A large retrospective cohort study conducted by researchers in Germany and the University of Virginia compared the incidence of shingles among individuals who did and did not get a Covid-19 shot and found a statistically significant difference providing evidence for an association between Covid vaccinations and increased risk for developing shingles or herpes zoster (HZ). The authors pointed out that “an association of HZ with Covid vaccination has been reported worldwide” and concluded that “the eruption of HZ may be a rare adverse reaction to Covid shots,” noting that varicella zoster (VZ), or chickenpox, reactivation is a well-established phenomenon both with infections and with other vaccines.”
Shingles is caused by the HZ virus and appears as a blistering, painful rash that occurs when VZ, the virus that causes chicken pox, is reactivated and moves to the nerves of the skin, where it produces the painful shingles rash. Like other herpes viruses, VZ lays dormant in the nervous system until it is reactivated.1 Elderly persons 60 years and older are more likely to develop shingles, especially if they are not asymptomatically boosted throughout life by coming in close contact with children recovering from chicken pox infections.2 3 About 20 percent of those who recover from shingles suffer from post-herpetic neuroglia lasting from months to years.4
Certain events can trigger the onset of shingles, including the natural decline of immunity that comes with age, stress, drugs and vaccines.5 Recently, there have been wide-spread reports of VZ virus reactivating after receiving a Covid shot, especially with messenger RNA (mRNA) technology such as Pfizer/BioNTech’s Comirnaty and Moderna/NIAID’s Spikevax biologics.6
Some experts have speculated that the link between the reactivation of varicella zoster and Covid shots could be due to the changes in immune system function after vaccination. Risk factors for getting shingles include being older, undergoing severe stress and a weakened immune system.
Study Included Millions of People Who Did and Did Not Get Covid Shots
The study looked at real world data of 1,095,086 people, who received a Covid shot compared to 16,966,018 people who did not get the shot and visited a clinic within the TriNetX Global Health Research Network database. The Network database aggregates data from multiple healthcare centers across 19 countries and the subjects were matched for age and gender. The vaccinated group visited the clinic for the purpose of being vaccinated, while the unvaccinated group went to the clinic for another reason.
Study results revealed that the vaccinated group had a 20 percent chance of coming down with shingles post Covid vaccination while the unvaccinated group had 11 percent odds of developing the painful virus within 60 days of visiting the clinic. The study authors concluded that the difference was statistically highly significant.7
The authors wrote:
Consistent with the hypothesis, a higher incidence of HZ was statistically detectable post-Covid-19 vaccine. Accordingly, the eruption of HZ may be a rare adverse drug reaction to Covid-19 vaccines.8
SARS-CoV-2 Infection Can Also Trigger Shingles
The SARS-CoV-2 virus, which is known to cause lung and heart problems, has also been found to cause shingles. Numerous case reports indicated that SARS-CoV-2 infections could trigger reactivation of the VZ virus and researchers have hypothesized that it is linked to the physical and psychological stress of the body trying to deal with the SARS-CoV-2 infection.9
The journal Open Forum Infectious Diseases published a large study in 2022 comparing 400,000 people who had SARS-CoV-2 to 1.6 million people who have not had the viral infection. Adults over the age of 50 who had been infected with SARS-CoV02 had a 15 percent higher chance of coming down with shingles with the next six months. Patients who had severe cases of Covid requiring hospitalization had a 21 percent risk of developing shingles.10
Another Study Indicates Shingles May be a Side Effect of COVID Shots
A study published by Israeli researchers in 2021 in the British Society of Rheumatology showed that shingles could be a side effect of Covid shots. The observational study evaluated adverse events following Covid vaccination in subjects suffering from autoimmune inflammatory rheumatic disease (AIIRD) and compared 491 patients with AIIRD to 99 control subjects, all of whom received a Covid shot in two rheumatology departments in Israel.11 12
In the AIIRS group, six female subjects developed shingles post vaccination (1.2 percent) compared to zero subjects developing shingles in the control group. Five of the six women came down with shingles after a first Covid shot and one after the second dose. All shingles cases were mild and resolved within six weeks.13
Patients Who Received Three Different COVID Shots Developed Shingles
This year, the journal Family Practice also published a report of three case studies of patients (one male, two females), who came down with shingles three to 13 days after receiving three different types of Covid shots.14 All three patients were between 67-79 years old, were overweight or obese, and had hypertension and dyslipidemia (abnormal amount of lipids in the blood) in their medical history. One patient had recovered from a SARS-CoV-2 infection a year before receiving a Covid shot and did not develop shingles following that Covid infection. All patients received different Covid shots, including Comirnaty, Spikevax, and AstraZeneca/Oxford University’s Vaxzevria, and all three completed the series of three doses despite developing shingles after the first dose.15
