Tag: waning immunity

Mumps on the USS Fort McHenry

Like measles, we are seeing more mumps these days.

“Beginning in 1991, the military services implemented universal recruit immunization with a single dose of MMR vaccine, regardless of prior vaccination history. Shortly thereafter, and informed by the results of population serosurveys, the Air Force transitioned to a policy of targeted MMR vaccination, limiting the administration of MMR vaccine to recruits lacking serologic evidence of immunity to measles or rubella. With recent outbreaks of mumps, concerns have arisen that the practice of not specifically screening for mumps immunity in determining the need for MMR vaccine could lead to a relative increase in mumps risk among military recruits subject to screening. “

Eick et al on Incidence of mumps and immunity to measles, mumps and rubella among US military recruits, 2000–2004

Unlike measles, the MMR vaccine provides good, but not great protection against mumps.

And although military recruits are screened to see if they have low titers for measles and rubella, they still aren’t screened for mumps. The theory is that if their measles and rubella titers are low, then their mumps titer will be low too and they will get an MMR vaccine. Of course, this misses some who just have a low mumps titer, possibly an effect of waning immunity.

Mumps on the USS Fort McHenry

And that’s why we have been seeing mumps outbreaks on college campuses and most recently, on a Navy ship, although that isn’t a reason for everyone to go out and check their titers.

A tiny handful of measles outbreaks? There have been over 700 cases in the US during the past two years! There were only 37 cases in 2004.

Robert F. Kennedy, Jr has a lot to say about mumps…

He says that mumps outbreaks have devastated fully vaccinated populations at Harvard, Temple, Syracuse, Louisiana State, IU, and the U of Missouri…

And that mumps “epidemics” haven’t been covered by the media, because they don’t want to embarrass Merck…

Why won’t the media cover the mumps outbreaks! Oh, wait…

He also seems to think that these mumps cases have caused a national security threat

Is any of this true?

The simple fact that you can find a ton of stories in the media about the mumps outbreaks (they are not epidemics) gives you a good clue that they aren’t.

What about the quarantined sailors on the USS Fort McHenry?

That is true, but consider that only 27 of 700 of them have gotten parotitis, presumed to have been caused by mumps.

While you would expect that no one would get mumps or any other vaccine-preventable disease these days, that is just under 4% of those on board the ship.

What would have happened in the pre-vaccine era?

Although deaths were rare, mumps caused a lot of considerable loss of service and sick time in the military in the pre-vaccine era.
Although deaths were rare, mumps caused a lot of considerable loss of service and sick time in the military in the pre-vaccine era.

A whole lot more people would have gotten sick!

In the pre-vaccine era, although mumps was supposed to be a common childhood illness, about 1/3 to 1/2 of military recruits had never had mumps.

That meant big outbreaks of mumps that were hard to control, unlike what we see today.

“This article reports a recent public health response to 3 imported mumps cases occurring at Fort Campbell, Kentucky, that resulted in a contact investigation for 109 close contacts across varied settings. No secondary mumps cases were identified.”

Public Health Response to Imported Mumps Cases – Fort Campbell, Kentucky, 2018

Instead, not only do fewer people get sick during mumps outbreaks these days, but fortunately, they have fewer complications.

What kind of complications?

Mumps causes kids to have fever, puffy cheeks, and a painful, swollen jaw.
Mumps causes kids to have fever, puffy cheeks, and a painful, swollen jaw.

In addition to a swollen jaw, mumps is known to cause orchitis, aseptic meningitis, oophoritis, pancreatitis, and encephalitis.

“Risk was reduced for hospitalization, mumps orchitis and mumps meningitis when patient had received 1 dose of measles, mumps, and rubella vaccine. The protective effect of vaccination on disease severity is critical in assessing the total effects of current and future mumps control strategies.”

Young et al on Mumps Complications and Effects of Mumps Vaccination, England and Wales, 2002–2006

Fortunately, those complications are reduced when you get vaccinated. And so are your risks of actually getting mumps in the first place!

“This study demonstrates a significant preventive effect of two-dose vaccination against mumps complications (orchitis, meningitis, or encephalitis) and hospitalization for mumps.”

Orlíkováet al on Protective effect of vaccination against mumps complications, Czech Republic, 2007-2012.

Kennedy doesn’t mention a protective effect of the MMR vaccine, does he?

Remember, vaccines aren’t perfect, but even those that don’t work as well as the others still protect you from many of the worst complications and are much better than getting the disease naturally.

Mumps was often described as one of the top diseases that incapacitated soldiers in the prevaccine era.
Mumps was often described as one of the top diseases that incapacitated soldiers in the prevaccine era.

