Category: Vaccines

Does Pentacel Contain Mercury?

Thimerosal was taken out of most childhood vaccines in 2001, only remaining in muti-dose vials of flu vaccines, which could easily be avoided, as a good supply of thimersosal-free flu vaccine has been available for many years.

“Thimerosal is a mercury-based preservative that has been used for decades in the United States in multi-dose vials (vials containing more than one dose) of medicines and vaccines. There is no evidence of harm caused by the low doses of thimerosal in vaccines, except for minor reactions like redness and swelling at the injection site. However, in July 1999, the Public Health Service agencies, the American Academy of Pediatrics, and vaccine manufacturers agreed that thimerosal should be reduced or eliminated in vaccines as a precautionary measure.”

CDC on Thimerosal in Vaccines

For some reason, that hasn’t kept some parents from still being concerned about mercury in vaccines.

Does Pentacel Contain Mercury?

Pentacel is vaccine that combines the diphtheria and tetanus toxoids and acellular pertussis adsorbed, inactivated poliovirus and Haemophilus b conjugate (tetanus toxoid conjugate) vaccines (DTaP-IPV/Hib) into one shot.

Pentacel is mercury free.
Like most other vaccines on the childhood immunization schedule, Pentacel is mercury free.

It is routinely given to children as a four dose series, when they are 2, 4, 6, and 15 to 18 months old.

Like most other vaccines given to children, Pentacel is thimerosal-free.

It does not contain mercury.

More on Mercury in Vaccines

Can You Still Get Shingles After Having the Chicken Pox Vaccine?

It is very easy to get confused when thinking or talking about chicken pox and shingles.

Remembering a few things should help though:

  • shingles (herpes zoster) is a reactivation of chicken pox (varicella zoster) – since they are caused by the same virus, you had to have been exposed to the chicken pox virus (varicella zoster virus) to later get shingles
  • exposure to the chicken pox virus can come from a natural chicken pox infection or from getting vaccinated against chicken pox, as it is a live, attenuated vaccine (Varivax)

So no, getting the chicken pox vaccine will not prevent you from later getting shingles. The shingles vaccine is a different vaccine that is given to seniors to help prevent them from getting shingles.

Can You Still Get Shingles After Having the Chicken Pox Vaccine?

Have you ever heard of a child vaccinated against chicken pox getting shingles? It can happen. It’s not a vaccine injury.

Remember that you can get shingles at any age – it is not just a disease of senior citizens. Even preschools or teens can get shingles, with the risk increasing with age.

Although rare, even infants can develop shingles, most commonly if their mothers had a chicken pox infection while pregnant.
Although rare, even infants can develop shingles, most commonly if their mothers had a chicken pox infection while pregnant. Photo by Kaoutar Zinelabidine et al.

Although the chicken pox vaccine won’t prevent you from getting shingles, it does work well to prevent you from getting chicken pox.

And it is thought that getting vaccinated and protected against chicken pox will decrease your risk of later getting shingles, even before you ever get the shingles vaccine.

“In the early post-varicella vaccination period, incidence rates of medically attended herpes zoster did not increase for the overall population and decreased moderately for children 9 years and younger, the age group targeted for varicella vaccination.”

Tanuseputro et al on Population-based incidence of herpes zoster after introduction of a publicly funded varicella vaccination program

No chicken pox and a lower risk of shingles?

I’m glad my kids are fully vaccinated!

More on Shingles and the Chicken Pox Vaccine

Are You Ready for DNA Vaccines?

Believe it or not, vaccines aren’t a one-size-fits-all kind of a thing.

“There are several different types of vaccines. Each type is designed to teach your immune system how to fight off certain kinds of germs — and the serious diseases they cause.”

Vaccine Types

In addition to live vaccines, like MMR, there are inactivated vaccines, toxoid vaccines, and subunit, recombinant, polysaccharide, and conjugate vaccines.

Are You Ready for DNA Vaccines?

Vaccines made with current technology have helped save millions of lives.

It’s time for some new approaches though, especially as we are seeing the limitations of some of our current vaccines, especially the seasonal flu vaccine.

“DNA vaccines take immunization to a new technological level. These vaccines dispense with both the whole organism and its parts and get right down to the essentials: the microbe’s genetic material. In particular, DNA vaccines use the genes that code for those all-important antigens.”

NIH on Vaccine Types

While a DNA vaccine might sound like something out of the 23rd century, researchers have been studying them since the 1990s.

“Researchers have found that when the genes for a microbe’s antigens are introduced into the body, some cells will take up that DNA. The DNA then instructs those cells to make the antigen molecules. The cells secrete the antigens and display them on their surfaces. In other words, the body’s own cells become vaccine-making factories, creating the antigens necessary to stimulate the immune system.”

