This is my last post for some time about flu vaccines, though in retrospect, perhaps this should’ve been my first.
If mass flu vaccines every year are the answer, then just how severe is the flu problem exactly, specifically as it relates to its worst possible outcome, death? We know people die from the flu each year, but how is this data known, confirmed, and compiled to measure the mortality burden the flu imposes on society?
My initial thoughts before researching answers to these questions were as follows: since many illnesses can masquerade or mimic the flu virus, a lab-confirmed test should be performed to confirm a flu infection, and of those lab-confirmed flu infections, death certificates should state flu as the primary cause when tests corroborate a medical autopsy as such. These statistics would then just be confirmed and consolidated from local and state levels into a national figure for a given year. At least, that’s how I think an ideal way to aggregate this data would be more or less performed in order to accurately determine deaths attributed to the flu.
Post 2003, I’ve read anything from 23, 607 (Centers for Disease Control–CDC) to 36,000 (most quoted figure) and 41,400 (National Institute of Allergy and Infectious Diseases–NIAID) for the number of flu-caused deaths per year in the US. But prior to 2003, the CDC used 20,000 as the annual figure of flu deaths. However, the reason for this wide variance is simple: since most US death certificates don’t list the flu as a primary or secondary cause of death and of those that do, even fewer are lab-confirmed for the flu virus, the amount of deaths attributed to the flu each year must be guessed. Different assumptions and even different computer models can yield vastly different estimates.
Also, a peculiar thing to note with the CDC’s annual mortality data from its National Vital Statistics Reports, is that influenza is grouped along with pneumonia, but the overwhelming number of deaths in this “Influenza and Pneumonia” category was from pneumonia instead of the flu (together, the 7th or 8th leading cause of death in the US, depending on year):
The data above is from the 2006 final version of the NVSR. The final versions of these mortality data reports seem to be produced on a 2- or 3- year lag and unlike preliminary versions, details the breakouts of the “Influenza and pneumonia” category. Currently, 2009 is the latest version for finalized data, and going back 12 years to 1998, deaths attributed to influenza by age grouping and year are as follows:
So, grouping the flu with pneumonia (even though the two don’t always correlate) and using different modeling techniques and assumptions over time (instead of measuring more directly), it’s difficult to obtain an accurate, unbiased picture of how severe flu deaths are each year. The CDC doesn’t agree with itself all the time either. And I’m far from the only one to notice these discrepancies.
In 2006, the Journal of American Physicians and Surgeons voiced criticism of the CDC’s methodologies for estimating and classifying flu deaths:
The CDC and news media frequently proclaim that there are about 36,000 influenza-associated deaths annually. Review of the mortality data from the CDC’s National Vital Statistics System(NVSS) reveals these estimates are grossly exaggerated. The NVSS reports preliminary mortality statistics and distinguishes between influenza-related deaths and pneumonia-related mortality. When the final report is issued, influenza mortalities are combined with the far more frequent pneumonia deaths, yielding an exaggerated representation of influenza deaths. Pneumonia related mortality due to immunosuppression, AIDS, malnutrition, and a variety of other predisposing medical conditions is therefore combined with seasonal influenza deaths. The actual influenza related deaths for the years 1997 to 2002 ranged from 257 to 1,765 annually. These values are further overestimated by combining deaths from laboratory-confirmed influenza infections with cases lacking laboratory confirmation.
