Posted tagged ‘immunization’

Pertussis is making a comeback – what’s the best protection?

June 12, 2019

The Pediatric Insider

© 2019 Roy Benaroch, MD

Pertussis is also known as “whooping cough”, or sometimes “the 100 day cough”, or sometimes “DAMMIT WHY CAN’T I STOP COUGHING?!”. It is truly miserable. In adults and teens, three months of coughing – and I mean serious, loud, hard coughing, sometimes until you break a rib, vomit, or pass out – is not fun. Young babies, instead of coughing their little heads off, sometimes just stop breathing.

Unfortunately, it’s making a comeback. Both national statistics and our experience at my offices are showing increasing numbers of pertussis cases. Pertussis had become very uncommon with widespread vaccination by the 1980s. Why is it back?

(Aside: about 25 years ago, in my very first month of training as a pediatrician, I was taking care of a newborn in the emergency department who stopped breathing. Completely. Just stopped. Turned blue and floppy. I was terrified, but kept my cool and performed mouth-to-mouth resuscitation. The baby did fine. Later, my attending told me to never use my mouth on a baby – there was resuscitation equipment literally hanging on the wall behind me that I didn’t think to use. Oops. Later, I found out the baby had pertussis.)

The first pertussis vaccine was developed in the 1930s, and in the 1940s it was combined with tetanus and diphtheria vaccines to create the “DTP” vaccine. This was very effective at preventing pertussis, but it was quite “reactogenic”. DTP commonly causing fevers and sometimes febrile seizures (which, by themselves, are harmless – but really scary.) There were cases of encephalitis and dramatic developmental regression seen, too, though it’s become clear since then that these were cases of the genetic condition Dravet Syndrome, which unfortunately starts showing symptoms around the time DTP was given. The quest was on for a pertussis vaccine that caused fewer fevers, and a newer, more purified “acellular” DTaP was developed.

After extensive studies showed that the DTaP was effective and caused fewer fevers, the acellular vaccine replaced the older, “whole cell” vaccine in the US and many other developed countries in the 1990s. And, at least at first, things seemed to go well. Pertussis cases remained low.

But we’ve seen a steady increase in cases over the last 10-15 years. Part of that could be ascertainment bias – there are newer, better, and faster tests for pertussis that have come into wider use, and doctors think about testing more kids for pertussis now that’s clear there are more cases. That doesn’t explain all of the increase.

A study published this week in Pediatrics has helped clarify what’s going on. About a half million children managed at the huge Kaiser Permanente system in Northern California were studied, looking at their pertussis vaccine status and the rates of proven cases of pertussis in the group. Almost 750 cases of pertussis were documented in these children from 2006-2017, revealing some important conclusions:

  • Pertussis risk, overall, was 13 times higher in unvaccinated versus fully-vaccinated children. The vaccine is protective.
  • Still, 80% of the cases occurred in children who had received the full set of doses. Pertussis immunity dropped off over time – and the longer since the most-recent dose, the more at-risk a vaccinated child became.

So what should we do?

First: widespread, continued universal DTaP vaccinations in infancy and Tdap boosters for preadolescents is still a good idea. It is far better than not vaccinating. The Kaiser data clearly shows vaccinated individuals are at lower risk. Since one of the highest risk groups for severe disease is newborns, vaccinating pregnant women is a key strategy. Though maternal pertussis immunity after Tdap doesn’t last long, it does last long enough to transfer protective antibody to the unborn baby, providing crucial protection during the first few months of life.

But we clearly need a better vaccine and other strategies to provide better, more-lasting protection. Alternatives are being studied, including a nasal-spray pertussis booster and new, adjuvanted vaccines that can hopefully provide more-lasting protection safely. New vaccines take many years to study, so don’t expect anything on the market soon.

In the meantime, we need to do the best we can. Make sure you and your children are fully vaccinated against pertussis, and follow the recommendations for all vaccines. We need to be a better job developing better tools, but in the meantime we could be doing a better job using the tools we’ve already got.

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Chicken pox vaccine prevents shingles, too

June 10, 2019

The Pediatric Insider

© 2019 Roy Benaroch, MD

A study published today in Pediatrics confirms good news about routine chicken pox vaccination in children: it also prevents shingles. Smaller studies had seemed to show this was likely, and this huge new study of over 6 million children nails it down. And: the benefit seems to apply to all of our children, even those unable to be vaccinated.

