December 04, 2018
The CDC Claims the Flu Shot Reduces Mortality in the Elderly. But Where’s the Evidence?
The US Centers for Disease Control and Prevention (CDC) recommends that everyone aged six months and up, including pregnant women, get an annual influenza vaccine. The two fundamental assumptions underlying the CDC’s policy are that vaccination reduces transmission of the virus and reduces the risk of potentially deadly complications. Yet multiple reviews of the scientific literature have concluded that there is no good scientific evidence to support the CDC’s claims.
Notwithstanding the science, to increase demand for the pharmaceutical companies’ influenza vaccine products, the CDC makes use of fear marketing, asserting as fact that tens of thousands of people die each year from the flu, even though the CDC’s numbers are actually estimates that are controversial because they are based on dubious assumptions that appear to result in a great overestimation of the negative impact of influenza on societal health.
The primary justification for the CDC’s flu vaccine policy is the assumption that it significantly reduces the mortality rate among people aged 65 and older, the group at highest risk of potentially deadly complications from the flu. The CDC declares to the public that the vaccine does so as though this was a scientifically proven fact. Yet, the reality is that the CDC’s bold claim that the vaccine greatly reduces the risk of death among the elderly has been thoroughly discredited by the scientific community.
…
contrary to the CDC’s claims of a great beneficial effect on mortality,
influenza mortality and hospitalization rates for older Americans
significantly increased in the 80s and 90s, during the same time that
influenza vaccination rates for elderly Americans dramatically
increased.
The Implausibility of the CDC’s Claims
Concerns about the CDC’s mortality claim were raised by researchers from the National Institutes of Health (NIH) in a study published in April 2005 in Archives of Internal Medicine (now JAMA Internal Medicine). Their concern was prompted by the observation that, despite a considerable increase in vaccination coverage among people aged 65 or older—from at most 20 percent before 1980 to 65 percent in 2001—pneumonia and influenza mortality rates had actually substantially risen.That is to say, to quote a review published in Virology Journal in 2008, contrary to the CDC’s claims of a great beneficial effect on mortality, “influenza mortality and hospitalization rates for older Americans significantly increased in the 80s and 90s, during the same time that influenza vaccination rates for elderly Americans dramatically increased.” (Emphasis added.)
As the authors of the 2005 NIH study commented, this result was “surprising” since vaccination was supposed to be “highly effective at reducing influenza-related mortality”—an assumption underlying CDC policy that “has never been studied in clinical trials”.
Relying instead on post-marketing observational studies of the general population, the CDC has claimed that vaccine efficacy in preventing influenza-related deaths is as high as 80 percent.
Furthermore, to support its claim of an enormous benefit, the CDC has relied on a meta-analysis of observational studies that concluded that vaccination reduces the number of flu-season deaths from any cause among the elderly “by an astonishing 50%.”
In their own study, however, the NIH researchers found that, over the course of thirty-three flu seasons, influenza-related deaths were on average only about 5 percent and “always less than 10% of the total number of winter deaths among the elderly.”
The obvious question was: How could it be possible for the influenza vaccine to reduce by half deaths during winter from any cause when no more than one-tenth of deaths in any given flu season could be attributed to influenza?
The most obvious answer was that it couldn’t, and so the researchers examined more closely the methodology of the observational studies that the CDC was relying upon. The conclusion they drew from doing so was that the CDC’s implausible numbers were due to a systemic bias in those studies. There was a “disparity among vaccination” in these studies between cohorts that received a flu vaccine and those that didn’t.
Specifically, it wasn’t that vaccinated individuals were less likely to die, but that sick elderly people whose frail condition made them more likely to die during the coming flu season were less likely to get a flu shot.
Faced with this identification of a systemic bias in their methodology and despite the obvious implausibility of its own claims, the CDC’s response was to question the methodology of the NIH researchers’ study while reiterating its unshaken faith in the studies it was relying upon to promote the flu vaccine.
Notwithstanding the lack of science to support the statement, and no doubt prompted by the need for government agencies to show solidarity on public vaccine policy, the CDC and NIH subsequently published a joint statement claiming that the seasonal flu shot was the best way to protect old people from dying.
The
sharp decline in influenza-related deaths among people aged 65 to 74
years in the years immediately after A(H3N2) viruses emerged in the 1968
pandemic was most likely due to the acquisition of natural immunity to
these viruses.
“The sharp decline in influenza-related deaths among people aged 65 to 74 years in the years immediately after A(H3N2) viruses emerged in the 1968 pandemic was most likely due to the acquisition of natural immunity to these viruses. Because of this strong natural immunization effect, by 1980, relatively few deaths in this age group (about 5000 per year) were left to prevent. We found a similar pattern in influenza-related mortality rates among persons aged 45 to 64 years, an age group with substantially lower vaccine coverage. Together with the flat excess mortality rates after 1980, this suggests that influenza vaccination of persons aged 45 to 74 years provided little or no mortality benefit beyond natural immunization acquired during the first decade of emergence of the A(H3N2) virus.”The way the NIH’s joint statement with the CDC contrasted with its own research findings is a remarkable illustration of the institutionalized cognitive dissonance that exists when it comes to public vaccine policy.
