Thursday, October 22, 2015

How Good is a Flu Shot? Likely 1-3% chance it will prevent you from getting influenza this year/Lown Institute Blog

Written by Alan Cassels, a British Columbia drug policy researcher, via Lown Institute Weekly:
“Normally, the flu vaccine is between 50 to 60 percent effective”— Dr. Tom Frieden, Director of the Centers for Disease Control and Prevention (CDC)
How effective is the flu shot?   
That’s an important question that generates many headlines across North America every fall as the public health community starts ramping up its fall flu campaigns. Problem is, the media tends to generate a lot of noise around that number, but provide very little clarity.
Influenza stories this time of year swirl around similar themes, often with the CDC taking center stage (featuring the platitudinous photo op of the CDC director rolling up his sleeve for the shot), including the importance of the flu shot, the need for general hand hygiene and the expected effectiveness of the vaccine this year.
The number that arrives as predictably as the fall flu campaign is “60” as in this storythat repeats the mantra: “Flu shots normally prevent 60% to 65% of infections serious enough for people to see a doctor.” Across North America, public health officers will stress that the flu vaccine “reduces the risk by 60%!” Sixty sounds good. Impressive. Powerful. But ultimately as meaningless as a used car salesman with big bright signs of “60% off” plastered on every car on the lot, without ever telling you what the regular prices are. Despite the potential for a huge bargain on that purchase, the reality is that you’re in for a much smaller deal than you think you are. MUCH smaller.
And so it goes with the flu shot. When people hear “60% reduction,” I believe this is what happens inside their thought bubble: “If my risk of getting the flu this winter is 100%, the shot will reduce that to 40%. So instead of 100 people getting the flu, only 40 would get it. Hmmm. This 60% reduction sounds like great odds.”   
Even when the flu vaccine seems less effective, like in this story which said that “last year the flu shot, by the CDC’s own numbers, was 23% effective,” people might think it’s a good deal. 23% off that Chevy Impala in the back lot might be a great bargain. But what does the 23% or 60% really mean?  
Since they are relative numbers, they demand us to ask “23% of what?” or “60% of what?”  As we’ve made abundantly clear at, using relative numbers on their own are a statistical no-no because, to quote ourselves, “we think the relative risk number tends to inflate the impression of how much impact the drug [or vaccine] has.” For a quick refresher on relative numbers check out our review criteria here.
I find the 60 or the 23 percents irritating, not to mention epically misleading and I’m not alone. One commentator looking at a flu study reporting a “24% risk reduction” called it “Cockamamie propaganda”. Colorful but true.  
To get some perspective I talked to Dr. Tom Jefferson in Rome who has reviewed hundreds of flu vaccine studies as part of the Cochrane Collaboration. Dr. Jefferson gives me a quick tutorial on the 60% which he calls “CDC / pharma spin of the worst kind.”
He reminded me that every flu season there are over 200 viruses which can cause influenza and influenza-like illness, all perfectly capable of making you headachy and feverish. Most people get through the flu just fine and, thankfully, the risk of death or serious illness in otherwise healthy people is rare. In a good year the vaccine might protect you against influenza A and B, which might make up about one tenth of all circulating viruses.
The best way to assess flu trials is to look at those that compared vaccinated people with unvaccinated people.  
When Jefferson and his colleagues published their March 2014 review they found that under ideal conditions (when the vaccine matches the main viruses circulating that season) you need to vaccinate 33 healthy adults to avoid one set of influenza symptoms. This is what we’d call a NNV (Numbers needed to Vaccinate) of 33. When the vaccine match isn’t so good as it was last year, the NNV is about 100. That is, of 100 people vaccinated, 99 will have no benefit and one person will avoid one set of influenza symptoms. Vaccination did not seem to affect the number of people hospitalised or who lost working days.     
Almost half (15 of the 36 trials they examined) were funded by vaccine companies and four had no funding declaration. His team cautioned that even these numbers may represent an “optimistic estimate” because “company-sponsored influenza vaccines trials tend to produce results favorable to their products.” You can read more details here.
As for the magical “60?” Dr. Tom Jefferson didn’t mince words: “Sorry I have no idea where the 60% comes from – it’s either pure propaganda or bandied about by people who do not understand epidemiology. In both cases they should not be making policy as they do not know what they are talking about,” he said, insisting that I quote him.
When asked to explain the 60% number via email, the CDC sent me a link to their website, which states that the 60% figure is a “point estimate” of laboratory-confirmed flu illness that results in a doctor’s visit or urgent care visit, presumably derived from studies such as this one showing a “61%” effectiveness rate for the 2013/2014 shot.
If you don’t go beyond the “60%” headlines, you probably wouldn’t question the vaccine because if A) the vaccine is so effective, B) the vaccine is ‘free’ or almost free; and C) it’s relatively safe, then how could you say no to that?
Doesn’t that equation change if the effectiveness is between 1 to 3 percent, depending on how well this season’s circulating virus has been matched with the new vaccines? 
As the CDC continues to stress that “a yearly flu vaccination is still the best protection currently available against the flu,” you can imagine the confusion playing out in the thought bubbles of the general population.  
What I long for—and I haven’t seen it yet—is for media coverage this season to start reporting on absolute differences related to the flu vaccine. I’d like to see how the “1-3% effectiveness of the vaccine” floats around in the public’s thought bubbles. How does that compare with something as simple as staying home and not infecting other people or washing your hands more frequently?
I think if the real numbers were out there, we might see a much broader public conversation about what other sorts of flu “protection” are worthwhile.