A little background: chicken pox and shingles are both caused by the same virus, named “Varicella Zoster Virus”, or VZV. When people first catch this very contagious illness, they get a painful and itchy rash accompanied by fever – that’s chicken pox. It’s a miserable experience – I remember when I had it, a summer long ago – that can also lead to complications like pneumonia, life threatening skin infections, and encephalitis. Even when you’ve recovered from chicken pox, the sneaky devil-virus hides in your nerve cells, waiting for an opportunity to swing back into action. And that recurrence of symptoms is what’s known as shingles, or “zoster” – a very uncomfortable rash that can leave lasting pain that can very difficult to control. Zoster especially likes to pop back up when you’re already sick or having other health problems, just to give you an extra poke in the eye.

“Remember me?” VZV says. “Have some pain!”

A vaccine to prevent VZV infections was developed in Japan in the 1970’s. It was specifically targeted at first for children undergoing chemo for leukemia, because so many of them were dying of overwhelming VZV infections (in people with suppressed immune systems, primary or recurrent VZV infections can be devastating.) The vaccine was very successful in saving lives and preventing misery in these children, which led to more-widespread testing in healthy kids and the adoption of widespread chicken pox vaccinations in the 1990’s. Later, it was shown that two doses worked better than one, and the current guidelines in the US recommend two doses be given routinely to all children starting at 12 months of life. This protects not only the children who get the vaccine, but their families and their communities, including people who can’t be vaccinated and children and adults on chemo or other medicines that suppress their immune systems (By the way: there are a lot of these people around. Including some of your friends and their children. Immune-suppressing “biologic” agents are now used routinely to improve the lives of people with psoriasis, Crohn, rheumatoid arthritis, and many other diseases. You’ve got friends, neighbors, and coworkers on these medicines. You can help protect them.)

A fair question to ask: do routine chicken pox vaccines also prevent VZV from recurring – that is, do they prevent shingles? Those studies in immunocompromised children showed it definitely did, but we needed years of data to prove that it was also effective in the broader population, because shingles may occur many years after chicken pox. And now, we’ve got solid data.

This study was done at six sites in the US, mostly in California, following the medical records of 6,372,067 children for 12 years. The results are impressive. First: rates of zoster/shingles dropped dramatically in the whole population, by about 50%, over the 12 years. Even in children who weren’t vaccinated, zoster is boing prevented by the use of this vaccine. But the effect was much larger children who did get the vaccine, and larger still among children who got the full course of two doses rather than one.

Vaccine science is always evolving, and important studies continue – there is always more to learn. All of the good evidence so far had shown that this vaccine was preventing both chicken pox and shingles, and this long-term, huge study adds to the evidence. Make sure your children and your family are up to date on their vaccines, including this chicken pox vaccine, to best protect yourself and your community. We’re all in this together, folks. Do the right thing. Vaccinate.

 

It’s time to rethink pertussis prevention

February 8, 2016

The Pediatric Insider

© 2016 Roy Benaroch, MD

A large, sobering study published in the March, 2016 edition of Pediatrics illustrates just how far we still need to go to effectively control pertussis.

Pertussis, also known as ‘whooping cough’, is a serious illness. Older children and adults get to enjoy a horrible cough for about three months—a cough that sometimes makes people vomit, break ribs, or pass out. Seriously. You haven’t seen a “bad cough” until you’ve seen the cough of pertussis. Worse: in little babies pertussis can cause breathing problems, seizures, and death. Though its caused by a bacteria, antibiotics (unless given very early) are ineffective at reducing the length or severity of pertussis. Prevention, in this case, is worth far more than a pound of cure.

Up until the mid-1990s, infants and children routinely received the whole-cell DTP vaccine (DTP = diphtheria, tetanus, pertussis.) It worked at preventing all three of these diseases, but had a relatively high rate of side effects, mostly fevers. Many of the suspected more-serious side effects (like encephalopathy and seizures) are now known to have been caused by genetic conditions, not the vaccine, but nonetheless parents and doctors alike welcomed a newer vaccine, the acellular DTaP. This newer vaccine, which replaced DTP in the United States by around 1998, caused fewer fevers, and was thought to cause fewer serious reactions, too.

The problem is that it just doesn’t work as well. And as the first generation of infants to get an all-DTaP series starts to go through adolescence, we’re starting to see the unintended consequence of that vaccine change.

In the current study, researchers used a huge database of information from the Kaiser Permanente system of Northern California. We’re talking solid, big-data research, here, the kind of study that requires consistent and reliable data across a huge set of patients. In this case, about 3.5 million patients across 55 medical clinics and 20 hospitals, using centralized labs and an integrated medical records system. If health things happen to this population, Kaiser knows it.

