A newly published and peer-reviewed study provides evidence that the risk of shingles (herpes zoster) increases after a COVID-19 infection. This supports numerous case reports that have been published that describe shingles in COVID-19 patients.
This post will examine the article. And this should provide you with more evidence that the COVID-19 and shingles vaccines are important to your health.
What are shingles?
One of the consequences of contracting chickenpox, caused by 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.
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” along the nerve bundles and causes a secondary infection with much more serious consequences to the patient.
This second infection is called herpes zoster, 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 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 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. Shingrix (a shingles vaccine available in the USA) is a relatively new, safe, and effective vaccine.
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 contract shingles.
Shingles and COVID-19 paper
In a paper published 9 March 2022 in Open Forum Infectious Diseases, Amit Bhavsar and colleagues performed a cohort study with a total of 394 677 individuals ≥50 years old with COVID-19 matched with 1 577 346 individuals without COVID-19. Mean follow-up time after COVID-19 diagnosis and baseline characteristics were balanced between cohorts.
Here are the key results:
- The researchers found that individuals diagnosed with COVID-19 had a 15% higher risk of shingles than those without COVID-19.
- Furthermore, they found a 21% higher risk of shingles following COVID-19 hospitalization compared to those without COVID-19.
The researchers concluded:
We found that COVID-19 diagnosis in ≥50-year-olds was associated with a significantly increased risk of developing HZ, highlighting the relevance of maintaining HZ vaccination.
Again, we don’t know why COVID-19 may increase the risk of shingles. It has been long speculated that stresses, such as an infection, may trigger the reactivation of the zoster virus leading to shingles.
There is some evidence that the mRNA COVID-19 vaccines from Moderna and Pfizer may increase the risk of herpes zoster. However, this study compared the risk of shingles against the flu vaccine, not to individuals who have had COVID-19. So, it is possible that the risk of shingles after the COVID-19 vaccine may be much lower than the risk of shingles after contracting COVID-19.
Summary
Nevertheless, it is clear that you can reduce your risk of shingles, a dangerous and painful disease, with two vaccines — one for COVID-19 and the other for shingles itself. I recently got my second booster for COVID-19 PLUS I got my first dose of the Shingrix vaccine. My immune system is ready to keep shingles in check.
Notes
Despite both chickenpox and shingles being caused by the same exact virus, shingles were given a different name, herpes zoster, probably because it was originally thought to be caused by a similar, but unrelated virus. However, herpes zoster is not a formal biological binomial nomenclature, and we now know that both chickenpox and shingles are caused by the same virus, Varicella zoster.
Citations
- Bhavsar A, Lonnet G, Wang C, Chatzikonstantinidou K, Parikh R, Brabant Y, Servotte N, Shi M, Widenmaier R, Aris E. Increased Risk of Herpes Zoster in Adults ≥50 Years Old Diagnosed With COVID-19 in the United States. Open Forum Infect Dis. 2022 Mar 9;9(5):ofac118. doi: 10.1093/ofid/ofac118. PMID: 35392454; PMCID: PMC8982770.
- Préta LH, Contejean A, Salvo F, Treluyer JM, Charlier C, Chouchana L. Association study between herpes zoster reporting and mRNA COVID-19 vaccines (BNT162b2 and mRNA-1273). Br J Clin Pharmacol. 2022 Feb 16. doi: 10.1111/bcp.15280. Epub ahead of print. PMID: 35174524.
