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New evidence, same conclusion: Tamiflu only modestly useful for influenza

Tamiflu

Does Tamiflu have any meaningful effects on the prevention or treatment of influenza? Considering the drug’s been on the market for almost 15 years, and is widely used, you should expect this question has been answered after 15 flu seasons. Answering this question from a science-based perspective requires three steps: Consider prior probability, be systematic in the approach, and get all the data. It’s the third step that’s been (until now) impossible with Tamiflu: Some data was unpublished. In general, there’s good evidence to show that negative studies are less likely to be published than positive studies. Unless unpublished studies are included, systematic reviews are more likely to miss negative data, which means there’s the risk of bias in favor of an intervention.

The absence of a full data set on Tamiflu (oseltamivir) and the other neuraminidase inhibitor Relenza (zanamivir) became a rallying point for BMJ and the AllTrials campaign, which seeks to enhance the transparency and accessibility of clinical trials data by challenging trial investigators to make all evidence freely available. (Reforming and enhancing access to trial data was one of the most essential changes recommended by Ben Goldacre in his book, Bad Pharma.) In 2009, Tamiflu’s manufacturer, Hoffman-La Roche committed to making the Tamiflu data set available to investigators. Now after four years of back-and-forth between BMJ, investigators, and Roche, the full clinical trials data set has been made freely available. An updated systematic review was published today in BMJ (formerly The British Medical Journal), entitled “Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments.” This will be a short post covering the highlights. As the entire study and accompanying data are freely available, I’ll await continued discussion in the comments. (more…)

Posted in: Clinical Trials, Pharmaceuticals, Public Health

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False “balance” on influenza with an appeal to nature

One of the encouraging shifts I’ve seen in health journalism over the past few years is the growing recognition that antivaccine sentiment is antiscientific at its core, and doesn’t justify false “balance” in the media. There’s no reason to give credibility to the antivaccine argument when their positions are built on a selection of discredited and debunked tropes. This move away from false balance and towards a more accurate reflection of the evidence seems to have started with the decline and disgrace of Andrew Wakefield and his MMR fraud. And there is now no question that antivaccine sentiment has a body count: Simply look at the resurgence of preventable communicable disease. Today, antivaccinationists are increasingly recognized for what they are – threats to public health. It seems less common today (versus just 5 years ago) that strident antivaccine voices are given either air time or credibility in the media.

But false balance on topics like influenza can occur without giving a voice to groups like antivaccinationists. A more subtle technique to shift perceptions is both widespread and hard to detect, unless you’re aware of it: the naturalistic fallacy, known more accurately as the appeal to nature. In short, it means “It’s natural so it’s good” with the converse being “unnatural is bad.” In general, the term “natural” has a positive perception, so calling a product (or a health intervention) “natural” is implying goodness. The appeal to nature is so common that you may not even recognize it as a logical fallacy. Unnatural can be good, and natural can be bad: Eyeglasses are unnatural. And cyanide is natural. Natural doesn’t mean safe or effective. But the appeal to nature is powerful, and it’s even persuasive to governments. If we believe that health interventions and treatments should be evaluated on their merits, rather than whether or not they’re “natural”, then decisions to regulate “natural” products differently than the “unnatural” ones (like drugs) makes little sense. Yet the Dietary Supplement Health and Education Act was a legislative appeal to nature, introducing a different regulatory and safety standard for a group of products while drawing a fallacious distinction with “unnatural” products like drugs. Canada fell for the appeal to nature too: It has the Natural Health Products Regulations which entrenched a lowered bar for efficacy and safety for anything a manufacturer can demonstrate is somehow “natural”. (more…)

Posted in: Science and Medicine, Science and the Media

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Does treating fever spread influenza?

Influenza

One of these things is not like the other

Treating a fever with medication like Advil or Tylenol is reflex action when we come down with colds and influenza. But could treating fevers actually worsen an illness and contribute to its spread in the population? That’s the impression you may have gained from the headlines and press last week, where antipyretics (fever-reducing medications) were described as some type of “anti-vaccine”:

Fever-reducing meds encourage spread of flu: McMaster report

Taking over-the-counter flu medication to cut your fever might help you feel better, but it might not be so good for the people you come into contact with.

When it comes to fever, your mother really did know what’s best

Who would have thought that the simple giving of a fever reducing agent, to either one of our family members or ourselves before we go off to school or work, may inadvertently lead to the death of someone that we see that day?

Use of fever-reducing drugs may lead to tens of thousands more influenza cases

The bottom line is that fever suppression increases the number of annual cases by approximately five per cent, corresponding to more than 1,000 additional deaths from influenza in a typical year across North America.

(more…)

Posted in: Epidemiology, Pharmaceuticals, Science and Medicine

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Even in 2014, influenza kills

I don’t think it can be repeated too many times during flu season: People can die of the flu.