In 2010 and again in 2014, California experienced large epidemics of pertussis. A total of 1207 cases were among Kaiser teenagers, all with complete records of their pertussis vaccination status. And the results aren’t anything to be happy about. In the first year after an adolescent pertussis (Tdap) booster, the vaccine was about 70% effective in protecting against pertussis. Not great, but not terrible, either – until you look a few days down the road. The vaccine effectiveness drops off dramatically, year after year, down to only about 9% by four years after receipt of the vaccine.

Why does Tdap seem to provide such poor protection—much worse than was seen in the original licensing studies? It’s a generational change, and it goes back to the shift from DTP to DTaP in the mid-1990s. By now, these teens in California are old enough to have received DTaP, not DTP, as infants. The authors looked at the specific ages of pertussis cases during the 2010 and 2014 outbreaks, and the trends support the conclusion that teens who received DTP as infants get good, lasting protection from Tdap; teens who got DTaP do not.

Now what? Clearly, we need a more-effective vaccine, perhaps even resuming the use of whole-cell pertussis vaccine, at least for the earlier doses. But in the meantime, we have to do the best we can with what we have. Vaccinating pregnant women with Tdap does effectively prevent pertussis in their babies, especially when they’re the youngest and most-vulnerable. And adults (who got DTP as children) should get Tdap boosters too, to protect the children around them. Another idea (floated by the study authors) is to use Tdap in teens not as a routine booster, but as a strategy to control local outbreaks, taking advantage of the higher effectiveness seen for the first year after vaccination.

I don’t have the answers. I’m not happy to see studies like these, but examining and re-examining vaccine safety and effectiveness is something we need to continue doing, with an open mind, relying on solid evidence. Bottom line: with pertussis, we need to do better.

Whooping crane

Measles vaccine: A real immunity super-booster

October 29, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

What if there was an intervention that could reduce a child’s risk of death from infection—from any infection—by half? And that one intervention’s immune-boosting power lasted 2 or 3 years. It’s also very safe, with a very small risk of any serious side effects.

Pat yourself on the back. Your child has probably already had it, and your entire community is getting benefit from fewer circulating infections.

A recent study published in Science looked at long-term changes in immunity following measles vaccination in populations worldwide. It’s known that measles infection put people at risk for other infections for several weeks or months afterwards – natural infection seemed to suppress the immune system. Using data correlating vaccinations, measles cases, and infectious disease deaths, the authors found that the immune suppression had a much more serious and lasting impact than had been thought. For two to three years after natural measles, the all-cause infectious mortality spiked upwards. Measles vaccination, in other words, doesn’t just prevent measles deaths—it prevents deaths from any infection. For years.

The effect is striking in its intensity. Overall, when measles was common years ago, it accounted for about half of all deaths from infection (combining the direct effect of measles infection itself with the immune suppressive effect.) In some of the most resource-poor countries, it probably accounted for up to 90% of all infectious deaths. Think about that. One vaccine, preventing all of those deaths. The authors only looked at mortality—if you consider other morbidity, hospitalizations, costs, and misery, the positive effect of measles vaccinations would be much, much higher.

Boosting immunity doesn’t just help the individual child. The entire community is protected when the risks of infection drop, including the risk to newborns and elderly people, or people who are already sick.

Don’t be fooled by the fake immune-boosters—the colon cleanses, the “Airborne”, the pills and potions pushed by the multi-billion dollar supplement industry. Real immune boosting does not rely on magic. Get enough quality sleep, eat a healthy diet, get some exercise, and take reasonable precautions like washing your hands and avoiding sick people. And, please, make sure you and your children have received all of the recommended vaccines. Protect yourself, protect your kids, protect your communities. Vaccinate!

A few surprising vaccine myths – Betcha didn’t know!

February 23, 2015

The Pediatric Insider

© 2015 Roy Benaroch, MD

Myth 1: Vaccines work by preventing disease in individuals who are vaccinated.

Nope, that’s not actually true—it’s quite wrong, but in a subtle way. And a misunderstanding of this concept, I think, has led to a lot of mischief. If people understood how vaccines really work, how they can best protect us from disease, it might help overcome some skepticism.

