Tag: natural immunity

Dengvaxia for Dengue Fever

Dengvaxia was recently approved by the FDA after being available in other countries since about 2015.

“Indicated for the prevention of dengue disease caused by dengue virus serotypes 1, 2, 3 and 4. DENGVAXIA is approved for use in individuals 9 through 16 years of age with laboratory-confirmed previous dengue infection and living in endemic areas.”

Wait.

Dengue is endemic throughout the tropics and subtropics, including most of the Caribbean.
Dengue is endemic throughout the tropics and subtropics, including most of the Caribbean.

It’s only for people who have already had a dengue infection before?

Dengvaxia Controversy

Unfortunately, Dengvaxia “performs differently in seropositive versus seronegative individuals.”

“In areas of 70% dengue seroprevalence, over a 5-year follow-up, for every 4 severe cases prevented in seropositive, there would be one excess severe case in seronegative per 1,000 vaccinees; for every 13 hospitalizations prevented in seropositive vaccinees, there would be 1 excess hospitalization in seronegative vaccinees per 1,000 vaccinees.”

WHO on Questions and Answers on Dengue Vaccines

If you have never had dengue before and you are vaccinated, you are at risk for a severe infection if you do get dengue. On the other hand, if you are unvaccinated, you are at even greater risk of getting dengue, a life-threatening infection. Fortunately, the first episode of dengue is usually fairly mild.

The problem occurs if your antibody levels have dropped enough, which can cause you to have a severe case of dengue the second time. The process is called antibody-dependent enhancement and has to do with antibody levels, either natural or vaccine induced. So it can occur whether or not you are vaccinated, although getting Dengvaxia, an attenuated, live vaccine, can act as a primary dengue infection.

“These differing epidemiological features support the conclusion that antibody dependent enhanced (ADE) dengue disease occurred in seronegatives who were sensitized by vaccine. As hospitalizations continue to occur in all age groups Dengvaxia consumers should be warned that sensitized vaccinated seronegatives will experience enhanced dengue disease into the forseeable future.”

Scott Halstead on Dengvaxia sensitizes seronegatives to vaccine enhanced disease regardless of age.

It is something that dengue researcher Scott Halstead warned folks about as soon as he saw the first published study on Dengvaxia.

But why would you need a vaccine if you have already had dengue?

“In humans recovery from infection by one dengue virus provides lifelong immunity against that particular virus serotype. However, this immunity confers only partial and transient protection against subsequent infection by the other three serotypes of the virus. Evidence points to the fact that sequential infection increases the risk of developing severe dengue.”

WHO on Dengue control

There are four serotypes of dengue.

So if you aren’t vaccinated, you are at risk to get dengue multiple times.

Tragically, about 800,000 children in the Philippines were given Dengvaxia in a universal immunization program without checking to see if they had dengue first. And it likely led to some severe cases of dengue and deaths. This led to the vaccine being banned in that country and is thought to be one of the causes behind their current measles outbreak, as their Dengvaxia controversy led to more vaccine hesitancy.

And it will lead to more folks getting dengue. Instead of a ban, they should likely be more picky about who they give the vaccine to, either confirming that recipients have already had dengue (titer test) or only giving the vaccine to older kids.

Dengvaxia for Dengue Fever

Do you need Dengvaxia?

Remember, Dengvaxia is only for those living in endemic areas and in the United States, dengue is only endemic in the U.S. territories of American Samoa, Guam, Puerto Rico, and the U.S. Virgin Islands.

Do you need Dengvaxia if you are simply traveling to one of these areas?

Since Dengvaxia is not approved for those who haven’t had a dengue infection before, you likely wouldn’t get it just for traveling to an endemic area, unless perhaps you routinely travel to an endemic area and have had dengue already. A titer test can confirm a previous dengue infection, but there is no indication to get vaccinated for travel yet.

Also, while in other countries it is available for use between 9 and 45 years, in the United States, Dengvaxia is only approved for children between 9 and 16 years of age.

More on Dengvaxia for Dengue Fever

Should I Stop Calling Chickenpox and Measles Diseases?