The CDC’s Mortality Claims Further Debunked
Numerous additional studies have since been published highlighting the lack of credibility of the CDC’s claims about the vaccine’s effectiveness. A systematic review published in The Lancet in October 2005 found a “modest” effect of the vaccine on mortality, but its authors—which included lead author Tom Jefferson, a top researcher for the Cochrane Collaboration—cautioned that this finding must be interpreted in light of the apparent systemic bias of the observational studies. They likewise attributed the perceived effect of the vaccine to a difference in vaccination rates among the cohorts “and the resulting selection bias”.Randomized controlled trials could minimize any such bias, they observed, but the evidence from such studies was “scant and badly reported.” Hence, placebo-controlled trials were needed to “clarify the effects of influenza vaccines in individuals”. The problem was that such studies were considered impossible “on ethical grounds” due to the fact that mass vaccination was already recommended as a matter of public policy.
In other words, the science wasn’t done before the CDC made its universal vaccination recommendation, and now they refuse to do the science on the grounds that government technocrats have already made up their minds that everyone aged six months and up should get an annual flu shot.
The lead author of the 2005 NIH study, Lone Simonsen, was also coauthor with W. Paul Glezen of a commentary in the International Journal of Epidemiology in 2006 that reiterated the problems with the CDC’s claims. Although the vaccination rate for elderly people had increased by as much as 67 percent from 1989 to 1997, there was no evidence that vaccination reduced hospitalizations or deaths. On the contrary, “mortality and hospitalization rates continued to increase rather than decline”. The studies the CDC cited to support its claim of a dramatic reduction in mortality suffered from a selection bias that resulted in “substantial overestimation of vaccine benefits.”
A study in the International Journal of Epidemiology also published in 2006 confirmed the systemic selection bias of the observational studies. Its authors concluded that not only had the results of those studies indicated “preferential receipt of vaccine by relatively healthy seniors”, but that the magnitude of this demonstrated bias “was sufficient to account entirely for the associations observed”. (Emphasis added.)
Not
only is the evidence supporting the safety and effectiveness of
influenza vaccination lacking, but there are also reasons to doubt
conventional estimates of the mortality burden of influenza.
Furthermore, “influenza vaccines impose their own particular burden—to the tune of billions of dollars annually.”
Indeed, the very high cost of yearly vaccination for large parts of the population was among the considerations of a 2014 Cochrane meta-analysis that concluded that the results of a systematic review of existing studies “provide no evidence for the utilization of vaccination against influenza in healthy adults as a routine public health measure.”
A randomized controlled trial studying the cost effectiveness of influenza vaccination in healthy adults under aged 65 and published in JAMA in 2000 found that this practice “is unlikely to provide societal economic benefit in most years”—when, according to their data, it generated greater costs than to not vaccinate.
Peter Doshi followed up in 2013 with another BMJ commentary. After all those years, the CDC was still sticking to its claims. And yet, if the CDC’s claims were true, it would mean “that influenza vaccines can save more lives than any other single licensed medicine on the planet. Perhaps there is a reason CDC does not shout this from the rooftop: it’s too good to be true. Since at least 2005, non-CDC researchers have pointed out the seeming impossibility that influenza vaccines could be preventing 50% of all deaths from all causes when influenza is estimated to only cause around 5% of all wintertime deaths.”
Despite scientists pointing out the “healthy user bias” inherent in the observational studies that the CDC relied on to support its bold claims, “CDC does not rebut or in any other way respond to these criticisms.”
“If the observational studies cannot be trusted,” Doshi asked, “what evidence is there that influenza vaccines reduce deaths of older people—the reason the policy was originally created? Virtually none…. This means that influenza vaccines are approved for use in older people despite any clinical trials demonstrating a reduction in serious outcomes.” (Emphasis added.)
“Perhaps most perplexing,” Doshi added, “is officials’ lack of interest in the absence of good quality evidence.”
He further observed how government agencies promote the flu shot by claiming it’s been proven safe. He cited the example of a YouTube video produced by the NIH in which the director of the US National Institute of Allergy and Infectious Diseases, Anthony Fauci, declared that it was “very, very, very rare” for a serious adverse event to be associated with the influenza vaccine.
Yet, “Months later, Australia suspended its influenza vaccination program in under five year olds after many (one in every 110 vaccinated) children had febrile convulsions after vaccination. Another serious reaction to influenza vaccines—and also unexpected—occurred in Sweden and Finland, where H1N1 influenza vaccines were associated with a spike in cases of narcolepsy among adolescents (about one in every 55,000 vaccinated). Subsequent investigations by governmental and non-governmental researchers confirmed the vaccine’s role in these serious events.”
The NIH’s presenter in the video, Anthony Fauci, also happened to be among the opponents of conducting randomized, placebo-controlled studies to determine the safety of the influenza vaccine. “The reason? Placebo recipients would be deprived of influenza vaccines—that is, the standard of care, thanks to CDC guidelines.”
“Drug companies”, Doshi continued, “have long known that to sell some products, you would have to first sell people on the disease.” Only, in the case of the influenza vaccine, “the salesmen are public health officials”.
Safe and effective, safe and effective, safe and effective. Not.
ReplyDelete