Study authors hypothesized surmise that “an altered immune landscape involving cellular immunity might be implicated in this phenomenon.”16
Immune System Depression Post Vaccination May Set Stage for Reactivation of Varicella Virus
A May 2022 study looked at 10 case studies of shingles that occurred one to three weeks after Covid vaccination. The authors speculated that, similar to Covid infections, transient immunomodulation following vaccination could result in reactivation of the HZ virus. More specifically, they proposed that lowered counts of CD4+ T cells, CD8+ T cells, and natural killer cells could set the stage for reactivation of HZ and development of shingles.17
Complications from shingles include postherpetic neuralgia; ophthalmicus (painful rash in the fifth cranial nerve shared by the eye); acute retinal necrosis (death of eye tissue); Ramsay Hunt syndrome (facial paralysis near the ear and hearing loss); Bell’s palsy and Guillain-Barré syndrome, which involve paralysis of the face or limbs); encephalitis (brain inflammation), aseptic meningitis (inflammation of lining of brain) and myelitis (inflammation of the spinal cord); peripheral motor neuropathy (damage to nerves that control muscles), and bacterial skin infection.18
The study authors noted that reactivation of the herpes virus is a rare complication of other vaccines, most notably influenza, hepatitis A, rabies, Japanese encephalitis and yellow fever vaccines and that, while research is limited so far, the Covid shots can likely be added to this list. They warned:
Vaccination initiatives for Covid-19 are in full swing. Given the large number of people who will be vaccinated against SARS-CoV-2, a possible causal link could result in a large number of cases among the elderly, with devastating consequences. Post-marketing surveillance procedures must be in place, and ongoing vaccination safety assessments are critical for detecting any occurrence that could reduce the projected benefits and, as a result, taking obligatory action to reduce hazards amongst vaccinated people…Our findings necessitate a further investigation of the possible relationship between Covid-19 and herpes zoster in the context of vaccinating elderly and/or immunocompromised people.19
A Decrease in Lymphocytes May Play Role in Shingles Post Vaccination
Covid is known to cause lymphopenia, a condition whereby blood doesn’t have a sufficient number of lymphocytes (white blood cells) to help the immune system protect the body from infection.20 21 Symptoms of lymphopenia may include swollen lymph nodes, spleen and joints; fever; skin ras; frequent infections or inability to heal from an infection. All types of white blood cells decrease but CD4+ and CD8+ lymphocytes tend to decrease the most and this T-lymphocyte impairment could lead to shingles.
The Pfizer/BioNTech Covid mRNA shot trials showed that there was a dose-dependent decrease in lymphocytes in the first few days after receiving the shot. At the currently used dose, up to 46 percent of the trial study participants had a transient decrease in lymphocytes count to below 1×10.9 The trial authors speculated that it is during this window of time when lymphocyte counts are lowered that the VZ virus can reactivate in the body.22
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1 Seladi-Shulman J, Goodwin M. Can a COVID-19 Vaccine Increase Your Risk of Shingles? Healthline Oct. 14, 2022.
2 Raines K, Fisher BL. CDC Accused of Manipulating Shingles Data. The Vaccine Reaction Aug. 19, 2019.
3 Forbes H, Douglas I, Finn et al. Risk of herpes zoster after exposure to varicella to explore the exogenous boosting hypothesis: self controlled case series study using UK electronic healthcare data. BMJ 2020; 368: 16987.
4 Agrawal S, Verma K, Verma I et al. Reactivation of Herpes Zoster Virus After COVID-19 Vaccination: Is There Any Association? Cureus May 2022; 14(5): e2519.
6 Seladi-Shulman J, Goodwin M. Can a COVID-19 Vaccine Increase Your Risk of Shingles? Healthline Oct. 14, 2022.
7 Hertel M, Heiland M, Nahles S et al. Real-world evidence from over one million COVID-19 vaccinations is consistent with reactivation of the varicella-zoster virus. Journal of the European Academy of Dermatology and Venereology Apr. 26, 2022; 36; Iss. 8.
9 van Dam CS, Schaar J, Al-Dulaimy M et al. Herpes zoster after COVID vaccination. Int J Infect Dis October 2021 169-171.
10 DeLaire M. Risk of shingles rises after COVID-19 infection: study. CTV June 28, 2022.
11 O’Laughlin F. Study: Shingles may be side effect of COVID-19 vaccine. WHDH Apr. 20, 2021.
12 Furer V, Zisman D., Kibari, A. et al. Herpes zoster following BNT162b2 mRNA COVID-19 vaccination in patients with autoimmune inflammatory rheumatic diseases: a case series. Rheumatology, Vo. 60, Issue SI, October 2021.
14 Saraiva A, Viera AR, Marinho MC et al. Varicella zoster virus reactivation following COVID-19 vaccination: a report of 3 cases. Family Practice October 2022; 39(5).
17 Agrawal S, Verma K, Verma I et al. Reactivation of Herpes Zoster Virus After COVID-19 Vaccination: Is There Any Association? Cureus May 2022; 14(5): e2519.
20 What is Lymphopenia? National Heart, Lung and Blood Institute May 31, 2022.