Tag: Tdap

When Was the Last Case of Diphtheria?

Believe it or not, measles isn’t the only vaccine-preventable disease that is still around.

While you likely aren’t too surprised about the flu deaths and the cases of meningococcal disease, did you know that kids still get Hib, babies still get hepatitis B, and that there were three cases of human rabies and a case of diphtheria in the United States last year?

When Was the Last Case of Diphtheria?

Yes, diphtheria.

Diphtheria strikes unprotected children.

That’s despite the fact that the diphtheria vaccine has been around for over 100 years, long before it was combined with the first whole cell pertussis vaccine and the tetanus vaccine to form the DPT vaccine.

A vaccine that helped control respiratory diphtheria, which could lead to the formation of a pseudomembrane in a child’s airway, giving diphtheria the nickname of the “strangling angel.”

The last big outbreaks of diphtheria in the United States occurred in the 1970s, although sporadic cases had continued since, albeit at lower and lower levels each year. Eventually, endemic respiratory diphtheria was declared eliminated in 2009.

Still, we know that there have been some recent cases of diphtheria in the United States.

In April of 2014, a teen from Montgomery County, Ohio developed diphtheria.

And again in April of 2018, someone in Oklahoma developed diphtheria.

Why do we care about a few isolated cases?

Because we know how quickly diphtheria can come back if we stop vaccinating our kids!

Just look at what is happening in many other countries that once had these diseases under good control:

  • a 22-year-old unvaccinated women who died in Australia (2011)
  • an unvaccinated 3-year-old who died in Belgium (2016)
  • a family that became infected in South Africa in which at least one child died (August 2017)
  • at least 7 cases of diphtheria in Ukraine (2018)
  • an unvaccinated man in Australia who died (2018)
  • a case in Canada (2018)
  • 8 cases and 3 deaths in Columbia (2018)

Not to mention the large number of diphtheria deaths in Yemen, Venezuela, Haiti, and among Rohingya refugees.

Let’s not bring these diseases back. Vaccines are safe, with few risks, and obviously necessary.

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Are the Tdap and DTaP Vaccines the Same Thing?

You have probably already figured out the Tdap and DTaP aren’t the same vaccine, after all, if they were, why would they have different names, right?

Are the Tdap and DTaP Vaccines the Same Thing?

I bet you don’t know the difference between the two vaccines though.

Yes, they both are both combination vaccines that protect against diphtheria, tetanus, and pertussis.

The difference is that one (DTaP) is used as the primary series for infants and younger children (age 6 years and under) and the other (Tdap) is given to older children (age 7 years and above), teens, and adults.

Okay, that’s not the only difference.

The DTaP vaccine actually contains more diphtheria and pertussis antigens than Tdap, which is why it has the capital “D” and “P” in its name. The amount of tetanus toxoid antigens are about the same in both vaccines.

So Tdap contains the same amount of tetanus toxoid, plus a reduced amount of diphtheria and acellular pertussis antigens, as compared to DTaP.

While you would think that older children and adults would get the vaccine with the higher amount of antigens, since they are bigger, that’s not how this works. Vaccines typically start working at the injection site, so body size isn’t a key factor in determining the amount of ingredients.

As a booster dose of vaccine, the lower amount of antigens works just fine and helps reduce the risk of side effects from repeated doses that you might get with higher antigen counts.

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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.

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Did the FDA Admit That the Government Is Recommending Untested, Unlicensed Vaccines for Pregnant Women?

Have you heard?

There is a new bombshell from anti-vaccine folks!

It turns out, they say, that the FDA has admitted that the government is recommending untested, unlicensed vaccines for pregnant women.

Is that true?

Did the FDA Admit That the Government Is Recommending Untested, Unlicensed Vaccines for Pregnant Women?

Of course not!

Their evidence?

A response to a Freedom of Information Act request for vaccines that don’t exist. That’s right, neither Tdap nor flu vaccines are currently FDA approved for use by pregnant women.

