Porphyria and Vaccines

Brian Murphy, Ph.D. avatar

by Brian Murphy, Ph.D. |

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vaccine safety

People with rare diseases may well be concerned about the safety of vaccines, especially those newly developed against COVID-19.

Here is some information about vaccines, and risks associated with their use in people with porphyria.

What is Porphyria?

Porphyria is a group of diseases related to the production of heme. Porphyria can be divided into two major groups: acute and cutaneous (skin) porphyrias. People with acute porphyrias can experience acute porphyria “attacks,” episodes marked by sharp pain in the abdomen, back, or thighs, and frequently nausea, vomiting, and constipation. Feelings of confusion and disorientation are also known.

What are vaccines?

Vaccines are injected medicines that train the body to respond to pathogens, such as bacteria and viruses. Their use stimulates a person’s immune system to recognize and respond to these pathogens as if previously infected. This enable the immune system to quickly mount a response against such pathogens in the future.

Types of vaccines

The three main categories of vaccines available today are whole-pathogen, subunit, and nucleic acid vaccines.

Whole pathogen vaccines

Whole-pathogen vaccines use entire versions of viruses or bacteria. These pathogens can be either inactivated (killed) through the use of chemicals, heat, or radiation, or be live-attenuated and contain versions of living pathogens that are weakened so as not to cause disease.

Live-attenuated vaccines can provide life-long immunity after one or two doses, but have the potential to make people with weakened immune systems ill, since they involve small amounts of living pathogens. Examples of live-attenuated vaccines include those against measles, mumps, and rubella, smallpox, and chickenpox.

Inactivated vaccines carry less risk, but the immunity conferred typically is not as long-lasting and people may require periodic booster shots. Vaccines against polio, the flu, and rabies are examples of inactivated vaccines.

Subunit vaccines

Subunit vaccines involve the use of parts of a pathogens rather than an entire pathogen. These pieces may be a specific protein or sugar molecule that work to train the immune system to recognize the pathogen. Some of these vaccines may also contain inactivated toxins produced by bacteria, rather than the bacteria itself, to trigger an immune response.

Since they do not require intact pathogens, they can be given to most people, including those with chronic conditions or weakened immune systems.

The immune response they generate is typically weaker than the whole-pathogen vaccines, and may require boosters as well. Examples of subunit vaccines include those against shingles, pneumococcal, meningococcal, and hepatitis B.

Nucleic acid vaccines

Newer types of vaccines involve the use of nucleic acids. Nucleic acids are the building blocks of genetic material, such as DNA or RNA.

These vaccines are similar to subunit vaccines. The difference is that they use pieces of DNA or RNA to get a person’s own cells to produce pieces of the target virus or bacteria. Cells break down the genetic material, producing the pieces — known as antigens — that trigger an immune response.

One advantage to these vaccines is the ability to rapidly develop and manufacture them. Some of the currently approved vaccines against COVID-19 use this approach.

Should I be vaccinated if I have porphyria?

Attacks in people with acute porphyrias — including acute intermittent porphyria (AIP), hereditary coproporphyria (HCP), variegate porphyria (VP), and ALAD porphyria (ADP) — can be caused by a number of different triggers. There is no evidence suggesting that vaccinations pose additional risks to these people, however. Patients should receive vaccinations as recommended, because illnesses can put stress on the body that could lead to an acute porphyria attack.

The U.S. Food and Drug Administration and the Centers for Disease Control are advising patients with rare diseases to be vaccinated against COVID-19 infection.

The European Porphyria Network, UK Porphyria Medicines Information Service, and the American Porphyria Foundation also all specifically recommend that people with porphyria receive a COVID-19 vaccine, unless their physician recommends against it due to health concerns other than porphyria.

People with protoporphyria should also be given the hepatitis A and hepatitis B vaccines to better protect against further damage to liver. The excessive buildup of protoporphyrins in these patients can damage that organ, and additional stressors like hepatitis could lead to liver failure and the need for a liver transplant.


Last updated: Feb. 23, 2021


Porphyria News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.