COVID-19 Vaccines and Alopecia Areata: What is the Relationship?

By Anthony Gilding HBSc(c), Director of Science & Research at CANAAF

It has been a little over a year since COVID-19 vaccines have been administered to Canadians with the intention of slowing the spread of COVID-19 and reducing the risk of severe illness. Given the novel nature of this vaccine, many Canadians with Alopecia Areata (AA) are apprehensive about getting the shot out of fear that it may worsen their hair loss, or cause AA in someone who did not have it before. This article will highlight how the COVID-19 vaccine works and discuss its relationship with AA.

The two vaccines currently available to most Canadians are Pfizer-BioNTech and Moderna, both of which are mRNA vaccines. mRNA is a set of genetic instructions that are translated into a functional protein for the body to use. The specific type of mRNA in the vaccine codes for the spike protein on the SARS-CoV-2 virus (the virus responsive for causing COVID-19). Think of an mRNA vaccine like a recipe for the spike protein. Once injected into our arms, the vaccine has the following effects on the body:

1) Our cells read the mRNA, produce the spike protein and display it on their surface.

2) The cells of our immune system see the spike protein and interact with it. The result is the formation of specialized immune cells that produce antibodies designed to recognize and target the spike protein. Antibodies are proteins produced by the immune system that are used to prevent harmful pathogens (viruses, bacteria, etc.) from making us sick.

Once we develop antibodies against the spike protein, we are well-equipped to fight the real virus. If one manages to come in contact with COVID-19 after being vaccinated, the antibodies will recognize the spike protein on the virus and destroy it before it has a chance to enter our cells and make us sick.

1. “The mRNA will incorporate itself into my DNA and cause unwanted changes”

This is completely false. Once read by our cells, the mRNA is degraded. mRNA is not able to combine itself with DNA – these are two distinct biological molecules.

2. “I don’t need the vaccine; my natural immune system will protect me”  

While it is true that we have an innate immune system that provides an immediate response to invading pathogens, it does not provide the strongest response to pathogens it has not seen before, like the COVID-19 virus. Without antibodies generated by the vaccine, you do not have the strongest protection possible and are at risk of developing severe illness.

In summary, the mRNA COVID-19 vaccine works by stimulating our bodies to produce antibodies against the virus’ spike protein. If the real spike protein enters our body, our immune systems will immediately recognize it and destroy the virus before it can do any harm. The vaccine does not have any other biological effect on the body.

The short answer to this question is that we do not have any data to suggest that the vaccine causes AA or worsens hair loss in people with AA.

Some people have referenced a case report by Rossi et al. (2021) which described the recurrence of AA in 3 people after the first dose of the vaccine. In this specific case, all 3 people had a history of AA, meaning they already had AA but did not have any active hair loss at the time. 2-3 weeks after the first dose, these people noticed an increase in their hair loss.

The important thing to consider in this case is that this is only 3 out of the hundreds of thousands of people with AA who received their COVID-19 vaccine without issue, thus this information cannot be generalized to the public. The most likely explanation in this case is that the autoimmunity causing AA was exacerbated, but not caused by the healthy immune response to the vaccine. It is imperative to note that this can theoretically happen with any vaccine – not just the COVID-19 vaccine, but this does not routinely happen and should not be a reason to avoid vaccination. The risk of severe illness and death caused by the infection is much worse than the low risk of AA worsening after vaccination.

AA is very unpredictable and is known to come and go in cycles. Therefore, try as we might, we cannot fully attribute any activity, vaccination or otherwise, to worsening hair loss as there is always the possibility that it would happen on its own. Think of it like shaking a tree in the fall. You may cause some leaves to fall off, but this was likely to happen any way given the change of season.

In short, the COVID-19 vaccine has been proven to be safe and effective in reducing the transmission of the virus as well as severe illness or death caused by the infection. People considering the vaccine are encouraged to speak with their healthcare providers and critically review any information they receive from the internet or by word-of-mouth. For specific concerns regarding the COVID-19 vaccine and AA, you are encouraged to speak with your dermatologist or dermatology nurse practitioner.

Take care and stay safe!