NIH on Vaccine Types

Does the idea of being injected with the genes for a microbe’s antigens scare you?

“The original concerns associated with the DNA platform were the potential for genomic integration and development of anti-DNA immune responses. Exhaustive research has found little evidence of integration, and the risk for integration appears to be significantly lower than that associated with naturally occurring mutations”

Ferraro et al on Clinical Applications of DNA Vaccines: Current Progress

What do you think happens when you get the flu?

The flu virus and it’s DNA is taken up by your cells, and those cells then start making more flu proteins.

“This approach offers a number of potential advantages over traditional approaches, including the stimulation of both B- and T-cell responses, improved vaccine stability, the absence of any infectious agent and the relative ease of large-scale manufacture.”

WHO on DNA Vaccines

So where are all of the DNA vaccines?

“However, the results of these early clinical trials were disappointing. The DNA vaccines were safe and well tolerated, but they proved to be poorly immunogenic. The induced antibody titers were very low or nonexistent, CD8+ T-cell responses were sporadic, and CD4+ T-cell responses were of low frequency. However, these studies provided proof of concept that DNA vaccines could safely induce immune responses (albeit low-level responses) in humans.”

Ferraro et al on Clinical Applications of DNA Vaccines: Current Progress

After getting disappointing results in the 1990s, researchers have since moved on to second-generation DNA vaccines, which are being tested for HIV treatment and prevention, Zika, Dengue fever, influenza (DNA vaccine prime), HPV, cancer treatment (metastatic breast, B cell lymphoma, melanoma, prostate, colorectal), chronic hepatitis B treatment, chronic hepatitis C treatment, herpes, and malaria.

There are many completed trials for DNA vaccines.
There are already many completed trials for DNA vaccines.

While many of these DNA vaccines are now in phase I and II trials, unfortunately, that means we are still a long time away from having a DNA vaccine on the immunization schedule.

More on DNA Vaccines

What Is a Hexavalent Vaccine?

Most folks know that we have combination vaccines that help reduce the number of injections that kids have to get at one visit.

You might not think of it as a combination vaccine, but one of the first, DPT, simply combines protection against diphtheria, pertussis, and tetanus into one shot.

Of course, we have come a long way since the days when DPT and MMR were considered combination vaccines.

Wait, why aren’t they considered combination vaccines anymore?

It’s not part of any conspiracy. It’s simply because you can’t get their individual components separately anymore. There is no measles or rubella shots anymore. Just the MMR. There is no tetanus shot.

Combination Vaccines

Not surprisingly, it is now becoming routine for kids to get combination vaccines instead of separate shots.

That’s because while the great majority of us want our kids vaccinated and protected, few enjoy shots and needles.

“The use of licensed combination vaccines is preferred over separate injection of their equivalent component vaccines.”

AAP on Combination Vaccines for Childhood Immunization

Does this mean more vaccines at one visit?

Nope.

“So, at a doctor’s visit, your child may only get two or three shots to protect him from five diseases, instead of five individual shots. Fewer shots may mean less pain for your child and less stress for you.”

CDC on Combination Vaccines

It just means fewer injections.

Combination vaccines combine the vaccines that you are already getting into one injection.

What Is a Hexavalent Vaccine?

And they might get even fewer with the latest hexavalent vaccines (six-in-one).

This is the next step up from our current pentavelent vaccines (five-in-one), like Pediarix (combines DTaP, Hep B, and IPV) and Pentacel (combines DTaP, IPV, and Hib).

The hexavalent vaccines combine protection against diphtheria, tetanus, acellular pertussis, Haemophilus influenzae type B, poliovirus and hepatitis B (DTaP-Hib-IPV-HepB) into one injection.

Sounds good, right?

Although not approved in the United States, hexavalent vaccines, including Infanrix Hexa have been used in many other countries since 2000! Another, Hexavac was withdrawn from the market because of issues with waning hepatitis B antibody titers (kids had levels that were still protective, but were on the low side).

When will get a hexavalent vaccine in the United States?

Obviously, the early problems with Hexavac kept us from getting a hexavalent vaccine, at least before the next generation of vaccines was developed.

Hexavalent vaccines are widely available in most parents of the world.
Hexavalent vaccines are widely available in most parents of the world.

Two new hexavalent vaccines, Vaxelis and Hexyon, have recently been licensed in Europe, after many studies showed that they worked and were safe when given with all of the other vaccines on the schedule, including Prevnar, rotavirus, Men C, and MMRV.

And one of these might soon be coming to the United States.

