FDA Study Explains The Trouble With Pertussis Vaccine (Loop Op-Ed)

Caveat:  This article is slightly different from the one published in The Loop on January 30th - it has been revised to apply to our entire region, rather than specifically Vashon Island.  Enjoy & Share!

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Good people are people who do their best. There are a lot of good people in our region, and we are a diverse group. That’s why “respect for diversity” matters. Sometimes another person’s choice will boggle our mind. When it does, hopefully we’ll realize we are boggling someone else’s mind, too! And aim for tolerance. A not-so-easy goal.  

Sadly, over the past few years, our respect for medical diversity has faltered. What you do in the doctor’s office has become public fodder for evaluation, debate, and ultimately, judgement.   

This message mostly centers around pertussis (whooping cough) and the commonly held belief that by vaccinating, you can protect yourself AND those around you. This is known as Herd Immunity. Or, if you don’t want to feel like a cow, Community Immunity.

It’s a great idea, and for some disease/vaccine combos it works. But, according to a new, highly-credible FDA/NIH study, attaining herd immunity for Whooping Cough with the current acellular pertussis vaccine is almost certainly a pipe dream.

Vaccines in America are produced by private companies, government is tasked with approval and oversight, and public health departments are expected to inform the public. The trouble is, vaccine science is complicated, sound bites under-inform, and fear is a powerful force.

The most popular pertussis vaccine myths in our region are: (1) if you vaccinate, then you won’t catch pertussis or transmit it to others, and (2) if more people vaccinated, we could achieve herd immunity!”     

So, this is the question of the hour: “Why is there a resurgence of pertussis in the U.S. when American vaccination rates are higher than ever?” Answer: “Because the vaccine doesn’t do what we thought it did.”

This new and highly regarded study shows that baboons vaccinated with aP (acellular pertussis vaccine) were protected from severe pertussis-associated symptoms but not from colonization, they did not clear the infection faster than non-vaccinated individuals, and they readily transmitted B. pertussis to unvaccinated contacts.  Individuals vaccinated with wP (the older whole cell pertussis vaccine) cleared the infection faster but still transmitted to contacts.  Meanwhile, previously infected baboons were not colonized nor capable of transmitting pertussis to contacts.  

According to Tod J. Merkel, lead author of the study, “When you’re newly vaccinated you are an asymptomatic carrier, which is good for you, but not for the population.” Fellow scientist, Jason Warfel went on to state: "Although pertussis resurgence is not completely understood, we hypothesize that current acellular pertussis vaccines fail to prevent colonization and transmission."   

Surprised? You shouldn’t be. As Emily Willingham states, in Forbes magazine, “Although this work was in baboons and baboons aren’t people, it provides compelling evidence for what many experts suspected: Acellular pertussis vaccine just isn’t very good at preventing pertussis transmission.”  http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm376937.htm

So, what’s the media to do? The past few years have been filled with stories such as The Stranger’s article by Goldy titled:  Stupid Fucking Anti-Vaccine Hippies, and the Seattle PI’s article, “What It’s Like To Have Whooping Cough At 31,” which quotes Julia Ioffe’s blog post, “I’ve Got Whooping Cough. Thanks a Lot, Jenny McCarthy.”  Lead editor of The New Republic, Julia ends her story with, “So thanks a lot, anti-vaccine parents. You took an ethical stand against big pharma....killed some babies and gave me...the whooping cough in the year 2013. I understand your wanting to raise your own children as you see fit, science be damned, but you're selfishly jeopardizing more than your own children. Carry your baby around in a sling, feed her organic banana mash while you drink your ethical coffee, fine, but what gives you denialists the right to put my health at risk...?”  

Thankfully, Julia Ioffe can now rest easy knowing that she probably caught pertussis from a cute, vaccinated, schoolgirl whose Mommy was completely unaware that her daughter was a walking, talking, bright-eyed little pertussis carrier. Or, her elderly neighbor who had an awful cough that just wouldn’t go away. Or her co-worker who coughed so hard she cracked a rib just before catching a flight to Atlanta for a business meeting. Or, her other co-worker who feels perfectly fine, just got the TdaP, and is visiting his newborn niece after work today? None of whom ever considered that they could have pertussis...because they were vaccinated.        