Saturday, October 3, 2015

WaPo Claims it is Too Dangerous for Presidential Candidates to Discuss the Vaccine Sacred Cow

Several Republican Presidential candidates (Donald Trump, Dr. Ben Carson and Dr. Rand Paul) were asked in the debate September 16 about their opinion of whether vaccines are linked to autism.  Trump said yes, vaccines cause autism.  He gave examples of his employees whose normal children regressed into autism shortly after a vaccination.

Dr. Ben Carson, a retired pediatric neurosurgeon, hedged.  Vaccines are good, but not always for everybody. Quoted in the WaPo, Carson said:
“Vaccines are very important,” Carson said, before qualifying: “Certain ones. The ones that would prevent death or crippling. There are others, there are a multitude of vaccines which probably don’t fit in that category, and there should be some discretion in those cases.”
Dr. Rand Paul, an ophthalmologist, is all for vaccines, "But I'm also for freedom." Both he and Trump think vaccines should be spread out.  Trump  wants "smaller doses over a longer period of time." Carson seemed to agree with this. "It is true that we are probably giving way too many in too short a period of time," he said. "And a lot of pediatricians now recognize that, and, I think, are cutting down on the number and the proximity in which those are done, and I think that's appropriate."

CBS has posted video and transcribed this part of the vaccine debate.

Stop the presses.  Three Presidential candidates (2 who are MDs) share the view that too many vaccines are given too close together.  Not every vaccine needs to be forced on every child.  Yet they like vaccines.  They feel they could be used more wisely.

I share this opinion, as do tens (or hundreds) of millions of Americans.

But the Washington Post published a hatchet piece criticizing the three candidates' answers. The WaPo piece was titled "GOP's dangerous 'debate' on vaccines and autism."  Wow.  A subject too dangerous to debate.  Really?  Why is this discussion dangerous?

Because WaPo, mainstream media and the nanny state are intent on controlling the vaccine debate.  They want the debate limited to two positions only:  CDC staff and hand-picked "experts" who favor one-size-fits-all vaccine mandates, on the one hand, and the ignorant "crazies" who are against all vaccines for everyone, on the other.

The media (and especially the WaPo) are doing their darnedest to pretend the reasonable middle ground in the vaccine debate does not exist. In this case, they are trying to silence three Presidential candidates, two of whom happen to be physicians and probably more knowledgeable than WaPo journalist Michael Miller.