In the prior year, a review article titled “Are US flu death figures more PR than science?” was published in the British Medical Journal noting similar criticisms:
Meanwhile, according to the CDC’s National Center for Health Statistics (NCHS), “influenza and pneumonia” took 62 034 lives in 2001—61 777 of which were attributed to pneumonia and 257 to flu, and in only 18 cases was flu virus positively identified. Between 1979 and 2002, NCHS data show an average 1348 flu deaths per year (range 257 to 3006)…
William Thompson of the CDC’s National Immunization Program (NIP), and lead author of the CDC’s 2003 JAMA article, explained that “influenza-associated mortality” is “a statistical association between deaths and viral data available.” He said that an association does not imply an underlying cause of death: “Based on modelling, we think it’s associated. I don’t know that we would say that it’s the underlying cause of death.”…
Before 2003 CDC said that 20 000 influenza-associated deaths occurred each year. The new figure of 36 000 reported in the January 2003 JAMA paper is an estimate of influenza-associated mortality over the 1990s. Keiji Fukuda, a flu researcher and a co-author of the paper, has been quoted as offering two possible causes for this 80% increase: “One is that the number of people older than 65 is growing larger…The second possible reason is the type of virus that predominated in the 1990s [was more virulent].”…
If flu is in fact not a major cause of death, this public relations approach is surely exaggerated. Moreover, by arbitrarily linking flu with pneumonia, current data are statistically biased. Until corrected and until unbiased statistics are developed, the chances for sound discussion and public health policy are limited.
None of this is to be misconstrued as denying that people die from the flu or that the flu isn’t a serious issue, only that there are serious methodological issues in how this is defined, classified, and estimated on a large scale since it’s not measured in a direct, straightforward manner.
Also, taken in context with my previous post about how the CDC/FDA/HHS is more of a cheerleader and business partner (with Supreme Court blessing) with vaccine manufacturers than an independent regulator that places public health over private profits, like the media advertising of flu vaccine benefits (my first post about the flu), the magnitude of flu deaths has so far been greatly exaggerated to boost more vaccine sales through fear-mongering rather than cold hard facts and evidence that should guide public health policies.
More efforts should be invested in having better surveillance of flu-caused deaths instead of relying so much on assumptions and indirect guesses that are heavily sensitive to bias in either direction. Lab tests should confirm flu virus infections and there should be more effort to have flu as a primary cause of death in instances where viral lab tests are positive and corroborate a medical professional’s judgment cause of death. This would make deaths attributed to flu more reliable and easy to tally. Also, the flu should be its own mortality classification separate from pneumonia. All of these measures would provide us with a more accurate, consistent, and reliable picture of how big of a burden flu deaths are on society each year and hopefully guide public health policy decisions in a more rational manner.
Final Conclusions at this Time
Before concluding this off-topic series of posts about my own thoughts related to flu vaccines, I thought it’d be interesting to look at the CDC’s Vaccine Adverse Event Reporting Sytem (VAERS) database, more specifically using the query tool from the National Vaccine Information Center’s (NIVC) Medalert (it’s an easier, more intuitive interface).
I was just curious how many different adverse reactions are reported each year just for the flu vaccines for 1998-2009, and here is what I found:
Considering that a typical flu season utilizes about 100 million vaccines, I thought it was pretty impressive that only 46,000 to 76,000 different adverse reactions are reported each year. The 1986 National Childhood Vaccine Injury Act that was discussed in my second post about the flu, requires doctors and vaccine makers to report adverse reactions, but the NVIC estimates compliance with this requirement to be between 1% and 10% in any year. Outside of it being part of the law, I’m unclear what the penalties, if any, there are for non-compliance. But if we take the NVIC’s estimate seriously, that means the average number of adverse reaction reports where at least the flu vaccine is implicated over this 12 year period (64,437) is probably an under-estimation of the adverse reactions.
I also noticed that the 2001 CDC figure for flu deaths (257) didn’t seem to cohere well with the corresponding VAERS death records (432). Given that the 257 is an indirect guess and VAERS records can be submitted by anyone (though mostly it seems to be some type of medical professional), it’s hard to make perfect sense of these data sets.
1. The magnitude of flu-caused deaths in the US seems to be relatively small according to the CDC’s own data and greatly exaggerated (and inconsistently over-estimated and confusedly classified) as well;
2. The benefits of flu vaccines are also greatly exaggerated in the media compared to the results of independent, controlled studies; and
3. The number of adverse reactions in context of the number of flu vaccines given in an average flu season is also small by comparison.
How did such molehills become towering mountains?