Does this mean you shouldn’t vaccinate for pertussis?  Of course not!  Tetanus only offers benefits to the recipient, so why not use the pertussis vaccine? If you wish to manage your health with vaccines. Of course, not everyone does. Some prefer to allow their children to experience pertussis naturally, watching for symptoms, working with their doctor, and staying home until they are no longer contagious. Remember, if both the vaccinated and the unvaccinated can be colonized by the bacterium and transmit it to others, then the obvious symptoms of the unvaccinated will at least raise a red flag. But, what if you or your child has a suppressed immune system, or asthma, or you’re just plain scared of the disease? By all means, take advantage of the personal protection the acellular vaccine offers you. Just don’t think you’re getting more than you’re getting.  

For now, no one knows 100% what’s happening and there is no viable vaccine option for creating herd immunity to pertussis. Until we know more, parents of newborns (and other vulnerable individuals) should continue to be cautious! This means, if you thought a person’s vaccination status automatically made them safe...think again.   

On the public front, let’s hope our doctors, public health nurses, public & private school administrators, media and activists will revamp their message to acknowledge the results of this game-changing study.   

~March Twisdale (an advocate for medical choice and informed consent who also is a parent with partially vaccinated children)

A Community Conversation - Part 10

A Community Conversation About Health and Responsibility: Vaccines and Beyond

Part 10:  Convoluted Policy-Making & Autism

Pure science is a beautiful and complex dance of careful planning and unexpected discoveries. But things get truly convoluted when we throw in money, public agendas, politics, media, and liability law.  Here’s how.

Before 1900, there were no federal regulations of pharmaceuticals and anyone could manufacture vaccines. Then tragedy struck. In what the newspapers later called “criminal carelessness,” contaminated vaccine batches killed at least 23 children. This led to the Biologics Control Act of 1902.  In addition to setting manufacturing standards for many types of medications, the Biologics Control Act put government in charge of safety enforcement and private industry in charge of manufacturing.

Why can you confidently buy a bottle of ibuprofen, and why are tainted batches found and recalled?  Because of a vaccine tragedy more than a hundred years ago, and how society responded to the problem.

Another incident, in 1955 drew considerable attention when Cutter Laboratories accidentally released an injectable polio vaccine in which the polio virus was not completely killed. There was no negligence involved and all procedures were followed properly. The polio virus was simply tougher than the scientific knowledge of the time understood. 40,000 children got polio, 200 were paralyzed, and 10 died. In response, the California Supreme Court ruled that Cutter Laboratories was not guilty of negligence, but was still liable for the harm done.

This precedent of “strict liability” would be devastating to the vaccine market. Freed of the necessity of proving negligence, the number of vaccine-related lawsuits skyrocketed. An additional problem was that doctors continued to assure patients that vaccines were absolutely safe, opening the door to lawsuits for “breach of warrantee.”

The truth is that vaccines, like all medical treatments, have risks. There is nothing that can be done to make vaccines absolutely safe. This fact is understood by the scientific and medical communities.  There is no debate.  And, caring for a single child with severe vaccine injuries can cost millions of dollars.  There are 74 million children in the USA.  Even if severe adverse reactions are only one in a million, liability settlements for those 74 kids makes it financially unsustainable to manufacture vaccines.

And so, by the mid 1980's, there were only 3 vaccine manufacturers, and only one manufacturer of the DPT (diptheria, pertussis, tetanus) vaccine. In 1984, there was such a shortage of the DPT vaccine that the CDC recommended pediatricians immediately stop giving DPT boosters, in order to ensure sufficient supplies to vaccinate infants.  Society needed to respond to the problem.

In 1986, Congress passed the National Childhood Vaccine Injury Act (NCVIA), to be funded by a tax of $0.75 per vaccine. The NCVIA was designed to improve informed consent, stabilize vaccine supplies, improve research on vaccine complications, and protect those injured by vaccines.   Additionally, vaccine manufacturers would only be subject to lawsuits for outright negligence. The Vaccine Adverse Event Reporting System (VAERS) was established to improve documentation of vaccine complications, and the Institute of Medicine established a committee to review the literature on vaccine side effects.

But most well-known was the formation of the National Vaccine Injury Compensation Program (NVICP). This program was intended to assist families suffering from a vaccine injury.  Further, the pharmaceutical companies are never involved. The general reasoning is that since our society reaps the benefits of a vaccinated population, we also bear responsibility to those injured by vaccines.

