and their loss has little impact on the rest of the world.

Vaccination is the principal measure for preventing influenza and reducing the impact of epidemics. Various types of influenza vaccines have been available and used for more than 60 years. They are safe and effective in preventing both mild and severe outcomes of influenza (see WHO position paper, “Influenza vaccines”, Weekly Epidemiological Record).

It is recommended that elderly persons, and persons of any age who are considered at “high risk” for influenza-related complications due to underlying health conditions, should be vaccinated. Among the elderly, vaccination is thought to reduce influenza-related morbidity by 60% and influenza-related mortality by 70-80%. Among healthy adults the vaccine is very effective (70-90%) in terms of reducing influenza morbidity, and vaccination has been shown to have substantial health-related and economic benefits in this age group.

I suppose that last little bit is a big lie generated by vaccine manufacturers and sucked up by the corrupt government public health organizations which in turn dupe the majority of health care providers. Of course such fine young educated persons as yourselves have taken the time to conduct your own scientific research and you are too wise to be duped like those of us with university degrees and years of experience. We providers have naturally lost all objectivity in our fields despite how much we have also taken the time to absorb all the information we can.



WHO position on influenza vaccines

Although influenza vaccination is increasing throughout the world, especially in many middle-income countries of Latin America and central and eastern Europe, no country fully implements its vaccine recommendations. Even in wealthy industrialized countries, significant proportions of the groups at risk of complications from influenza are not vaccinated.

WHO strongly emphasizes the importance of raising the public consciousness of influenza and its complications as well as of the beneficial effects of influenza vaccination. There is a growing awareness of the considerable influenza morbidity among schoolchildren and the often severe clinical course of influenza in the youngest age groups. Children are also playing a crucial role in the transmission of the infection. Furthermore, significant herd immunity effects have been observed in non-immunized segments of the population following immunization of children in Japan, the Russian Federation and the United States. Therefore, further exploration of the safety and cost–effectiveness of introducing influenza vaccination into national immunization programmes is clearly warranted.

This position statement according to the antivax position expressed by members in this thread indicates pure corruption and not an ounce of expertise. No researchers and public health professionals dedicated to their work remain at the WHO. In fact, no researchers and public health professionals even exist anymore. They are all ignorant dupes, so say Ivor, robinson and kellyb, those great intellects of the JREF forum.

 

[Skeptic Ginger]

The antivaxers have latched on to this, "better nutrition and sanitation eliminated infection fatalities, not vaccines", lie and continue to promote it despite the fact it has been thoroughly debunked. It only takes a cursory view of the disease elimination curves when individual vaccines were introduced to see the correlation is with vaccine introduction, not nutrition and sanitation. I suppose if you weren't alive in the 50s it's easy to imagine we were all drinking gutter water and suffering from malnutrition.

 

[Professor Yaffle]

That's a classic symptom of pertussis (whooping cough), not influenza.

Specificity is 45%-84% according to this article meaning posttussive vomiting is diagnostic for pertussis 45%-84% of the time.

(Going completely off topic for a moment) I vomit from coughing pretty much every time I have a really bad cold that goes to my chest. But I think that is a combination of asthma and a very strong gag reflex. Strangely, the vomiting actually relieves the coughing for a short while. I was undiagnosed for quite a lng time as a child, and in order to get any relief with the cough medicines the doctors kept telling me to take, I had to take the vilest expectorant known to man, whih would make me sick so that I would feel better for a short time.

 

[Professor Yaffle]

Just a question about specificity (its a long time since I learned any of this). In the example you gave above, would rates of pertussis affect the specificity of the symptom? For example, if pertussis is rife, there would be a high specificity because so many people would have it, there would be proportionally fewer false negatives. If pertussis is all but wiped out, nearly all cases of psosttussive vomitting would be due to something else - ie false positives, so specificity would be low. Have I got that right? If so, what background level of pertussis is the figure you gave based on? Is it based on a community with high vaccination rates (I could only get the astract so I couldn't read it all).

I'm not actually going anywhere, or trying to make a point with this, I am just interested.

 

[fls]

Just a question about specificity (its a long time since I learned any of this). In the example you gave above, would rates of pertussis affect the specificity of the symptom?

No, but you're on the right track. Rates don't affect sensitivity and specificity or likelihood ratios. The specificity tells you, of all the people who don't have pertussis, how many don't have pertussive vomitting.

But rates do affect positive predictive value and negative predictive value. And that is what you are asking in your paragraph below. "What portion of people with pertussive vomitting have pertussis?" And rates are used with likelihood ratios to determine the probability of pertussis, given that you have pertussive vomitting.