Sherri Tenpenny wants us to stop calling chickenpox and measles diseases.

She thinks that we should call them infections instead…

Should I Stop Calling Chickenpox and Measles Diseases?

If you are like most people, you are probably thinking to yourself and maybe even shouting at your computer screen right now, “who cares what you call them, just get vaccinated and stop the outbreaks!”

When you vaccinate to avoid an infection, what you are potentially doing is preventing a death!
When you vaccinate to avoid an infection, what you are potentially doing is preventing a death!

Believe it or not, there is actually some precedent for changing the way we talk about diseases. While you may still refer to them as STDs, or sexually transmitted diseases out of habit, the prefererable term is actually STI, or sexually tranmistted infection.

Of course, this has nothing to do with Tenpenny’s reasoning.

“Why the change? The concept of ‘disease,’ as in STD, suggests a clear medical problem, usually some obvious signs or symptoms. But several of the most common STDs have no signs or symptoms in the majority of persons infected. Or they have mild signs and symptoms that can be easily overlooked. So the sexually transmitted virus or bacteria can be described as creating ‘infection,’ which may or may not result in ‘disease.’ This is true of chlamydia, gonorrhea, herpes, and human papillomavirus (HPV), to name a few.

For this reason, for some professionals and organizations the term ‘disease’ is being replaced by ‘infection.'”

ASHA on STDs/STIs

In fact, their definitions sound nothing like Tenpennys…

Unfortunately, many STIs, even if they aren’t causing symptoms and disease, can still be contagious.

Measles and chickenpox don’t do that. Although you can be contagious just before you start to have symptoms, you will very quickly develop symptoms.

It is true that some viruses and bacteria can lead to subclinical infections, in which you develop immunity without ever developing symptoms, but that doesn’t usually happen with measles and chicken pox.

Polio is one of the best examples of when it does happen. Remember, nearly 75% of kids who got polio never had any symptoms. Tragically, those symptoms could be severe in the small percentage who did.

So as usual, Sherri Tenpenny is wrong.

Chickenpox and measles are infections that cause disease. And while most people recover after 7 to 10 days of symptoms, including a high fever and rash, some don’t.

Both also put you at risk for long-term complications, namely shingles and SSPE.

Remember, if you listen to folks like her and skip or delay your child’s vaccines and they get chickenpox or measles, the only thing you are doing is causing more people to get sick. A catchy slogan won’t prevent that or keep your kids healthy.

More on Diseases vs Infections

Can Vaccines Cause Rhabdomyolysis?

The urine is dark because of myoglobinuria secondary to muscle break down. Hemoglobinuria, from blood, is the other thing that makes urine dark.
The urine is dark because of myoglobinuria secondary to muscle break down. Hemoglobinuria, from blood, is the other thing that makes urine dark. Photo Kumar et al (CC BY-NC-SA 3.0 US).

You have probably never heard of rhabdomyolysis.

Children with rhabdomyolysis have severe muscle pain, muscle weakness, and dark urine.

It is classically caused by exercising too much (really overdoing it or exercising a lot more or a lot longer than you typically do) and damaging your muscles, leading to a breakdown of muscle cells and the release of creatine kinase, which in addition to muscle symptoms, can lead to kidney failure.

In addition to exercise, rhabdomyolysis can be caused by seizures, drugs, toxins, insect stings, snake bites, metabolic disorders, infections (viral myositis), and trauma.

“The most common causes of pediatric rhabdomyolysis were viral myositis (38%), trauma (26%), and connective tissue disease (5%).”

Mannix et al on Acute Pediatric Rhabdomyolysis: Causes and Rates of Renal Failure

Keep in mind that rhabdomyolysis is rare. You won’t confuse the aches and pains that most kids get, and which often get blamed on growing pains, with rhabdomyolysis. Although younger kids don’t always have dark urine when they have rhabdo, the pain and weakness is severe. Seek immediate medical attention if you think that your child might have rhabdomyolysis.

Can Vaccines Cause Rhabdomyolysis?

It is well known that rhabdomyolysis can be caused by infections.