Proving a claim of vaccine damage with the NVICP is extremely difficult and requires meticulous documentation. The US government has no intention of paying damages for anything that could possibly be ascribed to any cause other than vaccine damage! On average, it takes 2-3 years to adjudicate a claim after it is filed and approximately two-thirds of cases are rejected. Despite this, the NVICP has paid damages to 3,456 people since 1989. Total costs have been more than $2.8 billion dollars.

So how does autism fit into the picture? Autism is complicated and virtually undefined.  This lack of understanding has presented challenges to the NVICP.  Here's why. Approximately 15 years ago, there were two hypotheses proposed regarding the cause of autism. One hypothesis involved the MMR, specifically the live measles component. The other hypothesis involved thimerosal, a mercury-containing preservative that was used in vaccines. The media firestorm around these two hypotheses led to a temporary but significant reduction in MMR use, a few measles outbreaks, the removal of thimerosal from most vaccines, and an explosion of research into autism. It also led to nearly 5,000 claims being submitted to the NVICP for vaccine-induced autism.

Most of these claims were grouped together into the Omnibus Autism Proceeding (OAP). In 2009, after 7 years of reviewing the research, the vaccine court ruled that the MMR does not cause autism. In 2010, the vaccine court ruled that thimerosal does not cause autism. All subsequent cases arguing that autism was caused by MMR and/or thimerosal would be summarily dismissed.

Was that the final word on autism? Not exactly. Encephalopathy is a known complication of both the DPT and the MMR vaccines.  And there are quite a few children who have received compensation for vaccine-induced neurological damage who also have a diagnosis of autism, further complicating the situation.  To date, the significance of children who have a dual diagnosis of vaccine injury and autism is a subject of heated debate and intensive scientific inquiry.

This matters because appropriate services for autistic children are expensive and when parents are desperately seeking support for their children, the National Vaccine Injury Compensation Program offers a possible solution.  Of course, the NVICP is equally desperate to deny any responsibility for children with autism, because a payout to tens of thousands of children would bankrupt the compensation fund.

When millions of dollars are at stake, human beings tend to have difficulty interpreting science with anything approaching neutrality, even when the science is very clear.  And, regrettably, the science is not clear.  Thus the continued debate, discussion and research.  

Ultimately, the lesson to take away from the past century of vaccine science is this:  When we mix together science, money, public agendas, politics, media, and liability law, things get truly convoluted...and the truth can be almost impossible to find.   

“A Community Conversation About Health and Responsibility: Vaccines and Beyond” is an ongoing series written by two close friends with a passion for improving community cohesion and building respectful relationships in a diverse world.  This article was co-created by Karen Crisalli Winter and March Twisdale.  

BLOG:  Vaccinesandbeyond.blogspot.com   

Email:  karenandmarch@rocketmail.com 

Breaking News #2: Evidence That Flu Vaccine Makes H1N1 Worse

Breaking News!

In a nutshell:  

A recent death, and additional hard-core 

science provides evidence that the flu vaccine

 actually makes you more vulnerable to H1N1.

Part of science is a willingness to look at the data, even the data that makes us uncomfortable.  

This data is very discomforting.  

It is especially disturbing because many of us have personally observed a chain of infection where influenza skipped over the vaccinated individuals, or touched them only lightly.  It is clear that sometimes the flu vaccine works as intended for some individuals.  But not always.

In fact, we're starting to see evidence that the flu vaccine may have some unexpected effects - and we are NOT just talking about reactions to the vaccine itself.  This news report begins with the story of a young boy's unexpected death, but what follows has serious ramifications for every person vaccinated by the flu vaccine who then comes into contact with H1N1...which is currently making a resurgence in the USA this flu season! 

This article contains links to multiple well-designed studies, such as:

• Infectious diseases expert Professor Peter Collignon in Australia
• Researchers in Hong Kong who conducted a double-blind placebo-controlled trial on children with the trivalent inactivated influenza vaccine with results published in the journal Clinical Infectious Diseases in 2012
• A study conducted in the U.S. and published in 2013, by microbiologist Dr. Hana Golding of the Center for Biologics Evaluation and Research at Bethesda in Maryland, who conducted a study on piglets vaccinated for H1N2, and then later exposed to H1N1

This is the kind of scientific research we need.

Even when such studies produce unexpected results.  