For example, if pertussis is rife, there would be a high specificity because so many people would have it, there would be proportionally fewer false negatives. If pertussis is all but wiped out, nearly all cases of psosttussive vomitting would be due to something else - ie false positives, so specificity would be low. Have I got that right? If so, what background level of pertussis is the figure you gave based on? Is it based on a community with high vaccination rates (I could only get the astract so I couldn't read it all).

I'm not actually going anywhere, or trying to make a point with this, I am just interested.

The LR in the chart is 2.2, so it would double your odds of having pertussis. For example, if the background rate is 0.1%, your odds of having pertussis are 0.002 to 1. If the background rate is 10%, your odds of having pertussis are 0.2 to 1.

Linda

 

[Professor Yaffle]

Thanks Linda, That's what I thought specificity meant (I read a good article on the subject by Ben Goldacre a while back about sensitivity, specificity, positive predictive value etc), but I became a little confused by Skeptigirl's mention of it and thought I had remembered wrongly. Must have misunderstood what she was saying.

Edit - here's the article I mentioned: http://www.badscience.net/2006/12/crystal-balls-and-positive-predictive-values/

 

[Ivor the Engineer]

<snip>

WHO position on influenza vaccines

This position statement according to the antivax position expressed by members in this thread indicates pure corruption and not an ounce of expertise. No researchers and public health professionals dedicated to their work remain at the WHO. In fact, no researchers and public health professionals even exist anymore. They are all ignorant dupes, so say Ivor, robinson and kellyb, those great intellects of the JREF forum.

It's so much easier to discredit your opponents when you misrepresent their position.

It appears to be reasonable to spend money on vaccinating at-risk groups, such as those below 5, those above 65 years old and HCW's.

It is only reasonable to recommend spending money vaccinating everyone if you want to ensure there is enough manufacturing capacity to produce a vaccine for large numbers of people in a short period of time, as would be required for a flu pandemic.

BTW, thank you for the complement.

 

[Dymanic]

It appears to be reasonable to spend money on vaccinating at-risk groups, such as those below 5, those above 65 years old and HCW's.

It is only reasonable to recommend spending money vaccinating everyone if you want to ensure there is enough manufacturing capacity to produce a vaccine for large numbers of people in a short period of time, as would be required for a flu pandemic.

Even if the only payoff you were looking for in vaccinating large numbers of people was avoiding deaths and hospitalizations in at-risk groups, you might still consider trying to increase coverage to the point where you could protect more of them through herd immunity. If what you were looking at was the money, you might take a different approach, looking at the estimated number of productive hours saved per dose. And if you considered neither of those, you might still want to give some thought to the special circumstance the pandemic prospect represents. There is something admittedly distasteful about the idea of encouraging the ramping up of manufacturing capacities as a hedge against the pandemic threat by promoting seasonal vaccines, but I don't see much willingness to prop up the effort with public money. What other alternatives do you see?

 

[Ivor the Engineer]

Even if the only payoff you were looking for in vaccinating large numbers of people was avoiding deaths and hospitalizations in at-risk groups, you might still consider trying to increase coverage to the point where you could protect more of them through herd immunity.

Yes, that is why HCW's and carers are given the flu jab in the UK. I've already said if I was often around people who are classed as an at-risk group I'd get a flu shot and encourage them to get one too.

If what you were looking at was the money, you might take a different approach, looking at the estimated number of productive hours saved per dose.

Yet most companies don't offer to pay for their employees to have the flu jab.

And if you considered neither of those, you might still want to give some thought to the special circumstance the pandemic prospect represents. There is something admittedly distasteful about the idea of encouraging the ramping up of manufacturing capacities as a hedge against the pandemic threat by promoting seasonal vaccines, but I don't see much willingness to prop up the effort with public money. What other alternatives do you see?

I know it's a radical concept, but what about telling people the truth?

 

[Dymanic]

I know it's a radical concept, but what about telling people the truth?

The Truth -- as recognized by the vast majority of virologists, epidemiologists, physicians, and public health care officials -- is that the most effective means of preventing serious illness as well as lost productive time due to influenza is through vaccination. Increasing coverage has a bonus, that being greater incentive for vaccine manufactures to increase production capacities, and that truth has been told as well -- but it would be a pretty rare individual who would take that into consideration when deciding whether or not to seek vaccination, so placing a lot of emphasis on it wouldn't make much sense. Physicians continue to recommend the flu vax for individual patients because they recognize it as in the best interests of the individual patient, and public health care officials continue to promote the practice because they recognize it as being in the best interests of large numbers of people taken together. Pharmaceutical companies (some of them) continue to produce flu vaccine because they find it to be in their own interests to do so, and The Truth is that they aren't going to do it for any other reason. If governments and the people they represent do not consider the pandemic threat serious enough to justify sinking money into response measures, it's hardly realistic to expect companies to lose money picking up the slack.

