An observational study conducted in Israel has revealed a potential risk for herpes zoster activation following vaccination with Pfizer’s experimental mRNA COVID-19 vaccine BNT162b2.1 2 Herpes zoster, commonly known as shingles, is caused by reactivation of the varicella zoster virus that causes chickenpox. After recovery from natural chickenpox infection or vaccination with the live attenuated virus vaccine Zostavax® (which has now been discontinued in the U.S.),3 the virus continues to circulate in the body, where it likely remains dormant for life.
Varicella Zoster (Chickenpox) Virus Can Be Reactivated Years Later
However, the dormant varicella zoster virus can be reactivated years later, manifesting as herpes zoster or shingles, a painful rash with blisters that generally develops along one side of the face or torso.4 5 It has not been established what causes the virus to reactivate, but several potential triggers have been identified, including re-exposure to the varicella zoster virus by coming in close contract with someone infected with chickenpox, acute or chronic diseases or infections, some medications, and emotional or physical stress.6
Typically, the rash and blisters associated with herpes zoster clear up in a week or two, but more serious repercussions such as post-herpetic neuralgia (nerve pain) can persist for months or years. Other rare complications such as eye involvement leading to blindness, can be permanently debilitating.7
No COVID-19 Vaccine Safety Data in Those With Autoimmune Conditions
The safety profile of COVID-19 vaccination has not been fully assessed in patients with pre-existing autoimmune inflammatory rheumatic diseases (AIIRD) because immunosuppressed people were not included in studies before the U.S. Food and Drug Administration (FDA) granted three vaccine manufacturers an Emergency Use Authorization (EUA) to distribute the experimental COVID-19 vaccines in the U.S. To evaluate the effects of COVID-19 vaccination on that population, researchers from two medical centers, the Tel Aviv Medical Center and the Carmel Medical Center in Haifa, studied post-vaccination adverse effects in 590 subjects, 491 with AIIRD and 99 controls.8
All six occurrences of symptomatic herpes zoster occurred in the AIIERD cohort (6 of 491, or 1.2 percent), and there were no cases in the control group. Although herpes zoster generally affects people older than 50, half of the six affected women in the study group were much younger (ages of the patients were 36, 38, 44, 56, 59 and 61) and all had stable AIIRD (rheumatoid arthritis in four cases, Sjogren’s syndrome in one and and undifferentiated connective disease in the sixth). One patient had previously been vaccinated against shingles. 9
According to Victoria Furer, MD, lead author of the Israeli study, the development of herpes zoster following COVID-19 shots among adults suffering with AIIRD was unexpected. The relatively young ages of the study subjects and the fact that most of them had mild autoimmune disease requiring little or no treatment meant that, “they should not have been at increased risk for developing herpes zoster.”10
Symptoms developed soon after the first vaccine dose in five cases and after the second dose in the sixth. One rheumatoid arthritis patient developed herpes zoster ophthalmicus without corneal involvement. All others had mild symptoms. Four of the five subjects who had only had one vaccine dose before developing herpes zoster symptoms completed the second dose with no further reactions, and one subject refused the second dose.11 12
Link Between COVID-19 Vaccine and Shingles Previously Dismissed
A possible association between COVID-19 vaccination and herpes zoster had previously been speculated about in the press, although infectious disease professionals denied there was any evidence of a connection.13 Dr. Furer said that, since the study findings were published in the peer-reviewed Rheumatology journal on April 12,14 she has “received emails from patients around the world that [sic] got [herpes zoster] after the vaccine…It seems that the reason is that there is some association.”15
Dr. Furer added that, while it is not yet clear whether the vaccine caused the shingles, “We can say it might be a trigger in some patients.” She advised that further research is needed and suggested that, “one implication could be that patients with autoimmune inflammatory rheumatic diseases be encouraged to get vaccinated against herpes zoster before getting their COVID-19 shot.”16
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