The flu vaccine is one of the two vaccines most easily demonized by the antivaccine movement. The first, of course, is Gardasil (or Cervarix), the vaccine against HPV. The reason why Gardasil is so easily demonized is because it protects against an infection whose end result of cancer is many years in the future. Alt-med fans frequently castigate “conventional medicine” for not emphasizing prevention enough, but HPV vaccines put the lie to that. HPV vaccines protect against an infection that is usually fairly harmless in and of itself but has the long term effect of vastly increasing the risk of at least one potentially deadly cancer, and likely several others. Also, HPV infections are commonly sexually transmitted, allowing the moralistic wing of the antivaccine movement and misguided religious people in essence to “slut shame” the vaccine by arguing that it will encourage promiscuity by removing one of the consequences of sexual intercourse, one of the stupidest arguments against the HPV in existence. (Seriously, does anyone think teens and young adults, when their hormones are raging, worry about maybe the possibility of maybe getting cancer 20 years down the road when on the verge of a night of passion now? I don’t.) (more…)

Posted in: Public Health, Vaccines

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Beyond the flu shot: A closer look at the “alternatives”

Once again, it’s influenza season. The vaccine clinics are open, and the hysterical posts about the vaccine’s danger are appearing in social media. There’s familiarity to all of this, but also a big new change – at least in Canada, where I am. Pharmacists can now administer the vaccine. And it’s completely free to anyone in Ontario (where I am), so the barriers to obtaining the vaccine are pretty much eliminated. There’s no longer a need to drag your kids to their family doctor or line up at a public health clinic. Anyone can walk into a pharmacy, show their health card, and walk out minutes later, vaccinated.  It’s another enabling change that may help improve immunization rates, as uptake rates in the population remain modest.

This year’s flu season is (as of week 47) fairly quiet. Google Flu trends suggests a fairly typical picture, nothing like what we saw in 2009/10, the year of H1N1. My city’s influenza tracker reports only a dozen cases so far this season. Many of us will get our flu shot, continue with our lives, and not think about the flu until next season’s announcements. That’s the hope, anyway. Influenza can kill, and in its more virulent forms, is devastatingly deadly. The worst case scenario (so far) is almost unimaginable today. In 1918/19 an influenza pandemic killed 50 million people worldwide (5% of the population). So among public health professionals, that worry about the next wave is always present. Much has been written at this blog <plug>nicely compiled in the SBM ebook,</plug> on the efficacy and safety of the flu vaccine. In short, the vaccine is effective for both individual and population-level protection, but only modestly so, and its effectiveness varies based on its match with circulating strains. And despite widespread use for decades, there are frustrating limitations with the current vaccine beyond efficacy, including the need to repeat the shot annually. Someone said something about “going to battle with the army you have”. (I thought it was Crislip but he was quoting Rumsfeld.) The quote is apt. It’s not a perfect vaccine, but it does offer protection – if not directly to you, then indirectly to those at greater risk of infection. Hospitals and health facilities have been criticized for demanding health professionals either get the vaccine or wear a mask – and the arguments against vaccination are losing. But even the strongest advocates of influenza vaccine will acknowledge its limitations, which perhaps contributes to the understandable perception that there is more that could be done- beyond reasonable and effective precautions like handwashing and hygiene. (more…)

Posted in: Herbs & Supplements, Homeopathy, Vaccines

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Testing a Chinese Herbal Flu Remedy

During the early days of the 2009 H1N1 influenza A pandemic, the popular herbal formula maxingshigan–yinqiaosan was used widely by TCM practitioners to reduce symptoms. (It’s hard to pronounce and spell, so I’ll refer to it as M-Y.) A new study was done to test whether M-Y worked and to compare it to the prescription drug oseltamivir. It showed that M-Y did not work for the purpose it was being used for: it did not reduce symptoms, although it did reduce the duration of one sign, fever, allowing researchers to claim they had proved that it works as well as oseltamivir.

“Oseltamivir Compared With the Chinese Traditional Therapy: Maxingshigan–Yinqiaosan in the Treatment of H1N1 Influenza” by Wang et al. was published in the Annals of Internal Medicine earlier this month. The study was done in China, which is notorious for only publishing positive studies. Even if it were an impeccable study, we would have to wonder if other studies with unfavorable results had been “file-drawered.” It’s not impeccable; it’s seriously peccable.

It was randomized, prospective, and controlled; but not placebo controlled, because they couldn’t figure out how to prepare an adequate placebo control. They considered that including a no treatment group compensated for not using a placebo control, and that objective temperature measurement could be expected to get around any bias. It might not: the nurses who took the temperatures were blinded to the study, but the patients were not. It’s possible that those who knew they were getting M-Y might have believed in it and their bias might have somehow subtly influenced data gathering so that M-Y appeared more equivalent to oseltamivir than it actually was.

There are other problems besides the lack of blinding. (more…)

Posted in: Herbs & Supplements

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Lest We Forget: Influenza Can Be Devastating

One of our readers suggested that I review the book The Great Influenza: The Epic Story of the Deadliest Plague in History, by John M. Barry. It’s not a new book (it was published in 2004) but it is very pertinent to several of the issues that we have been discussing on this blog, especially in regards to the current anti-vaccine movement. It’s well worth reading for its historical insights, for its illumination of the scientific method, and for its accurate reporting of what science has learned about influenza.