 

[Skeptic Ginger]

Thanks Linda, That's what I thought specificity meant (I read a good article on the subject by Ben Goldacre a while back about sensitivity, specificity, positive predictive value etc), but I became a little confused by Skeptigirl's mention of it and thought I had remembered wrongly. Must have misunderstood what she was saying.

Edit - here's the article I mentioned: http://www.badscience.net/2006/12/crystal-balls-and-positive-predictive-values/

Well I understand the same thing as Linda as far as predictive value so it appears my over simplified and mostly hasty version of specificity was the problem.

Here's the simple way I remember the interpretation:

Specificity - the 'p' is my mnemonic for positive - refers to the percentage of people you would erroneously include who tested positive but didn't have the condition.

Sensitivity - the 'n' is my mnemonic for negative - refers to how many people you would miss because of falsely negative tests.

 

[Ivor the Engineer]

The Truth -- as recognized by the vast majority of virologists, epidemiologists, physicians, and public health care officials -- is that the most effective means of preventing serious illness as well as lost productive time due to influenza is through vaccination.

It's just that the flu vaccine does not appear to be very effective at preventing serious illness, or reducing lost productive time.

Increasing coverage has a bonus, that being greater incentive for vaccine manufactures to increase production capacities, and that truth has been told as well -- but it would be a pretty rare individual who would take that into consideration when deciding whether or not to seek vaccination, so placing a lot of emphasis on it wouldn't make much sense.

It would be the only reason I would consider getting a flu jab this year.

Physicians continue to recommend the flu vax for individual patients because they recognize it as in the best interests of the individual patient, and public health care officials continue to promote the practice because they recognize it as being in the best interests of large numbers of people taken together.

Well they have to be seen to be doing something don't they? I'm sure most like to think they are making a significant difference, even if the evidence indicates otherwise.

Pharmaceutical companies (some of them) continue to produce flu vaccine because they find it to be in their own interests to do so, and The Truth is that they aren't going to do it for any other reason. If governments and the people they represent do not consider the pandemic threat serious enough to justify sinking money into response measures, it's hardly realistic to expect companies to lose money picking up the slack.

Most governments with a rational policy appear to offer the flu jab to those most at risk from serious complications (and their immediate contacts), for what good it will do them.

This page from the CDC is funny:

The page says this...

Annual vaccination against influenza is recommended for:

all persons, including school-aged children, who want to reduce the risk of becoming ill with influenza or of transmitting influenza to others;
all children aged 6–59 months (i.e., 6 months–4 years);
all persons aged 50 years and older;
children and adolescents (aged 6 months–18 years) receiving long-term aspirin therapy who therefore might be at risk for experiencing Reye syndrome after influenza virus infection;
women who will be pregnant during the influenza season;
adults and children who have chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, hematological or metabolic disorders (including diabetes mellitus);
adults and children who have immunosuppression (including immunosuppression caused by medications or by human immunodeficiency virus;
adults and children who have any condition (e.g., cognitive dysfunction, spinal cord injuries, seizure disorders, or other neuromuscular disorders) that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk for aspiration;
residents of nursing homes and other chronic-care facilities;
health-care personnel;
healthy household contacts (including children) and caregivers of children aged <5 years and adults aged 50 years and older, with particular emphasis on vaccinating contacts of children aged <6 months; and
healthy household contacts (including children) and caregivers of persons with medical conditions that put them at higher risk for severe complications from influenza.

...but means:

Annual vaccination against influenza is recommended for:

all persons, except those who would be harmed by getting it.

So why bother with all the bollocks pretending to target particular groups?

 

[Skeptic Ginger]

Your claims the flu vaccine lacks effectiveness is based on research which has been discredited by more specific and careful studies.

 

[Dymanic]

It's just that the flu vaccine does not appear to be very effective at preventing serious illness, or reducing lost productive time.

In other words, your rhetorical question: "what about telling people the truth?" really means: "what about telling people the truth as I see it, rather than as they see it?"

It would be the only reason I would consider getting a flu jab this year.

That would surely place you in a very small percentage of individuals as far as that decision is concerned.

Well they have to be seen to be doing something don't they? I'm sure most like to think they are making a significant difference, even if the evidence indicates otherwise.

Which is it? Validation seekers, or simple minds / noble hearts? Are you sure you don't want to just go with "evil conspirators"?

Most governments with a rational policy appear to offer the flu jab to those most at risk from serious complications (and their immediate contacts), for what good it will do them.