Because, science does that sometimes.

Link to news report and ongoing research from around the world:

http://healthimpactnews.com/2014/is-flu-vaccine-causing-increase-in-h1n1-outbreaks-5-year-old-boy-dies-from-h1n1-virus-even-though-he-was-vaccinated-month-before/

Breaking News #1: Herd Immunity Fail - New Study on Pertussis Vaccine

Breaking News!

Acellular pertussis vaccine is shown to prevent symptoms 

in vaccine recipients while NOT preventing transmission 

of the bacterium to other individuals.

AAAS article summary of how the study was set up:  The current study goes a step further and suggests that people who get the newer vaccine may still become infected and spread the germ. Tod Merkel, a microbiologist, and colleagues at the Food and Drug Administration in Bethesda, Maryland, examined response to the acellular vaccine in infant baboons, an animal that responds to the bacterium responsible for pertussis similarly to people. The researchers infected four groups of baboons, each group containing three or four babies, by anesthetizing the animals and dripping a pertussis-containing solution into their noses. One group had already received the standard three doses of the acellular vaccine; a second received the whole-cell vaccine. Members of the third group had previously had whooping cough. Those in the fourth group had not had the disease and received no vaccine before being exposed.

AAAS article summary of vaccine efficacy for the individual:  As expected, the unvaccinated baboons developed severe whooping cough, while the baboons that had been sick previously remained well, the research team reports today in the Proceedings of the National Academy of Sciences. Both groups of vaccinated animals also remained healthy. However, the germ persisted an average of 35 days in the throats of baboons vaccinated with the acellular shot, though it grew less thickly than it did in the throats of the sick, unvaccinated animals. Baboons vaccinated with the whole-cell shot harbored the germ for 18 days, and it did not grow at all in animals that previously had recovered from pertussis.

PNAS article summary of vaccine efficacy for the community:  Pertussis rates in the United States have been rising and reached a 50-y high of 42,000 cases in 2012.  Although pertussis resurgence is not completely understood, we hypothesize that current acellular pertussis (aP) vaccines fail to prevent colonization and transmission. To test our hypothesis, infant baboons were vaccinated at 2, 4, and 6 mo of age with aP or whole-cell pertussis (wP) vaccines and challenged with B. pertussis at 7 mo. Infection was followed by quantifying colonization in nasopharyngeal washes and monitoring leukocytosis and symptoms. Baboons vaccinated with aP were protected from severe pertussis-associated symptoms but not from colonization, did not clear the infection faster than naïve animals, and readily transmitted B. pertussis to unvaccinated contacts.

Resources:  All of our resources come from high quality, peer-reviewed, conservative or generally pro-vaccine sources.  We avoid mainstream news articles, which can be poorly summarized, and aim for the best core sources we can find.  

1. http://news.sciencemag.org/health/2013/11/whooping-cough-vaccine-does-not-stop-spread-disease-lab-animals
2. http://www.pnas.org/content/early/2013/11/20/1314688110.abstract

Thank You Cherry Champagne - A Story That Matters...

And now...many appreciations to Cherry Champagne for her willingness to join the conversation with her recent article, Rubella Epidemic of 1964-65, found in the November 21st issue of The Loop.

Stories matter.  Whether told, sung, written, or shown, stories inform our worldview in myriad ways.  Cherry’s story reminds us of many things.  That life should be treasured.  That severe disabilities can be tragic, but humor and curiosity can exist side-by-side with the struggles.  That parents suffer when their child’s potential is crippled, and a life is cut short.  Stories like Cherry’s serve as cautionary tales, urging us to learn from the past.  

The trouble with anecdotal stories, however, is that there are many of them, they frequently contradict one another, they are usually infused with strong emotions, and they are not subjected to rigorous scientific analysis before they are persuasively presented to an audience.  There is value in Daphne’s story.  But, if you are in the process of making a medical choice for your family, you need more than a story that pulls at your heartstrings and influences your decision in one specific direction.  You need science.  Cherry’s story about Daphne is human, real, powerful, and moving...but it is not science.

What makes science different from stories?  Simply put, science is a form of evaluation which avoids the common pitfalls of confirmation bias and preferred outcomes, allowing us to find answers that reflect data rather than our emotional expectations.  Our gut can be right.  It can also be dead wrong.  Science, like all human endeavors, is an imperfect tool.  History shows us we will err along the way, repeatedly.  However, it is still our best tool for non-biased evaluation of complex medical issues. 

