Tag: Yellow Card

Myths About the Yellow Fever Vaccine

Endemic yellow fever was eliminated in the United States in 1905, way before the first yellow fever vaccine was developed (1935) and licensed (1953).

How did that work?

Yellow fever is a now vaccine preventable disease that is spread by mosquito bites.

In the United States, it was actually eliminated by controlling the Aedes aegypti mosquitoes that spread the yellow fever virus before the vaccine was even developed. These control efforts were also done in Cuba, Panama, and Ecuador, etc., places where yellow fever was common and led to outbreaks in the United States.

Why Haven’t We Eradicated Yellow Fever?

So why is yellow fever still a problem if we can control the the Aedes aegypti mosquitoes that carry the yellow fever virus?

“Mosquitoes breed in tropical rainforests, humid, and semi-humid environments, as well as around bodies of still water in and close to human habitations in urban settings. Increased contact between humans and infected mosquitoes, particularly in urban areas where people have not been vaccinated for yellow fever, can create epidemics.”

Yellow fever: Questions and Answers

It’s because we can control the mosquitoes in urban areas, in and around cities. You can’t really control or eliminate mosquitoes in tropical rain forest regions, which is why it is difficult to eradicate yellow fever, malaria, dengue fever, and other mosquito borne diseases.

But we have a vaccine, don’t we?

“Eradication of yellow fever is not feasible since we are unable to control the virus in the natural animal hosts.”

Yellow fever: Questions and Answers

Unfortunately, we aren’t the only ones who can become infected with yellow fever. Monkeys get infected with the yellow fever virus in rain forests, infect Haemagogus and Sabethes mosquitoes, which bite people in those areas.

“Urban transmission of yellow fever virus occurs when the virus is spread from human to human by the Aedes aegypti mosquitoes.”

Yellow fever – Brazil

That likely means that yellow fever will never be completely eradicated, unlike small pox.

Yellow Fever Vaccines Myths

But just because yellow fever can’t be eradicated doesn’t mean that it can’t be eliminated.

A single dose of the yellow fever vaccine is safe and provides life-long protection for 99% of people.

“Vaccination is the most powerful known measure for yellow fever prevention: a single dose can provide life-long immunity at a cost of approximately US$1.”

WHO on Eliminating Yellow Fever Epidemics (EYE) Strategy: Meeting demand for yellow fever vaccines

And as cases of yellow fever increase in some countries, like Brazil, getting more people vaccinated is the only way to stop this deadly disease.

People line up to get a yellow fever vaccine near Kinshasa.
People line up to get a yellow fever vaccine near Kinshasa. Photo by WHO/E. Soteras Jalil

Tragically, anti-vaccination myths and misinformation may be keeping folks from getting vaccinated and protected. Propaganda and anti-vaccine scare videos have them thinking that the yellow fever vaccine is dangerous, part of a conspiracy to depopulate the world, or that it doesn’t work.

It is also important to know that:

  • When traveling to or from some countries, a yellow fever vaccine isn’t enough – you need an International Certificate of Vaccination proving that you were vaccinated.

    You should not skip getting the yellow fever vaccine if you are traveling to an area where yellow fever is endemic, including many parts of areas of Africa and South America.

  • While you are most at risk during the rainy season, especially during outbreaks, it is also possible to get yellow fever during the dry season.
  • Yellow fever is a serious, life-threatening disease.
  • There is no cure for yellow fever.
  • While serious side effects to the yellow fever vaccine have been reported, including anaphylaxis, yellow fever vaccine-associated neurologic disease (YEL-AND), and yellow fever vaccine-associated viscerotropic disease (YEL-AVD), they are very rare.
  • The yellow fever vaccine is a live virus vaccine, but shedding is not an issue. Unless at a high risk of exposure, getting the yellow fever vaccine is usually not recommended if you are pregnant or breastfeeding though.
  • It is not usually necessary to get a booster dose of the yellow fever vaccine.
  • Some countries require proof of yellow fever vaccination if you have traveled from a country where there is still a risk of getting yellow fever, so that you don’t import yellow fever into their country.

As yellow fever cases are on the rise in Brazil, with an associated increase in travel associated cases, it is important that everyone understand that vaccines are safe and necessary.

What to Know About Yellow Fever Vaccine Myths

Yellow fever cases are increasing and so are anti-vaccine myths about the yellow fever vaccine, which are keeping some folks from getting vaccinated and protected, even as they are threatened by a potential outbreak.

More on Yellow Fever Vaccines Myths

Can Vaccines Cause POTS?

Have you ever heard of POTS?

“In POTS, the lightheadedness or fainting is also accompanied by a rapid increase in heartbeat of more than 30 beats per minute, or a heart rate that exceeds 120 beats per minute, within 10 minutes of rising.”

