What our experts say
Ramsay Hunt Syndrome (RHS) is a rare complication of a very common virus: Varicella Zoster Virus (VZV). VZV is the virus responsible for Chickenpox and Herpes Zoster (more commonly known as Shingles).
This virus remains inactive in the human body after an initial exposure, and can later become reactivated, often causing a painful rash (Shingles). When this happens, you are at risk of RHS. So for example, if you had Chickenpox as a young child, VZV will stay dormant in you and can be reactivated to cause Shingles and then Ramsay Hunt – though this chain of events is very rare.
During the pandemic, scientists have been investigating the patterns of this rare disease, and examining if there is a relationship to COVID-19 vaccines.
The U.S. Centers for Disease Control and Prevention (CDC) state that one in three people (about 33%) will have Shingles at some point during their lifetime. Although this disease is known to affect older individuals, the United States has had an unexplained increase of cases in young and middle aged adults since 2008.
A two-dose Shingles vaccine is available and recommended for adults that are 50 years of age and older, and younger individuals who are known to have a weakened immune system. This is because this group is at a higher risk of getting severe shingles that can lead to hospitalization, which happens in up to 4% of all patients.
There are a handful of case reports about individuals who developed Ramsay Hunt syndrome following a COVID-19 vaccination. The most commonly cited one is about a case in Hong Kong published in December 2021 titled “Ramsay Hunt syndrome following COVID-19 vaccination.” Other similar reports have documented cases of individuals developing the Shingles or Ramsay Hunt specifically following a COVID-19 vaccine.
In January 2020, a case of Ramsay Hunt Syndrome was reported in Hong Kong. The authors who reported this case claimed it to be the first reported case of RHS after a COVID-19 vaccination. In the same month a Spanish paper published a similar diagnosis in a 78 year old woman.
The purpose of these papers is to report the observation of these cases; they do not establish any causal relationship between the vaccine and RHS.
Because RHS and Shingles are a reactivation of a VZV infection, seeing these conditions after some vaccinations is not uncommon.
One theory behind why vaccines (not just COVID-19 vaccines) could possibly contribute to a reactivation of Shingles or Chickenpox is because the immune system is slightly weakened. You could also think of it as the immune system being distracted with reacting to the vaccine and making antibodies, making it potentially easier for suppressed viruses to reactivate.
This same logic applies to anything that weakens the immune system or stresses the body, including psychological stress. This phenomenon has also been seen with other conditions such as epstein–Barr virus (also known as mono) as well as other vaccines like the influenza and hepatitis B vaccines.
This theory has not been proven, and research overall has not proven that this reactivation was actually because of the vaccinations versus just coincidence. These are just cases, not large randomized studies that can prove causation.
In summary, current research does not confirm that RHS is a side effect of COVID-19. As a result, any unestablished potential risks of COVID-19 vaccines reactivating Shingles or RHS is outweighed by the established known benefits of COVID-19 vaccines. Researchers continue to recommend vaccination against COVID-19 vaccines when eligible. Additionally, they also recommend that more studies be conducted to examine the relationship as vaccination rates continue to rise.
Context and background
When someone gets an infection by Varicella Zoster Virus (VZV), like chickenpox, it usually resolves on its own within two to four weeks. After the condition improves, the virus can hide from our immunity in the nervous system, where it remains inactive. Think of it as a virus that goes to sleep or hibernates.
Shingles occurs when this sleeping virus is reactivated, and most often happens among older people. Most commonly Shingles leads to a painful skin rash. This condition also has a characteristic pattern of affecting the skin in “stripes.”. The reason for this pattern is that the rash follows the nerves that connect to the human skin.
To understand how this happens, imagine the body’s central nervous system (which is the brain and spine) as a central power station. Branches of nerves leave this central nervous system and connect to the skin in an organized manner, similar to how power cables connect to different parts of a city, forming an electrical grid.
Similarly to a city, each branch (or metaphorical power cord) will light up one defined part of the skin with sensation, as long as it remains healthy. If that branch is damaged, that patch of the skin “loses power” similar to how a part of a city would go dark if its power supply was damaged. The virus commonly affects the patch of the skin that’s related to the nerve supplied by the area it lives, hiding from the immune system. In extreme cases where the immunity is weakened, it can spread to affect more parts of the body.
Ramsay Hunt Syndrome happens when one of the branches from the nervous system that supplies the face, known as the facial nerve, is affected by VZV. This means that you can only get this condition if your body already has the dormant virus hiding in it. Despite the theories about why VZV reactivates in the body, the real reason why this happens in RHS is unknown.
The condition can lead to varying degrees of paralysis of the muscles of the face, a rash around the ear, and hearing loss. However, not all patients experience all of the symptoms, and they do not happen together, which makes it hard to diagnose. The majority of people who get RHS recover completely; however, in some cases, the condition can have long lasting nerve damage.
RHS has gained recent media attention because Justin Bieber spoke out about having it, which was followed by a surge in social media posts falsely linking RHS to COVID-19 vaccines.
- Shingles (Herpes Zoster) (U.S. Center for Disease Control and Prevention)
- Varicella (World Health Organization)
- Ramsay Hunt Syndrome (National Library of Medicine)
- Ramsay Hunt syndrome following COVID-19 vaccination (British Medical Journal)
- Ramsay Hunt syndrome following mRNA SARS-COV-2 vaccine (Enfermedades Infecciosas y Microbiología Clínica)
- Herpes zoster following COVID-19 vaccination in an immunocompetent and vaccinated for herpes zoster adult: A two-vaccine related event? (Metabolism Open)
- Ramsay Hunt Syndrome (NORD)
- Varicella zoster virus-induced neurological disease after COVID-19 vaccination: a retrospective monocentric study (Journal of Neurology)
Used with Permission from Health Desk, a public health hub that explains emerging COVID-19 science.