“Rhabdomyolysis has been reported to be associated with a variety of viral infections, including influenza, [15,16] Coxsackie virus, human immunodeficiency virus (HIV), echovirus and cytomegalovirus [17]. In our series, the definite viral infection was identified in 5 patients (influenza type B in 4, Coxsackie A10 in 1)”

Chen et al on Clinical spectrum of rhabdomyolysis presented to pediatric emergency department

So if a natural influenza virus infection can cause rhabdomyolysis, does that mean that the flu vaccine can too? What about other vaccines?

Not necessarily, but there are a few case reports that associate vaccines with rhabdomyolysis.

“Influenza A infection has been described as a major viral cause of infection-induced rhabdomyolysis, but to date, only one reported case was described as having been induced by influenza vaccine.”

Callado et al on Rhabdomyolysis secondary to influenza A H1N1 vaccine resulting in acute kidney injury.

In several of the reports, patients already had chronic medical problems for which they were being treated. Still, no signal was found to suggest that the flu vaccine is a problem for these patients.

It is important to note that reports of post-vaccination rhabdomyolysis in healthy people are even rarer.

So while it is could be possible that vaccines are rarely associated with rhabdomyolysis, we know that many infections, including many vaccine-preventable diseases, are a more common cause.

Don’t skip or delay a vaccine because you might have heard that vaccines cause rhabdomyolysis.

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

More on Vaccines and Rhabdomyolysis

Who Gets SSPE?

Have you heard that you can get SSPE from the MMR?

Apparently it’s in the vaccine insert…

Who Gets SSPE?

Subacute sclerosing panencephalitis (SSPE) occurs after a natural measles infection.

You won't get SSPE if you don't get measles.

It is not caused by MMR or any measles containing vaccine.

Of course, the measles vaccine is not 100% effective, so it is possible that you could still get measles after being vaccinated. And those folks who get measles after getting vaccinated could be at risk to get SSPE, but even then, their SSPE would be caused by wild measles virus, not a vaccine strain.

“Available epidemiological data are consistent with a directly protective effect of vaccine against SSPE mediated by preventing measles.”

Subacute sclerosing panencephalitis and measles vaccination

Again, SSPE is caused by natural measles infections and the wild type measles virus.

Tragically, after big outbreaks of measles, we start to see more cases of SSPE, with the greatest in children who get measles at a young age.

And SSPE is universally fatal in these children, who develop symptoms about six to eight years after recovering from having measles.

That the symptoms of SSPE don’t develop until long after you have recovered from measles is why the condition is often described as a time-bomb.

A time-bomb that you can’t stop.

Want to avoid getting SSPE? Get vaccinated and protected against measles.

More on Getting SSPE

Do You Need Another Dose of the MMR Vaccine?

The measles outbreaks have a lot of people concerned about measles.

And that means measles and vaccines are getting a lot of extra attention.

Unfortunately, getting extra attention doesn’t always translate into getting great advice, especially when it is leading a lot of folks into thinking they need to rush out and get another dose of MMR or to check their titers to make sure they are protected.

Do You Need Another Dose of the MMR Vaccine?

So are you protected against measles?

Have you had two doses of MMR? (Remember, kids typically get their first dose at age 12-15 months and a second dose when they are 4-6 years old, with early doses in high-risk situations.)

If you have documentation of two doses of MMR (or a measles containing vaccine), then you can confidently say that you are protected. No, it’s not 100% protection, but it’s close.

“Documented age-appropriate vaccination supersedes the results of subsequent serologic testing. If a person who has 2 documented doses of measles- or mumps-containing vaccines is tested serologically and is determined to have negative or equivocal measles or mumps titer results, it is not recommended that the person receive an additional dose of MMR vaccine. Such persons should be considered to have presumptive evidence of immunity.”

Prevention of Measles, Rubella, Congenital Rubella Syndrome, and Mumps, 2013: Summary Recommendations of the Advisory Committee on Immunization Practices (ACIP)

If you haven’t had two doses of MMR, then know that two doses are your best protection against measles.