As you consider your medical decisions, make space for a variety of stories in your process.  Note family medical history and pay attention to the unique aspects of your community.  Talk with your family doctor.  Consider your family’s willingness and ability to use the various tools available to protect self and community.  All these factors need to be taken into account in order to make the best decision for your child and your community.

A Community Conversation - Part 9

A Community Conversation About Health and Responsibility: Vaccines and Beyond

Part 9:  What is Autism?

Our goal this year has been to offer a non-polarizing conversation around public health.  Our strategy was to explore the issue from unusual angles.  We hoped to pull away from the divisive debate over one tool (vaccines), and broaden the conversation to include respect for diversity and acknowledgement of the grayness of this issue.  With sincere hope that we have been successful, we will now address the subject of autism.  Welcome to Part One of Three.

First, let us ask you to consider your existing ideas and beliefs about autism.  Now take a deep breath and set them aside for a moment.  Some of what we write may be a surprise to you.  We certainly encountered many surprises as we researched these articles.  

What is autism anyway? The simple truth is, we don't really know.  The diagnosis and definition of autism has been changed repeatedly over the last century and continues to be controversial.  The term was first used in 1911 to describe a symptom of schizophrenia.  Since then, the definition has bounced all over the place, always problematic in one way or another.  The current strategy is to lump a wide variety of conditions under the broad umbrella term Autism Spectrum Disorder.  This diagnosis now covers a bountiful cornucopia of behaviors, traits, severities, age of onset, and outwardly notable symptoms.  The narrowest definition we could find on the CDC website, is “ASDs are a group of developmental disabilities that can cause significant social, communication and behavioral challenges.”  How’s that for broad? 

Why does this matter?  Because the rates of autism are going up.  How much?  We’re not sure.  The CDC has created a campaign called “Learn the Signs. Act Early.”  This is an active effort to screen every child so that they will be eligible for services.  Currently, 1 in 88 children is being diagnosed with ASD. That's more than 1.1% of the population.  

But what does a diagnosis of ASD actually mean?  Our current ASD diagnosis is just as broad and non-specific as when people used to be diagnosed as having “a fever.”  Malaria, a raging staph infection, and heat stroke can all cause a fever.  Any fever can be brought down with an ice bath, but that only treats the symptom.  The ice bath may cure the heat stroke patient, but will only offer temporary benefit to the other patients.  The patient with the staph infection might be cured with a specific antibiotic, but it’s hard to research antibiotic efficacy if some of patients in your fever study actually have heat stroke.  We encounter similar problems when researching autism treatments.  Various treatments provide varying benefit to various individuals and we can neither predict nor understand why.     

Over the last fifteen years, there has been an explosion in autism research.  This is largely thanks to the dedicated efforts of parents who have tirelessly advocated for their own children.  With the CDC joining the effort, autism research is getting much needed funding and attention.  More importantly, we’re becoming increasingly open-minded about what questions we ask.  Is autism genetic?  A response to environmental factors?  A misdiagnosed brain injury?  A misdiagnosed allergy?  A persistent infection in the gut?  A problem with the human microbiome?  An aspect of human diversity?  

All these uncertainties are a normal part of the ongoing, scientific process.   We’ve currently housed a wide continuum of conditions under the term Autism Spectrum Disorder, but this is only a temporary solution.  In the years to come, through rigorous research and with a little luck, we will expand our understanding and refine our definitions.  Hopefully this will also lead to effective treatment and prevention options.  

Of course money, liability, and politics complicate everything.  This will be the focus of our next article.  

[Note:  We removed the last section of this published article about Cherry Champagne's contribution to the conversation and posted it separately, as it covers a different subject.]

“A Community Conversation About Health and Responsibility: Vaccines and Beyond” is an ongoing series written by two close friends with a passion for improving community cohesion and building respectful relationships in a diverse world.  This article was co-created by Karen Crisalli Winter and March Twisdale.   BLOG:  Vaccinesandbeyond.blogspot.com   Email:  KarenandMarch@rocketmail.com

It's all over the news! Have you heard about...

...the fascinating new study...regarding the efficacy of the 

acellular pertussis vaccine in baboons?  