In the great flu epidemic of 1918, influenza killed as many people in 24 weeks as AIDS has killed in 24 years. It’s hard to even imagine what that must have been like, but this book helps us imagine it. It tells horror stories: children found alone and starving beside the corpses of their parents in homes where all the adults had died, decomposing bodies piling up because there was no one left who was healthy enough to bury them. Sometimes the disease developed with stunning rapidity: during one 3 mile streetcar trip, the conductor, 3 passengers, and the driver died. In another incident, apparently healthy soldiers were being transferred to a new post by train; during the trip, men started coughing, bleeding, and collapsing; and by the time it arrived at its destination, 25% of the soldiers were so sick they had to be taken directly from train to hospital. 2/3 of them were eventually hospitalized in all, and 10% of them died. The mind boggles. (more…)

Posted in: Book & movie reviews, History, Public Health

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High Dose Flu Vaccine for the Elderly

Dr. Novella  has recently written about this year’s seasonal flu vaccine and Dr. Crislip has reviewed the evidence for flu vaccine efficacy.

There’s one little wrinkle that they didn’t address — one that I’m more attuned to because I’m older than they are.  I got my Medicare card last summer, so I am now officially one of the elderly. A recent review by Goodwin et al. showed that the antibody response to flu vaccines is significantly lower in the elderly.  They called for a more immunogenic vaccine formulation for that age group. My age group.

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Posted in: Vaccines

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A temporary reprieve from legislative madness

While doctor visits for influenza-like illnesses seem to be trending downward again, and ”swine flu” is becoming old news, I’d like to draw attention to an H1N1 story that has received very little coverage by the mainstream media.

Doctors in several states can now protect their most vulnerable patients from the H1N1 virus without worrying about breaking the law. In order to save lives, several states have announced emergency waivers of their own inane public health laws, which ban the use of thimerosal-containing vaccines for pregnant women and young children.

Legislators in California, New York, Illinois, Missouri, Iowa, Delaware, and Washington state have enacted these science-ignoring laws in response to pressures from the anti-vaccine lobby and fear-struck constituents. Except for minor differences, each state’s law is essentially the same, so I will focus on the one from my state of New York.

New York State Public Health Law §2112 became effective on July 1, 2008. It prohibits the administration of vaccines containing more than trace amounts of thimerosal to woman who know they are pregnant, and to children under the age of 3. The term “trace amounts” is defined by this law as 0.625 micrograms of mercury per 0.25 mL dose of influenza vaccine for children under 3, or 0.5 micrograms per 0.5 mL dose of all other vaccines for children under 3 and pregnant women. Because thimerosal (and thus, mercury) exists only in multi-dose vials of the influenza vaccines (both seasonal and novel H1N1), this law really only applies to these vaccines. The mercury concentration of the influenza vaccines is 25 micrograms per 0.5 mL, which therefore makes their use illegal. Unfortunately, the only form of the H1N1 vaccine initially distributed, and that could be used for young children and pregnant women, was the thimerosal-containing form. The thimerosal-free vaccine was the last to ship, and in low supply, and the nasal spray is a live-virus vaccine, not approved for use in pregnancy or children under 2. That meant, without a waiver of the thimerosal ban, these groups could not be vaccinated.
(more…)

Posted in: Politics and Regulation, Public Health, Science and Medicine, Vaccines

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Even with the H1N1 pandemic flu strain going around, you should still be vaccinated against the seasonal flu

Even with the H1N1 pandemic flu going around you should still be vaccinated against the seasonal flu. revere has the details. Read. Enjoy. Be educated.

I guess that means Dr. Doug Bremner must think that revere is an idiot. After all, Bremner tells us that the flu vaccine is all a plot for big pharma to make money, don’t you know? Subtlety and weighing of risk-benefit ratios in a manner that doesn’t turn into an anti-big pharma rant is beyond him, as both Peter Lipson and I discussed (and Peter discussed again) not too long ago.

Fortunately it is not beyond revere to rationally weigh the risks and benefits of being vaccinated:

The truth is this. No one knows what’s going to happen. We’re all guessing. But in my estimation, the risk-benefit calculation for vaccine side-effects and flu is so markedly in favor of the vaccine that I made the decision to get vaccinated and that’s what I’d advise others, too. How confident am I? I’m confident it is the most rational thing to do given what we know.

Exactly. It is quite possible to look at the evidence and science and decide that the risk-benefit ratio is so much in favor of vaccination that it makes sense to be vaccinated. It’s also possible to look at the same literature and be less enthusiastic. You don’t need to appeal to big pharma conspiracy theories, and, in fact, such appeals only muddy the issue unnecessarily.

I’d love to see Bremner try to counter the arguments of a highly respected senior epidemiologist who can calmly discuss the pros and cons of flu vaccines from a scientific and practical standpoint based on evidence. Bremner points to “experts” who say that vaccination against the seasonal flu is a waste of money and time, but here’s one expert I bet that Bremner can’t refute. I won’t hold my breath waiting for him to try, though. It’s so much easier just to say that you’re an idiot if you get vaccinated against the seasonal flu. Obviously, in Bremner’s world, revere must be in the thrall of big pharma and pro-vaccination ideology.

Just like me, I guess.

Posted in: Public Health, Vaccines

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