The media have created a straw man: a self-indulgent, anti-science, anti-vaccine caricature that the media can disparage and destroy. It has to be all or nothing:  you favor forcing every child to receive every government-designated vaccine that is added to the schedule by CDC, or you hate vaccines, period. Reasonable facts and and opinions will not be allowed in this debate. Freedom to pick and choose your vaccines, when you deem they are desirable--which until recently was the norm--has become anathema.  Such ideas are too dangerous.  Better to deny them any hint of legitimacy and definitely no prime time. Reporter Sharyl Atkisson recently wrote about how the media ignore or demean substantial scientific evidence linking vaccines to neurologic injuries and autism.

But now three Presidential candidates have carved out similar turf:  talking about a more reasoned vaccine policy.  Presumably they don't think their opinions will be as problematic for the voters as they are for the Post.  Here's why.  Despite the CDC/media mantra that all vaccines are safe, the public has doubts.

A significant minority of Americans think that vaccines may have something to do with autism, or other neurologic impairments in children.  A 2011 Harris poll discussed in USNews found that only 52% of Americans were sure vaccines did not cause autism.  The rest of us are not so sure...

The American Academy of Pediatrics (AAP) inserted itself into the Republican debate, tweeting shortly after the broadcast:  "Vaccines are safe. Vaccines are effective. Vaccines save lives."  Well, AAP, you may represent the pediatricians of America, but it is high time you learned that vaccines are drugs--according to FDA--and all drugs are safe to a degree, effective to a degree, and kill some people, sometimes.  If all were safe all the time, why would we need doctors to prescribe them?  AAP, be careful you don't tweet yourself out of a job.

UPDATE:  I forgot that in order to increase vaccinations, pharmacists may now prescribe and immediately administer vaccines (via so-called "protocols"), even to children.  In 39 states, pharmacy interns can administer vaccines.

The local pharmacist at a national chain told me she has a vaccination quota to meet. Doctors and hospitals have vaccine quotas too, when insurers like Medicare designate vaccination rates a "quality measure."

Was a vaccine recommended to you in order to meet the corporate/government quota?

US Airstrike bombs MSF hospital in Kunduz, Afghanistan relentlessly for an hour, despite knowing its location/ Reuters, NYT, Guardian

UPDATE:  From the Oct 11 WaPo:
The AC-130U plane, circling above in the dark, raked the medical compound with bursts of cannon fire, potentially even using high explosive incendiary munitions, for more than an hour. The assault left at least 22 people dead, some of them burned to death.
A US airstrike on Kuduz repeatedly strafed the MSF (Medicins Sans Frontieres or Doctors Without Borders) hospital in Kunduz, the only tertiary care hospital in the area--which treats the wounded from all sides--even after calls to US military HQ by MSF begging it to stop.  At least 19 medical staff and patients died, some from burns in the ensuing fires. The UN High Commissioner for Refugees said this may qualify as a war crime.

From the NY Times:
In a statement, the aid group accused the American military of continuing the bombing for 30 minutes after receiving phone calls telling military contacts that the hospital was being bombed.
“All parties to the conflict including in Kabul and Washington, were clearly informed of the precise location [GPS Coordinates] of the MSF facilities — hospital, guesthouse, office,” the statement said. “MSF urgently seeks clarity on exactly what took place and how this terrible event could have happened,” it said.
From Reuters:
Almost 200 patients and employees were in the hospital, the only one in the region that can deal with major injuries, said Medecins Sans Frontieres, which raised the death toll to at least 16 by late on Saturday.
"We are deeply shocked by the attack, the killing of our staff and patients and the heavy toll it has inflicted on healthcare in Kunduz," operations director Bart Janssens said in a statement.
MSF said it gave the location of the hospital to both Afghan and U.S. forces several times in the past few months, most recently this week, to avoid being caught in crossfire.
From The Guardian:
“Why did the US blow up the whole hospital?” said Nasratullah, whose 25-year old cousin Akbar was among the doctors killed. “We know that the Americans are very clever. If they can target a single person in a car from their planes, why did they have to blow up the whole building?”
The charity said it had recently recirculated GPS coordinates of the hospital to all parties fighting in the conflict, even though it has been operating for years and is one of few medical facilities in the city so should have been well known.
Human Rights Watch said it had serious concerns about whether US forces had taken sufficient precautions to avoid striking such a sensitive target. Hospitals are among areas protected from attack under international laws governing conflict.