Showing posts with label vaccines. Show all posts
Showing posts with label vaccines. Show all posts

Tuesday, February 10, 2015

What Would Jesus Do About Measles?


What happens when faith reaches its zenith? Children get hurt and die. In the case of under-vaccination, it's not just the children of the most faithful who suffer; the rest of us do, too.

Today, I present to you Dr. Paul Offit's timely NYT Op-Ed on religious exemptions to vaccination. Join the call to remove religious exemptions for vaccination. If god exists, surely they disappoint him, too.


PHILADELPHIA — MEASLES is back. Last year, about 650 cases were reported in the United States — the largest outbreak in almost 20 years. This year, more than a hundred have already been reported.

Parents have chosen not to vaccinate their children because they can; 19 states have philosophical exemptions to vaccination, and 47 have religious exemptions. The other reason is that parents are not scared of the disease. But I’m scared. I lived through the 1991 Philadelphia measles epidemic.

Between October 1990 and June 1991, more than 1,400 people living in Philadelphia were infected with measles, and nine children died. The epidemic started when, after returning from a trip to Spain, a teenager with a blotchy rash attended a rock concert at the Spectrum. By Nov. 29, 96 schoolchildren had been stricken with the illness; a week later, it was 124; by the end of December, the number had risen to 258, and the first child had died. The Centers for Disease Control and Prevention sent a team to determine whether the strain of measles was particularly virulent. It wasn’t. Investigators found that the deaths had nothing to do with the strain that was circulating and everything to do with the parents.

Two fundamentalist Christian churches — Faith Tabernacle Congregation and First Century Gospel Church — were at the heart of the outbreak. Children had not been vaccinated, and when they became ill, their parents prayed instead of taking them to the hospital to receive the intravenous fluids or oxygen that could have saved their lives of those with the worst cases. “If I go to God and ask him to heal my body,” said a church member, Gordon Korn, “I can’t go to a doctor for medicine. You either trust God or you trust man.”

Public health officials turned to the courts to intervene. First, they got a court order to examine the churches’ children in their homes, then to admit children to the hospital for medical care. Finally, they did something that had never been done before or since: They got a court order to vaccinate children against their parents’ will. Children were briefly made wards of the state, vaccinated and returned to their parents. At the time, a religious exemption to vaccination had been on the books in Pennsylvania for about a decade.

To prevent doctors from violating his church’s beliefs against vaccination, the pastor of the Faith Tabernacle Church asked the American Civil Liberties Union to represent him. It refused. “There is certainly a free exercise of religion claim by the parents,” said Deborah Levy, of the Philadelphia chapter of the A.C.L.U., “but there is also a competing claim that parents don’t have the right to martyr their children.”

When spring came and the epidemic faded, C.D.C. officials published the results of their investigation. Over a third of those infected — 486 of 1,424 — belonged to one of those two churches, as did six of the nine dead children.

At the Children’s Hospital of Philadelphia, we saw more than 200 children in our emergency department and admitted about 40. Children would come in, covered in rashes, squinting in the bright light (a side effect caused by eye irritation), struggling to breathe and often extremely dehydrated. It was like being in a war zone. When I asked their parents why they had done what they had done, they all had the same answer: “Jesus was my doctor.”

It seems to me that if religion teaches us anything, it’s to care about our children, to keep them safe. Independent of whether one believes in Jesus, or that the four Gospels are an accurate account of what he said and did, you have to be impressed by the figure described. At the time of Jesus, around 4 B.C. to 30 A.D., child abuse was the “crying vice” of the Roman Empire. Infanticide and abandonment were common. Children were property, no different from slaves. But Jesus stood up for children. In Matthew 25:40, he said, “Verily, I say unto you, Inasmuch as ye have done it unto one of the least of my brethren ye have done it unto me” — a quote that could be emblazoned onto the entranceway of every children’s hospital in the world.

Constantine, the first Christian emperor of Rome, passed laws protecting children from abuse and poverty. Christian monasteries became prototypes for modern-day hospitals. And missionaries brought medicine to the four corners of the earth in Jesus’ name.