Of course, that doesn’t mean that Tdap and flu vaccines aren’t recommended for use by pregnant women.

Wait, why the difference?

Why are pregnant women being given a vaccine that isn’t formally FDA approved for their use?

Well, vaccine manufacturers have to seek FDA approval for their products. The FDA doesn’t just up and approve new products or give them new indications. And none have ever sought approval in pregnancy.

But that doesn’t keep health experts from making off-label recommendations, such as getting a flu vaccine when you are pregnant.

“In prelicensure evaluations, the safety of administering a booster dose of Tdap to pregnant women was not studied. Because information on use of Tdap in pregnant women was lacking, both manufacturers of Tdap established pregnancy registries to collect information and pregnancy outcomes from pregnant women vaccinated with Tdap. Data on the safety of administering Tdap to pregnant women are now available.”

Updated Recommendations for Use of Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine (Tdap) in Pregnant Women and Persons Who Have or Anticipate Having Close Contact with an Infant Aged <12 Months — Advisory Committee on Immunization Practices (ACIP), 2011

As important as FDA approval is a recommendation from the Advisory Committee on Immunization Practices (ACIP). In fact, even after a vaccine gets approved by the FDA, it still has to get a recommendation from the ACIP before it gets on the immunization schedule and is used routinely!

“Flu shots have been given to millions of pregnant women over many years with a good safety record. There is a large body of scientific studies that supports the safety of flu vaccine in pregnant women and their babies.”

Flu Vaccine Safety and Pregnancy

Getting a flu vaccine during pregnancy is a recommendation that has been evolving since 1983. It was known to be safe then, and we are even more confident that it is safe now.

A Tdap shot has been recommended since 2011, although it was first suggested in 2008 that pregnancy was not a contraindication for receiving Tdap.

How do we know these vaccines are safe during pregnancy?

The Vaccine Safety Datalink has published more than 14 studies “related to pregnancy and vaccination during pregnancy” and has used “data to study the health of children born to women who were vaccinated during pregnancy.”

Despite what Robert F. Kennedy, Jr and his ironically named Children’s Health Defense organization might think, Tdap and flu shots in pregnancy have been well studied and have been found to be safe.

Ignoring all of the above studies, Kennedy highlights a few that he thinks found problems with flu shots in pregnancy, including one that showed “a suggestion of increased ASD risk among children whose mothers received an influenza vaccination in their first trimester,” a suggestion that was not statistically significant and which was not found in the other trimesters. And another that found an increased risk of spontaneous abortion in women who had also received a flu shot in the previous season, a safety signal that has never been seen before and which continues to be investigated.

Not surprisingly, his latest bombshell is landing with as big of a thud as his HHS lawsuit, as have most of his statements these days…

“CHD’s Chairman Robert F. Kennedy, Jr. notes that most flu shots given to pregnant women still contain a mercury-based preservative thimerosal.”

FDA Admits That Government Is Recommending Untested, Unlicensed Vaccines for Pregnant Women

Has Kennedy missed the fact that 80% of flu vaccines are now thimerosal free? It makes you wonder how he defines the word “most?”

“Thimerosal is acknowledged by Proposition 65 in California as a reproductive toxicant and exposure during pregnancy can cause learning and behavioral problems. Tdap contains aluminum, which FDA regulates as a toxin in parenteral nutrition but not in vaccines.”

FDA Admits That Government Is Recommending Untested, Unlicensed Vaccines for Pregnant Women

And what is he concerned about in thimerosal-free flu shots which also don’t contain aluminum? Are those okay in his book?

Mostly, after several flu seasons in which so many people have died, you have to wonder what his goal is here. Does Robert F. Kennedy, Jr. expect folks to skip getting a flu shot when they are pregnant and instead risk getting the flu? Should they skip their Tdap shot and risk their baby dying of whooping cough?

Or should they just stop listening to this type of anti-vaccine propaganda?

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