NIH Postural Tachycardia Syndrome Information Page

POTS or postural orthostatic tachycardia syndrome was first identified in the early 1990s and can cause many debilitating symptoms, such as dizziness, headaches, and fatigue.

What Causes POTS?

We don’t know what causes POTS.

“The term “POTS” was coined in 1993 by a team of researchers from Mayo Clinic, led by neurologist Dr. Philip Low. However, POTS is not a new illness; it has been known by other names throughout history, such as DaCosta’s Syndrome, Soldier’s Heart, Mitral Valve Prolapse Syndrome, Neurocirculatory Asthenia, Chronic Orthostatic Intolerance, Orthostatic Tachycardia and Postural Tachycardia Syndrome.”

Dysautonomia International on POTS

Well, we know that POTS is caused by a malfunction of the patient’s autonomic nervous system (dysautonomia), but we don’t know always know what causes or triggers that malfunction.

Sometimes we do though, as POTS has been associated with other types of dysautonomia, like Ehlers-Danlos Syndrome and Mast Cell Disorders.

And genetics may play a role in some people with POTS.

Can Vaccines Cause POTS?

It shouldn’t be surprising that some folks think that vaccines could be associated with POTS.

“Anyone at any age can develop POTS, but the majority of individuals affected (between 75 and 80 percent) are women between the ages of 15 to 50 years of age.”

NIH Postural Tachycardia Syndrome Information Page

That’s right.

As more people were becoming aware of POTS, some of them were getting vaccinated for HPV.

But that correlation certainly doesn’t mean that vaccines cause POTS.

“POTS is a condition that causes lightheadedness or fainting and a rapid increase in heartbeat upon standing. The cause is unknown, but doctors think POTS may be associated with a number of risk factors and syndromes, including: a recent viral illness, physical deconditioning, chronic fatigue syndrome and nervous system problems.”

CDC on Can HPV vaccines cause POTS?

And studies have confirmed that, including:

  • In 2015, the European Medical Association confirmed evidence that HPV vaccines do not cause complex regional pain syndrome (CRPS) and postural orthostatic tachycardia syndrome (POTS)
  • A review of VAERS reports that “did not detect any unusual or unexpected reporting patterns that would suggest a safety problem” with HPV vaccination, including extra cases of POTS
  • A study in the UK using the MHRA’s Yellow Card passive surveillance scheme found no increase in reports of chronic fatigue syndromes following the introduction of Cervarix
  • A large, nationwide register-based study from Norway found no indication of increased risk of chronic fatigue syndrome/myalgic encephalomyelitis following HPV vaccination
  • A large cohort study of over 2 million young girls in France found no risk for autoimmune diseases (including neurological, rheumatological, hematological, endocrine, and gastro-intestinal disorders)
  • A large cohort study of girls in Sweden with pre-existing autoimmune diseases found that HPV vaccination was not associated with increased incidence of new-onset autoimmune disease (49 types of autoimmune diseases)

Contrast those large studies that are evidence against any association between vaccines and POTS with the case reports, anecdotal evidence, and vaccine scare stories that say there is.

“There is currently no conclusive evidence to support a causal relationship between the HPV vaccine and POTS. It is of utmost importance to recognize that although temporal associations may be observed, conclusions of causality cannot be drawn from case reports and case series due to the small sample size and lack of control population inherent to this type of scientific literature. If POTS does develop after receiving the HPV vaccine, it would appear to do so in a small subset of individuals and would be difficult to distinguish from the normal prevalence and incidence of the disorder.”

Butts et al on Human Papillomavirus Vaccine and Postural Orthostatic Tachycardia Syndrome: A Review of Current Literature

What about other vaccines? Could they cause POTS?

Folks should remember that a case report is basically a gloried anecdote and is not the kind of evidence you should use to make decisions about vaccinating and protecting your kids.
Folks should remember that a case report is basically a gloried anecdote and is not the kind of evidence you should use to make decisions about vaccinating and protecting your kids.

While the focus has been on the HPV vaccines, an issue with other vaccines causing POTS would have been picked up with our current vaccine safety systems.

But why has the focus been on the HPV vaccines?

It is an easy association to notice, after all POTS begins to occur right around when the HPV vaccines are given (teen years) and the HPV vaccines are given in many different countries. Most other vaccines that we give to teens in the United States, including Tdap and the meningococcal vaccines, aren’t as widely used in other countries.

But remember, POTS isn’t a new diagnosis. That anti-vaccine groups are latching onto it to scare parents away from vaccinating and protecting their kids is.

What to Know About Vaccines and POTS

There is no evidence that vaccines, especially the HPV vaccines, cause POTS.

More on Vaccines and POTS