It's nice to see that you acknowledge that this is a rational policy, even if you do immediately turn around and contradict yourself by implying that it does no good.

 

[Acleron]

I know it's a radical concept, but what about telling people the truth?

But you complained that the truth was scare tactics.

 

[Ivor the Engineer]

In other words, your rhetorical question: "what about telling people the truth?" really means: "what about telling people the truth as I see it, rather than as they see it?"

The truth would include a balanced appraisal of the evidence, as was provided to my mother by her GP.

That would surely place you in a very small percentage of individuals as far as that decision is concerned.

Possibly.

Which is it? Validation seekers, or simple minds / noble hearts? Are you sure you don't want to just go with "evil conspirators"?

Can I mix and match? I'm going for validation seekers with noble hearts for the most part, with a few evil conspirators sprinkled on the top.

It's nice to see that you acknowledge that this is a rational policy, even if you do immediately turn around and contradict yourself by implying that it does no good.

The flu vaccination provides a variable level of protection against seasonal flu in these groups, ranging from poor to good. It's just that it doesn't stop many of them being admitted to hospital or dying.

 

[T.A.M.]

I am a little late to the party, but as a practicing Family Physician, I would very much like to see this evidence that allegedly proves the flu vaccine:

...does not appear to be very effective at preventing serious illness, or reducing lost productive time.

As Ivor has contended.

From the pov of my own practice, I actively promote the annual influenza vaccine to the following groups:

1. Children 6 months to 2 years
2. All Adults age 65 and over
3. All Health Care Workers
4. All individuals age 2 and older who have chronic illnesses

The rest, we discuss the shot, and if they wish to have one, then I give them one.

TAM

 

[T.A.M.]

That's a classic symptom of pertussis (whooping cough), not influenza.

Specificity is 45%-84% according to this article meaning posttussive vomiting is diagnostic for pertussis 45%-84% of the time.

Looking at the variation (very wide) in the sensitivity and specificity in that article's chart for signs/symptoms associated with pertussis, it tells me that no one symptom is diagnostic.

1. Posttussive nausea and vomiting - common with any cough. The repetitive nature of Whooping Cough is the cause, not the origin of the illness.
2. "Barking" cough - seen in croup, tracheitis, and sometimes just in a good old URTI.
3. cough lasting longer than 2-3 weeks: varies from person to person, infection to infection. I have seen people with a good old "cold" have the couhg for 4-6 weeks after the initial infection. Allergies and Asthma also provide a sustained cough.

TAM

 

[kellyb]

I am a little late to the party, but as a practicing Family Physician, I would very much like to see this evidence that allegedly proves the flu vaccine:



As Ivor has contended.

From the pov of my own practice, I actively promote the annual influenza vaccine to the following groups:

1. Children 6 months to 2 years
2. All Adults age 65 and over
3. All Health Care Workers
4. All individuals age 2 and older who have chronic illnesses

The rest, we discuss the shot, and if they wish to have one, then I give them one.

TAM

Regarding kids under 2:

http://www.bmj.com/cgi/content/full/333/7574/912

In children under 2 years inactivated vaccines had the same field efficacy as placebo,8 and in healthy people under 65 vaccination did not affect hospital stay, time off work, or death from influenza and its complications.

And in adults under age 65:
http://www.cochrane.org/reviews/en/ab001269.html

There is not enough evidence to decide whether routine vaccination to prevent influenza in healthy adults is effective

Main results
Forty-eight reports were included: 38 (57 sub-studies) were clinical trials providing data about effectiveness, efficacy and harms of influenza vaccines and involved 66,248 people; 8 were comparative non-randomised studies and tested the association of the vaccines with serious harms; 2 were reports of harms which could not be introduced in the data analysis.
Inactivated parenteral vaccines were 30% effective (95% CI 17% to 41%) against influenza-like illness, and 80% (95% CI 56% to 91%) efficacious against influenza when the vaccine matched the circulating strain and circulation was high, but decreased to 50% (95% CI 27% to 65%) when it did not. Excluding the studies of the 1968 to 1969 pandemic, effectiveness was 15% (95% CI 9% to 22%) and efficacy was 73% (95% CI 53% to 84%).

 

[robinson]

Studies of the effects on influenza-like illness and its complications most closely replicate real life conditions because no one knows what agent (if any) causes this disease. Influenza-like illness is an acute respiratory disease caused by many different viruses (including influenza A and B), which presents with symptoms and signs that cannot be distinguished from those of influenza. Influenza-like illness does not have documented laboratory isolation of the causative agent and is the syndrome that most commonly presents to doctors ("the flu").

http://www.bmj.com/cgi/content/full/333/7574/912

What in the hell?