Have you heard that people born before 1989 may need another dose?

What is the significance of the year 1989?

The recommendation to give a routine second dose of MMR started in 1990, so folks born much before then likely only had one dose, unless they were considered high risk and had the second dose before traveling out of the country, starting a healthcare job, or going to college, etc.

Instead of 1989, the typical cutoff year for protection is around 1986, since those kids would have been turning four years old in 1990, so would have gotten their second dose of MMR on schedule. If you were born before 1986, you would have started kindergarten before the recommendation to get a second dose.

The other years that are important are 1963 to 1967, as that’s when the very first measles vaccine was used, a vaccine that was later found to not be very effective. If that is the only time you were vaccinated, then you should be vaccinated again.

What about 1957?

In general, if you were born before 1957, we assume that you had measles because most people had measles back then. Maybe you didn’t though, so in a high-risk situation, like traveling out of the country or in the middle of an outbreak, this could be a good situation to check your measles titer to confirm that you are immune. If you aren’t, then get two doses of MMR.

How many doses of MMR have you had?
How many doses of MMR have you had?

So here are your scenarios:

  • Were you born before 1957? Then you probably had measles, but can check your titers to make sure you are immune, especially if you will be in a high-risk situation, like near an outbreak or traveling.
  • Did you get a dose of measles vaccine between 1963 and 1967? If this was your only dose, then you should get a dose of MMR now.
  • Did you get a measles vaccine between 1968 and 1971, before the MMR became available? That counts as a dose of measles containing vaccine. If that is your only dose, then you might get another dose of MMR, if you will be in a high-risk situation, like near an outbreak or traveling.
  • Have you only had only one dose of MMR or other measles containing vaccine, which is more likely if you were born well before 1990? Then get another dose of MMR if you will be in a high-risk situation, like near an outbreak or traveling.
  • Have you had two doses of MMR vaccine or or other measles containing vaccine (and have your immunization records to prove it)? Then you should be protected. You don’t need to check your titers and you don’t need a third dose of MMR.

What if you aren’t sure? Then get at least one more dose of MMR.

If you don’t think that you were ever vaccinated against measles, then you might get two doses of MMR.

If you aren’t sure, but think that you already were vaccinated, then this would be a good situation to check your titer. Be prepared to get your MMR vaccines again if you are negative though.

Do all adults need two doses of MMR?

Surprisingly no, although that is considered the best protection against measles, there was never a general catch up program for older folks with the recommendation to get a second dose in 1990. So if you have had one dose of MMR and aren’t at any extra risk to get measles – no travel, no nearby outbreaks, and not a health professional, etc., then one dose might be enough… for now.

More on MMR Vaccines

What’s the Evidence for Measles Parties?

We know that folks are still having chicken pox parties.

How do we know.

Are they using MeetUp to have chicken pox parties?
Are they using MeetUp to have chicken pox parties?

For one thing, the Governor of Kentucky recently came out as having said he took his kids to one…

What’s the Evidence for Measles Parties?

But measles parties?

That can’t still be a thing, can it?

Until recently, I would have said, “no way!”

I mean, realistically, in most years, there were so few cases that it would have made it hard to find someone to intentionally expose your kid to.

That’s changed recently though.

“In Facebook group discussions, local activists have asked about holding “measles parties” to expose unvaccinated children to others infected with the virus so they can contract the disease and acquire immunity.”

Despite measles outbreak, anti-vaccine activists in Minnesota refuse to back down

As outbreaks get bigger, especially since they are typically concentrated among clusters of unvaccinated children and adults in small communities, the possibility of measles parties become more possible.

They might even be likely when you have anti-vaccine folks encouraging folks to have them!

A case of measles was reported in Indianapolis on March 27…

What about evidence of measles parties in Brooklyn?

Hopefully the The Chanukah Measles Song is someone’s idea of a really sick joke…

The health department, in their press conference, does mention reports of measles parties. And that they think some people may be using the exposures so that their intentionally sick kids will later test positive when titer tests are done.

I hope they aren’t, but who knows…

Literally hoping for a life-threatening disease for your kids? Really?