Vaccines are safe, with few risks, and are obviously necessary.

Is the mumps vaccine a national security threat? The only threat are the folks who continue to push anti-vaccine misinformation.

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Why Does the BMJ Post Anti-Vaccine Propaganda?

Getting something posted in a medical journal is a big deal?

Getting something posted in The BMJ? Not so much…

Why Does the BMJ Post Anti-Vaccine Propaganda?

Oh, I’m sure it used to be, as they are one of the world’s oldest general medical journals, going back to 1840.

“Reader feedback online is actively encouraged in the form of Rapid Responses were introduced in 1998, and 20 years later, had generated 115,000 fully-moderated responses.”

History of The BMJ

The thing is, they allow just about anyone to post these Rapid Responses, without making it very clear that they aren’t in a peer reviewed section of the journal.

What’s wrong with this Rapid Response?

  1. The Federal government isn’t issuing any kind of quarantine in this matter, the county is, so why would it be an issue as to whether or not measles is subject to Federal isolation and quarantine law? Anyway, while there are few diseases on the list that are subject to Federal isolation and quarantine law (they do include cholera, diphtheria, plague, smallpox, Ebola, and pandemic flu, etc.) measles could be added by a Presidential Executive Order. Still, the authority to issue Federal Quarantines has rarely been used. Quarantines for measles is usually handled by states and local governments.
  2. Supposed to be protected anyway??? There are plenty of infants, children, and adults who simply can’t be directly protected by a vaccine. They are too young to be vaccinated, can’t be vaccinated because they have true medical contraindications, or could be among the very small minority for whom their vaccine wasn’t effective. They are at risk when your intentionally unvaccinated child gets measles.
  3. The vaccination rates for everyone in the Rockland outbreak is posted and is updated weekly. Only 3.8% of the folks in the outbreak are fully vaccinated.
  4. Since almost all of the folks in the outbreak are unvaccinated, that kind of busts John Stone’s last point – the Rockland measles outbreak has been caused by waning immunity and a failed vaccine. It is simply a failure of folks to vaccinate and protect their kids.

I get that The BMJ wants their “users to debate issues raised in articles published on bmj.com,” but they are simply contributing to the false balance we see in many other places if they want to allow folks to think there is a debate going on about the safety or necessity of vaccines.

More on Anti-Vaccine Propaganda in The BMJ

Making a Better Pertussis Vaccine

So we know that we need a better pertussis vaccine.

DTaP and Tdap just aren’t doing the job that they should be doing.

Whooping Cough is back, again.
Whooping Cough is back, again.

So when will we get one?

Making a Better Pertussis Vaccine

Since anti-vaccine folks are always talking about the 300 new vaccines in the pipeline, you would think that we would have had several new pertussis vaccines by now…

Unfortunately, we don’t.

What we do have is some good candidates, including:

  • new acellular pertussis vaccines, either with more antigens or an adjuvant
  • a new live attenuated nasal vaccine, BPZE1
  • new whole-cell vaccines with reduced endotoxin contents (so should have fewer side effects that then original whole-cell pertussis vaccine – DTP)

Before you get too excited, keep in mind that none of these vaccines will be available in your pediatrician’s office any time soon. Developing a new vaccine takes a lot of time.

BPZE1 has started phase 2a trials though.

What do we do until we get new pertussis vaccines?

“We should be more vigilant than we have been in the past to recognize and treat pertussis in all age groups so that transmission to young infants is reduced. Most important (although not discussed in this review) is to ensure that all pregnant women receive the Tdap vaccine between 27 and 36 weeks’ gestation with each pregnancy. Also, we should consider routinely administering Tdap vaccine every 3 years to all adolescents and adults who were primed with a DTaP vaccine.”

James D. Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines—Mistakes Made and Implications for the Future

We should keep using the pertussis vaccines we have!

Vaccines work, even when they aren’t as effective as we would like.

More on Making a Better Pertussis Vaccine

Does Getting the DTaP Vaccine Make You More Susceptible to Pertussis?

Wait, why would anyone think that getting vaccinated would make you more likely to get a vaccine-preventable disease?

Because there is a new pertussis outbreak in California and folks don’t understand how attack rates work…

Does Getting the DTaP Vaccine Make You More Susceptible to Pertussis?

We know that the latest pertussis vaccines aren’t the greatest, having issues with waning immunity.

They don’t actually make you more likely to get pertussis though, at least not relative to being unvaccinated.

“Because of linked-epitope suppression, all children who were primed by DTaP vaccines will be more susceptible to pertussis throughout their lifetimes, and there is no easy way to decrease this increased lifetime susceptibility.”