Vaxelis

V419 (Vaxelis), which was developed in collaboration between Merck and Sanofi Pasteur, has been under review by the FDA since 2014 has already received a Complete Response Letter that was “deemed complete and acceptable for review.”

And it was approved by the FDA on December 21, 2018.

Remember, that could mean just two shots at infant well check ups, but continued protection against eight vaccine-preventable diseases, as they get a hexavalent vaccine, Prevnar and the rotavirus vaccine!

It may be at least another year before Vaxelis makes it way to your pediatrician’s office though.

More on the Hexavalent Vaccine

Why Do You Need to Get a Flu Vaccine Each Year?

A yearly flu vaccine is the best way to protect yourself and your family against the flu.

But why do you need to get a flu vaccine each and every year?

Why Do You Need to Get a Flu Vaccine Each Year?

Hopefully we will one day have a universal flu vaccine that covers all flu strains and offers longer lasting protection.

Most folks know we don’t have that flu vaccine yet…

“A flu vaccine is needed every season for two reasons. First, the body’s immune response from vaccination declines over time, so an annual vaccine is needed for optimal protection. Second, because flu viruses are constantly changing, the formulation of the flu vaccine is reviewed each year and updated as needed to keep up with changing flu viruses. For the best protection, everyone 6 months and older should get vaccinated annually.”

CDC on Key Facts About Seasonal Flu Vaccine

So because the protection from the flu vaccine wanes or wears off relatively quickly, even if the flu vaccine strains don’t change from one year to the next, you should get a new flu vaccine.

How long does the protection from the flu vaccine last?

“An analysis from the 2011–12 through 2013–14 seasons noted protection ranging from 54% to 67% during days 0 through 180 postvaccination.”

Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices—United States, 2018–19 Influenza Season

The flu vaccines takes about two weeks to become effective and should then last for at least six months – long enough to get  you through the average flu season.

“A number of observational studies and a post hoc analysis from a randomized controlled trial have reported decreases in vaccine effectiveness (VE) within a single influenza season, with increasing time postvaccination. Waning effects have not been observed consistently across age groups, virus subtypes, and seasons; and observed declines in protection could be at least in part attributable to bias, unmeasured confounding, or the late season emergence of antigenic drift variants that are less well-matched to the vaccine strain. Some studies suggest this occurs to a greater degree with A(H3N2) viruses than with A(H1N1) or B viruses . This effect might also vary with recipient age; in some studies waning was more pronounced among older adults and younger children. Rates of decline in VE have also varied.”

Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices—United States, 2018–19 Influenza Season

That means it should last past the peak of the average flu season, which is typically between December and March.

And in most young, healthy people, the protection likely lasts even longer.

Make sure you are vaccinated well before flu season starts.
Make sure you are vaccinated well before flu season peaks, which since 1982 has occurred as early as October and as late as March, but is most common in February.

Still, there is some concern that the protection from the flu vaccine can wear off during a flu season, especially if you are very young, very old, or have chronic medical problems, and you get your flu vaccine early and you get exposed late – in April or May.

Of course, that’s not a good reason to delay getting a flu vaccine though, as waiting too long might leave you unprotected if flu peaks early, in October or November.

What to Know About Why You Need the Flu Vaccine Every Year

Since the flu vaccine strains can change and protection doesn’t last from season to season, get a flu vaccine each year. It’s the best way to protect yourself and your family against the flu.

More on Why You Need the Flu Vaccine Every Year

Why Are the DPT and OPV Vaccines Still Used in Some Countries?

As most folks know, neither the DPT nor OPV vaccines are used in the United States.

Pope Francis helped launch a polio vaccine campaign when he visited Mexico in 2016.
Pope Francis helped launch a polio vaccine campaign when he visited Mexico in 2016.

That they are still used in other countries likely raises some questions for those folks that get them.

Why Are the DPT and OPV Vaccines Still Used in Some Countries?

As I am sure you have guessed, there is no conspiracy about the continued use of these vaccines in other parts of the world. We aren’t getting rid of old stocks of vaccines or using cheaper vaccines in poorer parts of the world.

So what’s the reason?

To understand why they are still used in other countries, it helps to understand why they aren’t used here.

Remember that the DPT vaccine, which protects folks against diphtheria, pertussis, and tetanus, came under attack in the 1970s and 80s as some folks blamed the vaccine for causing vaccine injuries, including seizures and encephalopathy. It didn’t, but we still got a new vaccine, DTaP, which doesn’t seem to work as well.