Unfortunately, there are plenty of people claiming that they would like to intentionally expose their kids to measles. Hopefully they are just folks trying to get attention and wouldn’t really do that to their kids.

Vaccines are safe, with few risks, and necessary. There is no good reason to intentionally expose your kids to a potentially life-threatening disease.

More on Measles Parties

Why Do We Include SSPE When Counting Measles Deaths?

Anti-vaccine folks often like to push the idea that parents shouldn’t worry about measles and that it is just a rash with a little fever.

They leave out the part that it is a week of having a high fever, irritability, and other symptoms too.

In addition to downplaying the symptoms of measles, they never talk about the possible complications, such as encephalitis, seizures, and death.

Why Do We Include SSPE When Counting Measles Deaths?

They certainly never talk about SSPE or subacute sclerosing panencephalitis.

“Subacute sclerosing panencephalitis (SSPE) is a progressive neurological disorder of children and young adults that affects the central nervous system (CNS). It is a slow, but persistent, viral infection caused by defective measles virus.”

Subacute Sclerosing Panencephalitis Information Page

SSPE is a late complication of having a natural measles infection.

That’s why it should be included when counting measles deaths.

“Available epidemiological data, in line with virus genotyping data, do not suggest that measles vaccine virus can cause SSPE. Furthermore, epidemiological data do not suggest that the administration of measles vaccine can accelerate the course of SSPE or trigger SSPE in an individual who would have developed the disease at a later time without immunization. Neither can the vaccine lead to the development of SSPE where it would not otherwise have occurred in a person who has already a benign persistent wild measles infection at the time of vaccination.”

Subacute sclerosing panencephalitis and measles vaccination

It is not a complication of having a measles containing vaccine. If it were, then why didn’t we see more cases of SSPE as more and more people got vaccinated, instead of a drop in SSPE cases and deaths, corresponding to a drop in measles cases?

But SSPE isn’t gone yet, just like measles hasn’t yet been eradicated.

32 of these SSPE deaths have been since 2000. Source is the CDC Wonder database.
32 of these SSPE deaths have been since 2000. Source is the CDC Wonder database.

Since 2000, when the endemic spread of measles was eliminated in the United States, there have been at least 37 SSPE deaths.

“Investigators learned that, in 2012, at age 11 years, the boy, who was previously healthy and developmentally normal, had been admitted to a tertiary care children’s hospital in Oregon with severe, progressive encephalopathy. Before the onset of his neurologic illness, the patient had been a straight-A, fifth-grade student who played soccer and basketball. The symptoms began approximately 4 months before the hospital admission, when the patient began to struggle with homework, drop utensils, and doze off during meals, eventually progressing to falling asleep while walking.”

Notes from the Field: Subacute Sclerosing Panencephalitis Death — Oregon, 2015

I say at least, because the CDC Wonder database doesn’t list the 2015 SSPE death of a boy in Oregon.

Anti-vaccine folks like to ignore the fact that yes, people have died of measles recently. And measles puts you at risk for SSPE, which is always fatal.
Anti-vaccine folks like to ignore the fact that yes, people have died of measles recently. And measles puts you at risk for SSPE, which is always fatal.

We are fortunate that no one has died since 2015, but as we get more and more measles cases, tragically, in addition of the risk of someone dying of measles directly, it increases the risk that someone will eventually develop SSPE.

“Decreasing rates of vaccination in the United States, particularly among preschool-aged children (children <5 years of age) living in inner-city areas, resulted in a resurgence in the number of cases of measles reported during 1989–1991; during this period, 55,622 cases of measles and 123 measles-associated deaths were reported.”

Bellini et al on Subacute Sclerosing Panencephalitis: More Cases of This Fatal Disease Are Prevented by Measles Immunization than Was Previously Recognized

Remember, there were at least 12 extra SSPE deaths following the large measles outbreaks of the late 1980s.

Will we see any after the rise in the cases the last few years?

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

Don’t risk a complication of measles. Don’t risk getting SSPE.

More on SSPE Deaths