Vaccines do indeed prevent diseases in individuals, but that’s not how they accomplish their most important job. See, vaccines can’t be given to every individual—babies can’t get MMRs until they’re 12 month old, for instance, and many people on chemo or after transplants can’t get them at all. And even the absolute best vaccines don’t work all the time. Two doses of MMR gives 99% of recipients lifelong immunity from measles, but if you’re at Disneyland along with 40,000 other visitors that day, it means about 400 vaccinated people (1%) are not immune. That’s not a slam on the vaccine—it’s just that any medical intervention is imperfect.

So if vaccines don’t work by protecting vaccinated individuals, how do they work? By protecting populations. In a highly vaccinated population, even if measles pops up it’s got nowhere to go. If only a small number of people aren’t immune, it’s unlikely anyone else will catch it—and that means measles cannot spread, and everyone is protected. Not just the immunized, everyone. This is called “herd immunity”, and it’s the real way that vaccines work.

Vaccines aren’t about protecting just you, or your children, or just the person who gets the vaccine. Vaccines are about protecting all of us, even the babies, and the ill, and the unlucky few in whom vaccines don’t work. We’re all in this together. Maybe you’ll be the next in the neighborhood with a newborn, or maybe it will be your sister who’s diagnosed with lymphoma. Make sure your whole family is vaccinated to keep all of us safe.

 

Myth 2: Children are required to be vaccinated.

Nope. Children are required to be vaccinated in order to attend public school, just like you’re required to have a driver’s license if you want to drive. But you don’t have to get your children vaccinated as long as you make other arrangements for their education.

Even then, there are plenty of exemptions. Every state supports exempting children with legitimate medical contraindications to vaccines; almost all states support “religious objections” (though there is no common religion that’s against vaccines); many states also offer “personal belief” exemptions, too.

No government authority is forcing anyone to vaccinate, and no children are being taken away from parents who don’t vaccinate.

 

Myth 3: Vaccination, inoculation, immunization—they all mean the same thing.

In common usage, yes. But technically, they’re different.

Inoculation initially referred specifically to the historical practice of rubbing the skin of a healthy person with a little bit of crust from a smallpox victim. It was known that this could often induce a mild case of smallpox, which would protect the person from a full-blown, deadly case later. These procedures were fairy widely known especially in England in the 1700s, and remained in widespread use for hundreds of years. The word inoculate comes from the Latin root for ‘eye”, referring to the practice of grafting a bud from one plant to another.

Edward Jenner later started using scabs from cowpox to “inoculate” a milder disease, which was close enough to prevent smallpox, too. It’s thought that his inspiration was the fair, unblemished skin of English milkmaids—they universally caught cowpox as an occupational hazard, so rarely caught the disfiguring smallpox. “Vaccine” comes from the Latin word for cow, either referring to cowpox or perhaps to those fair-skinned milkmaid workers. For a while, the term “vaccination” referred only to using cowpox crusts to prevent smallpox, but later the term became more generalized to include the procedures developed by Louis Pasteur to prevent chicken cholera and anthrax.

Immunization was a later term that broadly referred to both using live infectious particles to induce active immunity, or using non-infectious toxins or other proteins. Typically, now, most of us use the terms vaccine, vaccination, and immunization pretty much interchangeably. Next time your children get one, thank a cow!

Infection Report 4: Two newcomers and the importance of paying attention

October 9, 2014

The Pediatric Insider

© 2014 Roy Benaroch, MD

While Ebola makes the headlines and influenza prepares its yearly visit, two other “new” infections have been brewing this summer. We’re still got a lot to learn about “the new respiratory virus,” AKA enterovirus D68, and whatever seems to be causing cases of paralysis in 9 kids in Colorado. It’s even possible that these two infections are the same. These infections are coming to light because hospitals and public health officials stay on the lookout for new patterns of disease and infections. It’s not complicated, and it’s really not rocket science. It’s all about paying attention.

Earlier this year, hospitals first in Illinois and Missouri reported an unusual spike in ER visits and hospitalizations for respiratory symptoms, including cough, wheezing, and difficulty breathing. Often, children with this infection became very sick very rapidly, requiring hospital or ICU-level care very shortly after the onset of symptoms. Most, but not all, affected individuals had pre-existing lung problems, mostly asthma. Though routine testing for a specific agent still isn’t widely available, laboratories were able to identify a specific viral cause, an “enterovirus” named D68. That virus has been around since at least 1962, but until this year hadn’t caused widespread infections. It’s probably spread throughout the United States, and continues to contribute to many hospitalizations.

