There are a lot of nuanced facts and evidence about vaccines. The so-called “pro-vaccine” crowd looks at the body of evidence, then concludes that it saves children’s lives by stopping vaccine-preventable diseases. The “anti-vaccine” side seems to rely on anecdotes, cherry picking bad studies published in really bad journals, and read anti-science websites, just to support their preconceived conclusions. And now there is a lot of junk science with respect to chickenpox and shingles, much of which we need to refute and debunk.
One of the enduring myths of the antivaccine cult is that chickenpox vaccine will increase the rate of shingles, especially in older adults. A published article examines chickenpox and shingles vaccines – and like everything in science, it’s the nuanced data that makes the story. Not the headlines.
What is chickenpox? Shingles?
One of the consequences of contracting chickenpox, a virus called Varicella zoster, is that the virus is not destroyed by the body’s immune system. Once the symptoms of chickenpox disappear, the virus hides (it does not do this consciously, it’s a virus) in the dorsal root ganglion, a bundle of nerve fibers at the bottom of the spinal column. The virus just hangs out there, basically hidden from the body’s immune system.
We are not sure why it does this, but it may be an evolutionary adaptation to survive until a later point in time so that it can reproduce and reinfect the victim. Of course, viruses are very simple organisms (and some biologists will debate that it’s not a living organism), so complex behavior may be pushing our understanding of a virus.
Even though the body generated an immune response to the original zoster virus infection, several years or decades after the initial infection, the adaptive immune response wanes, weakens or disappears. Due to other unknown factors, possibly stress or other infections, the zoster virus “moves” (again, it’s a virus, so it just multiplies without purpose) along the nerve bundles, and causes the second infection with much more serious consequences to the patient.
This second infection is called herpes zoster (see Note 1), and more commonly known as shingles. This infection usually happens when the patient is older than 50, although it can happen at any time, occasionally even in young adults.
What can be said about shingles is that it’s an entirely unpredictable disease. It really appears at random points in time in response to unknown variables. Once shingles appear, it is incredibly painful, depending on the location of the outbreak. It can cause a blindness, disfigurement of the area infected, permanent pain, and other conditions.
Shingles can be treated with antiviral drugs, but only if the infection is recognized and treated within 24-72 hours, a time frame that might not allow most individuals to get to their doctor. The initial symptoms may even appear like acne or some other skin condition, which many people might ignore. After 72 hours, the disease has to run its painful and dangerous course. The pain of shingles may last for weeks, months, or even years after the blisters have healed – this is not a trivial disease.
The only way to prevent a shingles infection is to boost the immune system with a new vaccine against the zoster virus. Zostavax (a shingles vaccine available in the USA) has been approved by the FDA for prevention of shingles in 50-59-year-olds (and it has previously been approved for 60-69-year-olds). If I had contracted chickenpox, I’d ask for the vaccine even in my 40’s, just to prevent the more serious shingles outbreak. But that’s not medical advice.
So let’s be clear about a couple of things. First, you are only at risk for shingles if you contracted chickenpox. Second, children who have been vaccinated against chickenpox probably will never, ever contract shingles. Is this clear? Chickenpox vaccine prevents chickenpox AND shingles.
Why worry about this? Chickenpox isn’t dangerous
Wrong. there are real complications from a varicella infection, which are numerous and serious:
- bleeding problems
- infection or inflammation of the brain (encephalitis, cerebellar ataxia)
- bacterial infections of the skin and soft tissues in children including Group A streptococcal infections
- bloodstream infections (sepsis)
- toxic shock syndrome
- bone infections
- joint infections
And just in case one of you might wonder, here’s what the CDC says about chickenpox:
Some people with serious complications from chickenpox can become so sick that they need to be hospitalized. Chickenpox can also cause death.
Some deaths from chickenpox continue to occur in healthy, unvaccinated children and adults. Many of the healthy adults who died from chickenpox contracted the disease from their unvaccinated children.
Yes, healthy children can die from chickenpox. Let that sink in. Chickenpox and shingles are both dangerous, deadly diseases. Let that also sink in.
Chickenpox and shingles – the vaccine facts
One of the enduring myths of the antivaccination movement is that the reservoir of chickenpox in children “immunize” adults against shingles. So these people claim that vaccinating against the “minor” disease of chickenpox harms adults later in life.