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

What the above quote that anti-vaccine folks are misusing is actually saying is that kids who got DTaP vaccines will be more susceptible to pertussis compared to those who got DTwP, the older version of the vaccine. That’s what the whole article is about!

It is not that they will be more suspecptible to pertussis vs someone who was unvaccinated.

Dr. I: Anti-vax folks are misinterpreting that statement, not understanding that it means relative to kids who got DTwP. They think that you are saying that it is the DTaP vaccine itself that makes it more likely that a child will get pertussis, in general. Even relative to someone who is unvaccinated. I know it shouldn’t be necessary, but can you provide a simple quote to clarify this?

JDC: You are of course correct. I was asked to write-up the talk that I have given many times in the US and in many other countries. In the talk, right at the beginning, I mention that today there is 20 fold less pertussis than there was in the pre-vaccine era and that illness in vaccine failures is much less severe that illness in unvaccinated children. I also remember how wrong they were 30 years ago R/E alleged reactions to DTwP.

And if you read his latest article, The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future, especially if you read more than the abstract, you discover that’s what he is saying.

But what about linked-epitope suppression?

In “linked-epitope suppression,” memory B cells out-compete naive B cells for access to the Bordetella epitopes because they are more numerous and their receptors exhibit a higher antigen affinity. Linked-epitope suppression applies as the immune response to novel epitopes is suppressed by the strong response to initial components if they are introduced together.

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

Basically, the DTwP vaccine included many more epitopes or targets for antibodies to bind to than the newer DTaP vaccine. That’s why it worked better. And you don’t get a good response to non-vaccine epitopes or antigens.

Still, you at least have some memory B cells and antibodies after getting the DTaP vaccine, which is why the idea that getting vaccinated makes you more susceptible to pertussis is silly. You are still protected, even if the protection isn’t perfect.

That’s why Dr. Cherry recommends that folks continue to get vaccinated and protected!

“We should be more vigilant than we have been in the past to recognize and treat pertussis in all age groups so that transmission to young infants is reduced. Most important (although not discussed in this review) is to ensure that all pregnant women receive the Tdap vaccine between 27 and 36 weeks’ gestation with each pregnancy. Also, we should consider routinely administering Tdap vaccine every 3 years to all adolescents and adults who were primed with a DTaP vaccine. This suggestion is contrary to that in the current Advisory Committee on Immunization Practices recommendations. However, from the data available, this approach could be expected to decrease the circulation of B pertussis in adolescents and adults. Also, Tdap should be administered to all adolescent and adults exposed to B pertussis during a school or other group outbreak.”

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

He does recommend that we work on new pertussis vaccines though.

“Future cohorts would benefit from the development and use of live vaccines and less-reactogenic DTwP vaccines.”

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

But why are we using a vaccine that doesn’t work as well as the previous vaccine we had?

“Despite the fact that in all but 2 of the efficacy trials the DTwP vaccines had greater efficacy than did the DTaP vaccines being studied, DTaP vaccines were licensed and used in many countries throughout the world; DTaP vaccines had replaced DTwP vaccines. The urgency to adopt DTaP vaccines was driven largely by antivaccine activist groups such as “Dissatisfied Parents Together.” During the rush to adopt DTaP vaccines and tetanus, diphtheria, acellular pertussis vaccines for adults (Tdap), much of the history relating to human pertussis was overlooked.”

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

But the DTwP vaccines weren’t safe, right?

“The results of a number of controlled studies between 1979 and 2004 indicated that no risk of severe neurologic disease after DTwP vaccinations existed. It was noted by myself and Shields (a pediatric neurologist) that what was being called pertussis vaccine encephalopathy was not an encephalitis-like event but, instead, the first seizure or seizures of infantile epilepsy.”

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

No, the cases of encephalopathy that were being reported were not caused by the DTwP vaccine. And neither did the DTwP vaccine cause SIDS, as was also reported at the time.

“Since 1997, the DTaP vaccination policy has created a cohort of people (the number of which is expanding yearly) who are more susceptible to repeated clinical illness with B pertussis infection than are DTwP-vaccinated children. There is no feasible way to make this cohort less susceptible.”

JD Cherry on The 112-Year Odyssey of Pertussis and Pertussis Vaccines-Mistakes Made and Implications for the Future

And now, after helping create the current DTaP vaccination policy, anti-vaccine folks want to scare folks away from using the vaccine. Don’t let them. Don’t skip or delay this vaccine and leave your kids susceptible to getting diphtheria, tetanus, and pertussis.

More on Does Getting the DTaP Vaccine Make You More Susceptible to Pertussis?