So why didn’t representatives from other churches or other religions stand up for the children suffering from measles in Philadelphia? The reason is obvious. No one likes to tell someone else how to practice their faith. It’s an understandable instinct — to a point. And that point was reached in Philadelphia in 1991.

In the wake of the current epidemic, several states have proposed legislation modifying or eliminating philosophical exemptions to vaccination. No lawmaker, however, dares to touch religious exemptions. It’s political dynamite. But with an estimated 30,000 children in the United States unvaccinated for religious reasons, that is a dangerous mistake.

Parents shouldn’t be allowed to martyr their children — or in this case, those with whom their children have come in contact. Religious exemptions to vaccination are a contradiction in terms. In the good name of all religions, they should be eliminated.

Sunday, February 8, 2015

The question anti-vaxxers should have to answer


With measles eliminated from America a few years ago (consider what an awe-inspiring achievement that is), anti-vaccination madness is once again an issue as outbreaks are now occurring all over the continent, sadly, including the happiest place on Earth. The outbreaks are traceable to pockets of under vaccination leading many to ask the same question: what can be done to change the anti-vaxxers' minds?

This is a very important question in light of a recent study undertaken by Brendan Nyhan and colleagues. They randomly contacted Americans by phone to participate in an on-line examination of the effects of 4 different kinds of messages on subjects' (1) self reported attitudes towards MMR vaccine and (2) their propensity to use the vaccine in the future.  Although a message correcting misinformation about the MMR vaccine causing autism changed respondents' minds about that particular concern, none of the interventions increased the respondents propensity to use the vaccine in the future; they actually decreased it.

How depressing.

What will change the minds of anti-vaxxers?

I suggest that we ask them that question.

Anti-vaxxers should be asked to consider the following scenario: imagine that we live in a world where the MMR vaccine is 99% effective at preventing MMR infection with only a 1 in a million risk of a serious adverse event, like a life-threatening allergic reaction. That's it - no risk of the vaccine causing any other adverse effects. Period. And we know this for a fact. Close your eyes, take a deep breath, and as you exhale, let the imaginary scenario where that is perfectly true sink deeply in.

Anti-vaxxers should have to tell the rest of us what it would take to convince them that that is indeed true. Remember, for the sake of argument, it is true. The question is what would be required for them to recognize and acknowledge that it is.

Here's the catch: children would still be developing features and diagnoses of autism, MS, hepatitis, arthritis, learning and behavioral disabilities, and a host of other mysterious disorders some time after getting vaccinated, even though none of those conditions would, in our imaginary scenario, be causally related to the MMR vaccine. What would it take to convince them that that was the case despite those coincident occurrences happening to kids and families everywhere?

That is the crux, isn't it? The truth is that we simply cannot trust our personal experiences (and those of our friends and family as well) to draw any conclusions about events like these. They are completely unreliable. Only population based studies and large randomized trials can reliably inform us about potential causal correlations like these. Asking anti-vaxxers this question forces them to struggle with that fact. In the end, I think that there are only 2 possible kinds of responses.

First, some would realize that nothing could convince them of the truth of such a scenario. These people may never change their minds - they aren't open to having their minds changed. Unfortunately, this stance indicates a complete unwillingness to even try to recognize a real world scenario that might actually be true and that would actually be wonderful. All too common, stances such as these - the definition of irrationality - are dangerous conversation stoppers. Perhaps peer-pressure, mockery, satire, and ridicule would work, but no amount of evidence would seem likely to satisfy.

The second response would have to be some kind of evidence. What else?

And so it would seem that if there are anti-vaxxers that are open to having their minds changed (and there are), despite Nyhan's study results, the thing that will do the trick must be evidence. That's a very good thing, because as long as the conversation is one about evidence, there is a conversation to be had. The key will be determining what kind of evidence may be required and how to best present it so as to have have the greatest impact. Nyhan's important work remind us that we should study the effects of our efforts to change minds very carefully. I suggest that anti-vaxxers themselves should be the ones telling us where to start.

You know that imaginary scenario I described above? It's actually pretty close to the truth.