There might be some biological plausibility to that claim, but there are at least three major ethical issues:
- Using children as a vehicle to immunize adults has got to be one of the most morally repugnant beliefs of the anti-vaccine crowd. Seriously, these anti-vaccine religion adherents feign their concern about children, yet to protect adults they are willing to let their children get a serious disease.
- Since chickenpox is not a minor disease, refusing the varicella vaccine puts the child at harm.
- Immune-compromised children and adults are at serious risk of great harm if exposed to chickenpox (it’s truly a nasty virus). We should be interested in protecting those people too.
Ignoring the moral implications, let’s look at the recent research.
In the study published in the journal eLife, scientists from the Universities of Antwerp and Hasselt (Belgium) have predicted that the temporary effect of a rise in shingles cases, after vaccinating one-year-old children against chickenpox, dominates in 31 to 40-year-olds.
This article found that a chickenpox vaccination strategy for children could temporarily (see, a nuanced word) double the incidence of shingles in a broad population. However, it is in younger adults rather than older ones, where shingles is much more prevalent.
Many countries have avoided introducing universal chickenpox vaccination in children because it was believed, even by experts in public health, that the reduction in chickenpox-related disease would be counter-balanced by a temporary increase in shingles. This study actually debunks that belief.
Previously, scientists thought that the potential immune effect against shingles by recurrent chickenpox infections in children would last around 20 years. Based on real immunological and virological data from individuals, a new model of chickenpox vaccine and shingles, developed by the scientists in Belgium, shows that the effect only lasts for about two years.
So, if one could argue that putting children at risk for chickenpox just to protect adults was morally acceptable, the effect is so short-term that adults would essentially need to encounter a constant pool of chickenpox infected children. I swear this sounds like some surreal post-apocalyptic movie running on Netflix.
Many countries have rejected this use of children as a pool of chickenpox infection to prevent shingles in adults. Chickenpox vaccination recommendations and requirements exist in numerous countries: the USA, Australia, Greece, Germany, Japan, several areas of Italy, and few other countries. But too many countries do not pay for or recommend the vaccine, possibly to reduce financial obligations (I know, I’m a cynic in addition to being a scientific skeptic).
Eventually, as more and more children are vaccinated against chickenpox, the number of adults that are at risk of shingles slowly declines. Because, as I stated above, you need to contract chickenpox to get shingles. Once the first group of vaccinated children become adults, they don’t have to worry about shingles (although they might need boosters against chickenpox so they don’t become infected as adults from children who were never vaccinated).
And remember, there’s a shingles vaccine that will protect every single adult who had chickenpox as a child – it becomes even more morally ambiguous to use children as an immunization device when there’s a relatively safe and extremely effective vaccine against shingles. It’s incomprehensible to me that I’m even discussing this point on this blog – we should always protect children against deadly diseases. Protecting against both chickenpox and shingles makes sense.
Chickenpox and shingles – the summary
- Chickenpox is a serious disease. It has serious complications. The chickenpox vaccine prevents this.
- A chickenpox infection will lead to shingles during adulthood, because the same virus causes chickenpox, hides in the spinal cord, and then for unknown reasons reinfects the adult. A shingles vaccines prevents this.
- It is morally unjustified to use children as a pool of virus to “boost” the immune system of adults against shingles.
- In fact, the myth that the chickenpox “booster,” from children who have the disease, gives decades or even lifetime protection is patently false. The evidence says that it only protects adults for around two years.
- We can eventually eliminate shingles, by eliminating chickenpox. Maybe there will be a short-term increase in shingles, but in a couple of decades, no one is going to remember anything about shingles or chickenpox, because it will not be around much.
Sure, vaccinating children against chickenpox may temporarily increase the incidence of shingles, although we now have a vaccine against shingles. But that same vaccine also lowers the incidence of chickenpox in children, who then will never have to worry about shingles.
Are there any other questions?
- Despite both chickenpox and shingles being caused by the same exact virus, shingles was given a different name probably because it was originally thought to be two different viruses. However, in this case, herpes zoster is not a formal biological binomial nomenclature.
- Editor’s note – this article was first published in August 2015. It has been copyedited, reformatted, and generally cleaned up for readability.
- Ogunjimi B, Willem L, Beutels P, Hens N. Integrating between-host transmission and within-host immunity to analyze the impact of varicella vaccination on zoster. Elife. 2015 Jul 11;4. doi: 10.7554/eLife.07116. PubMed PMID: 26259874.
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