Abstract of Actual Study:  http://www.pnas.org/content/early/2013/11/20/1314688110  

Relatively Good Article Referring to the Study:  http://news.sciencemag.org/health/2013/11/whooping-cough-vaccine-does-not-stop-spread-disease-lab-animals

For immediate perusal, here is the article found at ScienceMag.org.

The current vaccine for whooping cough, or pertussis, may keep you or your baby (1) healthy, but it may not stop either of you from spreading the disease, a new animal study suggests. Baboons can harbor and spread the disease even after receiving the vaccine, researchers have found. The study adds to growing evidence that the acellular pertussis vaccines, in which only parts of the pertussis bacterium are injected into the bloodstream to elicit a protective immune response, are not as good at controlling the disease as older, whole-cell vaccines were. However, a vaccine manufacturer argues that it's too early to conclude that a similar effect occurs in humans. 

Pertussis starts out like a normal cough but causes severe coughing fits and can be lethal to infants. By the time of diagnosis, it is often untreatable with antibiotics.  Historically associated with the slums of pre-World War II Europe and America, the disease has made a powerful resurgence in recent years. The United States alone experienced about 50,000 cases of pertussis last year, with 18 deaths, according to the Centers for Disease Control and Prevention. The increase could be due in part to more sensitive tools to diagnose pertussis that were widely introduced in 2010, or to pockets of children whose parents oppose vaccination. However, previous research also indicated that immunity in people vaccinated with the acellular vaccines, introduced in the 1990s, is less long-lasting than in users of the older, whole-cell vaccine.

The current study goes a step further and suggests that people who get the newer vaccine may still become infected and spread the germ. Tod Merkel, a microbiologist, and colleagues at the Food and Drug Administration in Bethesda, Maryland, examined response to the acellular vaccine in infant baboons, an animal that responds to the bacterium responsible for pertussis similarly to people. The researchers infected four groups of baboons, each group containing three or four babies, by anesthetizing the animals and dripping a pertussis-containing solution into their noses. One group had already received the standard three doses of the acellular vaccine; a second received the whole-cell vaccine. Members of the third group had previously had whooping cough. Those in the fourth group had not had the disease and received no vaccine before being exposed.

As expected, the unvaccinated baboons developed severe whooping cough, while the baboons that had been sick previously remained well, the research team reports today in the Proceedings of the National Academy of Sciences. Both groups of vaccinated animals also remained healthy. However, the germ persisted an average of 35 days in the throats of baboons vaccinated with the acellular shot, though it grew less thickly than it did in the throats of the sick, unvaccinated animals. Baboons vaccinated with the whole-cell shot harbored the germ for 18 days, and it did not grow at all in animals that previously had recovered from pertussis.

In another experiment, two baboons that had received acellular vaccines were exposed to whooping cough germs and then each was put in a cage 2 days later with previously unexposed baboons. In both cases, the vaccinated animals transmitted the germ to their cage mates, who developed pertussis. Follow-up studies showed that animals vaccinated with the acellular shots did not generate sufficient numbers of a particular variety of white blood cell to fight the pertussis infection as well as those receiving the older vaccine.

The researchers conclude that a new vaccine may be needed to provide so-called herd immunity, the ability of a community to stop an infection from spreading, and protect vulnerable babies from pertussis. “There's a difference between protecting individuals from illness and bringing down the incidence of pertussis in the population,” Merkel says. “To do both we may need a different vaccine.”

Sanofi Pasteur of Swiftwater, Pennsylvania, which makes one of the two acellular pertussis vaccines used in the United States, issued a statement cautioning that the study was not designed to evaluate the extent to which vaccination reduced transmission. “It cannot be said with certainty that these findings are directly applicable to humans,” the company said it its statement.

But other scientists applauded the work. “This is a very strong paper, even though it is a small sample,” says James Cherry, a vaccinologist at the University of California, Los Angeles, who was not involved in the study. Cherry argues that the efficacy of the acellular vaccines in trials held in Europe and Africa in the 1990s appeared high because case definitions did not count people with mild infections. The acellular vaccine was introduced because of public concerns and lawsuits arising from the whole-cell vaccine, which sometimes caused high fever and even seizures.

As for the claim that the new result may not be applicable to people, Merkel notes that, for ethical reasons, it may be difficult to duplicate the study in humans, as that would require purposefully exposing experimental subjects to a 3-month bout of pertussis.