Wednesday, March 12, 2014

What doctors and anti-vaxxers have in common: Part 2



When I openly pose the post-vaccine fever scenario, most people consider it more likely than not that the vaccine caused the fever. That is, most people think the chance that the vaccine caused the fever is > 50%. Almost every medical student in a group of 20 that I was teaching a few weeks ago thought that. After all, fever is a well-recognized side effect of vaccine injections and your child was perfectly fine until a few days after the injection. Who wouldn’t reasonably conclude that the vaccine likely caused the fever?

Notice that by focusing responses on 1-49%, I set the question up to give you a better chance at being correct than they were but still, nobody got the question right. Don't worry. You are in good company. For now, just remember the feeling you had when you made your choice.

Back in the 80’s, investigators were concerned that combining mumps, measles, and rubella vaccines into one (MMR) might increase the risk of side effects, so some doctors in Finland did an ingenious study to determine what was not just temporally associated with vaccine injection, but caused by vaccine injection.

They studied 581 pairs of twins and randomly gave the MMR injection to one of the twins and a placebo injection to the other. Then, so as to not deprive the children that got a placebo injection of the vaccine's proven benefits, three weeks later, they gave each twin the opposite of what they had earlier received. Parents, who were blinded (they didn’t know when the kids were getting the placebo or the MMR injection), were instructed to vigilantly check for fever and a variety of other potential side effects after each injection.

In the first 6 days after placebo injection, 17% of children had a fever. That’s the background frequency of fever in vaccine-age children, and it's pretty high, huh? On the other hand, in the first 6 days after MMR injection, 17.2% of children got a fever. The difference - 0.2% - is what can be causally attributed to the active ingredients in the vaccine.

Conclusion: >99% of fevers that occur in the first week after MMR injection have nothing to do with the vaccine at all

However, we are very likely to erroneously attribute the fever to the vaccine. We do this because we have a powerful intuition that leads us to identify a causal relationship when 2 events that could possibly be causally related follow each other in time. We are mistaking what is merely possible for what is probable. Unfortunately, children develop mysterious illnesses like MS, autism, epilepsy, hepatitis, arthritis, etc. with regular frequency. Sometimes, those illnesses will appear fairly soon after getting a vaccination, and that’s when that intuition of ours can do some serious damage. That same intuition does damage when mysterious conditions like these disappear -as they often spontaneously do- after interventions that have no effect on the disease like prayer, acupuncture, chiropractic neck manipulations, homeopathic remedies, etc. Only randomized controlled trials can sort this stuff out.

Imagine once again your son who got a fever early after the MMR injection, only now, he is a healthy 18-year-old man who was spared the ravages of mumps, measles, and rubella. At any point in his upbringing, would you have ever had cause to stop and be thankful for the vaccine? How could you? You’d have had no way of knowing whether your child would have contracted one of these illness had he not been vaccinated!

See what’s happening here? The way that we experience life offers us no way to identify the situation where a vaccine prevents a horrible illness or death. On the other hand, we have a tendency to erroneously attribute adverse events to vaccines when they follow each other in time. Remember how you felt about your child's fever after MMR vaccine? Parents considering whether to vaccinate their children can anticipate the regret that they will experience if their child does develop an illness like autism afterwards, but they cannot anticipate the relief that they cannot experience when their child is spared a vaccine-preventable illness. Anti-vaxxers are much more likely to anticipate the former type of regret than the latter because they tend to overestimate the risks of vaccines and underestimate their benefits. Our intuitions erroneously set vaccines up to be unattractive. 

And so it is with physicians and oral anticoagulants (OAC’s). Bleeding events are fairly common. Whenever somebody experiences a bleeding event on an OAC, they and the doctors tasked with treating the bleeding blame the OAC. The reality is that most bleeding events that happen while on an OAC would have happened otherwise: just as only 0.2% of fevers early after the MMR injection were caused by it, only 0.2-0.3% of bleeds /yr are caused by the OAC. But physicians can anticipate the regret that they will experience when they prescribe an OAC to a person with atrial fibrillation (AF) who then develops a bleeding event. The finger of blame will point to the OAC and the physician who prescribed it. Unfortunately, nobody ever returns to the prescribing physician to pat them on the back and thank them for the stroke that they and the OAC prevented because, just like the case of mumps that your son avoided, there is no way to recognize a stroke that would otherwise have happened. Doctors' intuitions erroneously set OACs up to be unattractive.


