Tag: Tdap

Why is the Tdap Vaccine in Category C?

The Tdap vaccine is routinely recommended for all pregnant women, so why would it be in the FDA Category C?

The FDA has actually removed the pregnancy categories.

We should start by stating that “risk-benefit decisions regarding use of a drug during pregnancy are more complex than the category designations suggest.”

Why is the Tdap Vaccine in Category C?

Anyway, the category designations are no longer being used on new drugs and vaccines.

“In December of 2014, the FDA published the Content and Format of Labeling for Human Prescription Drug and Biological Products; Requirements for Pregnancy and Lactation Labeling, referred to as the “Pregnancy and Lactation Labeling Rule” (PLLR or final rule). The PLLR removes pregnancy letter categories – A, B, C, D and X. Instead, under the final rule, narrative summaries of the risks of a drug during pregnancy and discussions of the data supporting those summaries are required in labeling to provide more meaningful information for clinicians.”

Guidelines for Vaccinating Pregnant Women

So is it still Category C?

Yes, for now. Few vaccines have converted to the new labeling system yet, which still leaves us with:

  • Pregnancy Category B: Tdap (Boostrix) – Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women OR Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus during the first trimester (and there is no evidence of risk in later trimesters).
  • Pregnancy Category C: Tdap (Adacel) – Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks OR Animal reproduction studies have not been conducted and there are no adequate and well-controlled studies in humans.

Of course, 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.”

And many of these studies are about the Tdap vaccine!

“There are no theoretical or proven concerns about the safety of the Tdap vaccine (or other inactivated vaccines like Tdap) during pregnancy. The shot is safe when given to pregnant women.”

Frequently Asked Questions for Pregnant Women Concerning Tdap Vaccination

This will likely be reflected when we get new labels for these vaccines, with wording that makes it clear that Tdap vaccines are safe in pregnancy.

what to know about the tdap vaccines and their category c designation

Tdap vaccines still have a Category C designation simply because their labels haven’t been updated to reflect the latest safety studies.

More on Tdap Vaccines and Category C

What Percentage of Adults Are up to Date on Their Immunizations?

Are you up to date on your vaccines?

What about everyone else?

What Percentage of Adults Are up to Date on Their Immunizations?

Can you guess why this question comes up so often?

Yup.

There is no plan to force adults to get vaccinated...
There is no plan to force adults to get vaccinated…

It’s about herd immunity.

If most adults aren’t immune because they haven’t been vaccinated or don’t get boosters, then since we aren’t seeing that many outbreaks, herd immunity itself must be a myth.

The thing is though, adults were either born in the pre-vaccine era and likely earned their natural immunity or were born in the vaccine era and are vaccinated and immune.

It is also important to understand that herd immunity is disease specific, so when we talk about herd immunity for measles, it doesn’t matter if everyone has herd immunity levels of protection against hepatitis A or Hib.

And adults do get a few boosters and some vaccines that are only recommended for adults, including the shingles vaccine.

In addition, some vaccines, like Hib and Prevnar, have indirect effects, protecting adults even though they aren’t vaccinated, because vaccinated kids are less likely to become infectious.

But back to the original question, how many adults are up to date on their immunizations?

“While modest gains occurred in vaccination coverage for pneumococcal, Tdap, hepatitis A (persons with chronic liver conditions), herpes zoster, and HPV vaccination, coverage did not improve for other vaccinations and many adults remained unvaccinated with recommended vaccines. “

Vaccination Coverage Among Adults in the United States, National Health Interview Survey, 2016

While most adults are immune to what were once common childhood diseases, like measles and mumps, because they were either vaccinated or had the disease naturally, many could do better with newer vaccines that weren’t available when they were kids.

More on Adult Vaccination Statistics

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

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.

More on the Last Case of Diphtheria