“Although concerns about possible adverse events following their administration have led to the adoption of acellular pertussis vaccines in some countries, whole-cell pertussis vaccines are still widely produced and used globally in both developed and developing countries. Whole-cell pertussis vaccines that comply with WHO requirements, administered according to an optimal schedule have a long and successful record in the control of whooping cough. Furthermore, the excellent efficacy of some currently available whole-cell pertussis vaccine has also been shown, not only in recent clinical trials, but also on the basis of the resurgence of disease where vaccination has been interrupted or when coverage has markedly decreased. Therefore, WHO continues to recommend whole-cell pertussis vaccines for use in national immunization programmes.”

WHO on Recommendations for whole-cell pertussis vaccine

The WHO now recommends that if countries do switch to DTaP,  the acellular pertussis vaccine, they should be prepared to add additional periodic booster doses and immunizations during pregnancy, which may still “may not be sufficient to prevent resurgence of pertussis.”

The OPV vaccine, on the other hand, was replaced because it can rarely cause vaccine-associated paralytic polio (VAPP) and circulating vaccine-derived polio virus (cVDPV). Of course, it does it at much lower rates than wild polio virus, so until polio is well controlled, the benefit of using OPV outweighs the risk. In addition to being less expensive and easier to use, OPV has the benefit over IPV of providing better herd immunity.

At some point, as we did in the United States in 2000, countries make a switch to the IPV vaccine.

In 2016, remaining countries that use OPV switched from trivalent OPV to bivalent OPV, because wild polio virus type 2 was eradicated in 1999. Once the remaining two types are eradicated, we can stop using the OPV vaccine altogether.

Until then, countries either use:

  • OPV plus one dose of IPV
  • sequential IPV-OPV schedules – high vaccine coverage and low risk of wild polio importation
  • IPV only schedules – sustained high vaccine coverage and very low risk of wild polio importation

So there is no conspiracy. These vaccines are safe and they work.

Without them, there would be over:

  • 1.3 million pertussis related deaths each year
  • 600,000 cases of paralytic polio each year

With most of these cases affecting young children.

More on the Continued Use of DPT and OPV Vaccines

Why Isn’t There a Vaccine for Leprosy?

Why do anti-vaccine folks talk about leprosy (Hansen’s disease) so much?

“LEPROSY. I’m curious why there isn’t a vaccine for leprosy. With all the other bazillion vaccines out there, why not one for leprosy?”

We don’t have anywhere near a bazillion vaccines, but did you know that there actually is a vaccine for leprosy?

“Why aren’t you walking around concerned about leprosy every day? Why aren’t you concerned about someone from another country bringing leprosy into Australia or the US and somehow exposing all of our most vulnerable to this illness? I’ll tell you why. Because there’s no vaccine for leprosy. You are afraid of what we vaccinate for because these illnesses are hyped up all of the time. It’s propaganda. ”

Learn the Risk – Why aren’t we afraid of all diseases?

Don’t expect the leprosy vaccine to be added to our immunization schedule any time soon or to increase your fears about leprosy, as leprosy is not highly contagious and it can be treated, and even cured.

And while there are about 150 to 250 cases in the United States each year, most are in folks who used to live in areas of the world where leprosy is more common. Unlike measles, you aren’t likely to get leprosy at school or daycare or going to Disneyland, although you could get it if you have a pet armadillo.

Leprosy Vaccines

A vaccine against leprosy is important though. As with other diseases, we are seeing multi-drug resistant forms of Mycobacterium leprae, the bacteria that causes leprosy.

The new leprosy vaccine that is being developed will hopefully help to finally eliminate leprosy in parts of the Africa, Asia and Latin America where it is still a problem.

Throughout much of the 20th Century, people with leprosy in the United States were treated at the National Leprosarium in Carville, Louisiana.
Throughout much of the 20th Century, people with leprosy in the United States were treated at the National Leprosarium in Carville, Louisiana.

But it isn’t the first leprosy vaccine that we will have had.

Various leprosy vaccines have been developed and tested since the 1980s.

Also, the M. bovis BCG vaccine has been known to provide protection against both Mycobacterium tuberculosis (tuberculosis) and the related Mycobacterium leprae (leprosy) since as early as 1939.

“BCG vaccination is recommended in countries or settings with a high incidence of TB and/or high leprosy burden.”

BCG vaccines: WHO position paper – February 2018

The new leprosy vaccine, a sub-unit vaccine, will hopefully be more effective than previous strategies though, and will work to both prevent and treat leprosy.

Another leprosy vaccine, Mycobacterium indicus pranii (MIP), is being developed and tested in India.

Still, leprosy will never be eradicated, as armadillos serve as an animal reservoir for the Mycobacterium leprae  bacteria.

What to Know About Leprosy Vaccines

At least two leprosy vaccines are being developed and tested to help eliminate leprosy from the areas of Africa, Asia and Latin America where it is still a problem.

More on Leprosy Vaccines