Our ancestors evolved on an African Savannah with no pressures to select for intuitions that address the types of complicated primary prevention questions posed by vaccination and OAC use in AF. It seems that we did evolve intuitions that lead us to readily identify patterns and infer causal relations where there often isn't one. On the whole, this rudimentary heuristic has done well to protect us from certain kinds of dangers, but, as Sam Harris has written, “we have flown the perch built for us by evolution”. If we are to make advances with complex questions, we simply have to recognize when our intuitions lead us astray, and they regularly do, whether we are specialized physicians or lay people. None of us are spared the consequences of irrationality. It is a struggle we all must recognize and participate in.

If you are faced with complex decisions like vaccinating or taking an OAC, I hope that you are most heavily weighing the evidence from RCTs. If you aren't, then I hope that you are seeking the involvement of people who are. Otherwise, you're just being irrational.

Saturday, March 8, 2014

What doctors and anti-vaxxers have in common: Part 1



A few years ago, a Canadian neurologist reviewed the case of every patient admitted to 12 Ontario hospitals  with a stroke between 2003 and 2007. He only studied patients with a heart rhythm disorder called atrial fibrillation (AF) because AF is known to cause blood clots inside the heart that can get pumped out and block a brain artery causing strokes. There is an abundance of clear evidence: people who suffer from AF can dramatically reduce their risk of stroke by taking oral anticoagulants (OACs) that prevent intracardiac clots from forming. These medications are to be avoided in people with bleeding problems, but otherwise, the majority of people with AF ought to take one.

Gladstone discovered something shocking: after excluding patients with bleeding risks, only 40% of people with AF who suffered a stroke were on an OAC when all of them ought to have been, and three quarters of them were under-treated. The data was even more staggering for patients with AF who were admitted with their second stroke – a situation where it ought to be blatantly obvious that an OAC is needed: only 57% of people were being treated and two thirds of them were undertreated. Overall, only about 15% of patients with AF were appropriately treated with an OAC. The conclusion was sobering: if these patients had been appropriately treated, the majority of these strokes could have been prevented.

Of course, part of the responsibility for not being on OACs rests with patients who decide not to take one, but this is one study among many that indicate that physicians around the world routinely under-prescribe OACs to people with AF. Is it because AF is rare and doctors just don’t know about the opportunity to prevent strokes by prescribing OACs? Consider that AF is the most common arrhythmia in adults and that you and everybody you know and love has a 1 in 4 chance of developing it at some point in life. Plus, it’s responsible for 20% of all strokes. Is it because the risks and benefits are unclear? Absolutely not: as I mentioned earlier, over 10 randomized trials done around the world by different investigators involving thousands of patients have all shown the same consistent results: at the cost of a small (0.3%/yr)increase in the risk of bleeding, OACs reduce the risk of stroke by around 65%.

So why are doctors not doing the obvious and prescribing these drugs?

What's the anti-OAC body count at today?

In my next blog entry, I’ll explain the situation, but first, I want you to consider the following common scenario: 

You have a young child who has been perfectly well until he receives a combined vaccine injection for mumps, measles, and rubella (MMR). Around 3-6 days after the shot, your son develops some irritability and he feels hot; his temperature is 38.9 degrees C. You give him some acetaminophen and in an hour, he defervesces and perks up. How likely do you think it is that the vaccine injection caused his fever?

(A) > 50%
(B) 31-50%
(C) 21-30%
(D) 11-20%
(E) 1-10%
(F) < 1%?

Don't Google it. Close your eyes and visualize the situation and try to be as honest as you can. You and your spouse are probably going to bring this very question up when the fever develops. What are you going to say? Tell us by anonymously voting in the poll on the right. (Poll now down.)

(Go to Part 2, and the answer)