Many children (and adults) with this infection probably have mild symptoms, indistinguishable for any other viral “cold”, but some go one to become seriously ill. By the way, that’s true for almost all ordinary cold viruses—though most people sail through those infections just fine, every once in a while an ordinary cold virus makes someone very, very ill. This new enterovirus isn’t really that different from many other respiratory viruses, but it’s newly widespread and seems to have a disproportionately high rate of complications.

Or maybe it is kind of different, after all. We’re also hearing reports out of Colorado of a new kind of illness, one that looks like an infection, that’s caused flaccid paralysis in at least 9 children (actually the CDC is investigating about 23 reports, though it’s not yet clear if all of these are the same condition.) Many of those children seem to have had a respiratory illness about 2 weeks prior to the onset of the paralysis. MRI scanning is showing changes in the part of the spinal cord that controls motor functioning, and in some ways the clinical presentation and MRI findings look similar to an old infection, poliomyelitis. But specific tests for polio virus have been negative.

Here’s an theory: this respiratory virus D68 and polio virus are related—they’re both from a large, diverse family of viruses called “enterovirus.” These viruses typically cause summer infections, and different kinds of enterovirus can cause disease of the gut, lungs, liver, nerves, skin—all sorts of things.  About half of the Colorado 9 children have tested positive for D68. That’s not definitive—that doesn’t mean D68 is causing the paralysis—but it’s certainly suggestive and interesting. It is possible that these two new things, the respiratory virus and the paralysis, are actually being caused by the same infection.

We’ll be learning more about these infections in the coming months. For now, the best steps available to protect your family are common sense things: wash hands, stay away from sick people, don’t touch your face, and beware of signs of bad respiratory disease. Though there are no vaccines for these new infections yet, you can prevent the return of polio and the widespread sickness of influenza with current, safe, effective immunizations. Hospitals, doctors, and staff at hospitals in the midwest did a great job in identifying these new problems and alerting public health officials to begin their investigation. Our health depends on all of us, together, paying attention to and confronting health threats like these.

Next: What you really need to worry about

Dr. Bob Sears says skipping vaccines is not good for public health

September 9, 2014

The Pediatric Insider

© 2014 Roy Benaroch, MD

This weekend, The Los Angeles Times reported on California pediatrician Dr. Bob Sears’ role as a favorite among vaccine-fearing parents. What he tells them is absolute nonsense that he has freely admitted he made up in a Reddit interview. Now he’s let a little more honesty shine through. He told the reporter:

“I do think the disease danger is low enough where I think you can safely raise an unvaccinated child in today’s society,” he said. “It may not be good for the public health. But … for your individual child, I think it is a safe enough choice.”

I had wondered: is it possible that a board-certified pediatrician, one from a family of influential and well-known children’s health experts including Dr. William “Attachment Parenting” Sears and Dr. Jim “The Doctors” Sears, could really believe the idiocy in his own book? Now we know. Dr. Bob Sears says screw public health, screw everyone else’s children, screw your neighbors and their families. It’s fine if you skip your child’s vaccines, because for your child the risk isn’t great. That may not be good for the public, Bob says, for all of those other idiots out there—we know if people start skipping vaccines the disease will surge back. But for your snowflake, well, it’s OK. You can even picture him winking when he says it.

This is just despicable. Mendacious, vile… I’m running out of adjectives, here. Dr. Bob thinks his own special pals, his patients, the suckers who buy his books, they don’t need their vaccines—they can just hide in the herd, as long as the rest of us get our kids vaccinated. His white, affluent, Orange County kids can’t be bothered with needles. Sure, it’s no good for public health, but public health isn’t something his parents need to think about.

Dr. Bob freely regurgitates long-disproved anti-vaccine canards throughout his laughably mis-named The Vaccine Book: Making the Right Decision for Your Child. The book has sold well. He’s telling people exactly what they think they want to hear, blaming all sorts of ills on vaccines, fueling fear and anxiety and a mistrust of every legitimate health authority on the planet. They’re all wrong, he says, the CDC and the IOM and every county health officer and every single country’s health ministries and all of the pediatricians, family medicine docs, infectious disease specialists, and everyone else who’s invested their careers in protecting the public health. We don’t need no stinkin’ evidence.

He’s making oodles of money off of your fear, while freely admitting that what he’s doing is no good for the public health. Don’t forget: the public is you, your children, your family. We’re all in this together, sharing our planet and sharing these infections. You can help keep your children and communities safe by making sure your kids are vaccinated. Or you can join the “me first, screw you” brigade led by Dr. Bob.