• Ann Falco

An Additional COVID-19 Vaccine Dose has been Authorized for Immunocompromised Individuals


Currently, the Pfizer-BioNTech COVID-19 Vaccine has been available under emergency use authorization (EUA) in individuals 16 years of age and older, and the authorization was expanded to include those 12 through 15 years of age on May 10, 2021. The Moderna COVID-19 Vaccine is authorized for emergency use in individuals ages 18 and older. EUAs are used by the U.S. Food and Drug Administration (FDA) during public health emergencies to provide access to medical products, including vaccines, that may be effective in preventing, diagnosing, or treating a disease. EUAs are only used if the FDA determines that the known and potential benefits of a product when used to prevent, diagnose, or treat the disease, outweigh the known and potential risks of the product.


As the country enters another wave of the COVID-19 pandemic, health officials are closely evaluating the need for an additional vaccine dose. The FDA is aware that certain populations may benefit from receiving extra protection from COVID-19. As a result, the FDA has approved a third dose of the Pfizer-BioNTech or Moderna COVID-19 vaccine for those individuals that are considered immunocompromised.


The data from clinical studies suggest decreased vaccine effectiveness against COVID-19 infection, symptomatic disease, and hospitalization in several groups of immunocompromised individuals and the potential benefit of a third dose of COVID-19 vaccine in immunocompromised populations. Based on this information, the FDA amended the EUAs for both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine. This amendment allows for the use of an additional vaccine dose in certain immunocompromised individuals, specifically, solid organ transplant recipients or those patients who are diagnosed with conditions that severely harm the immune system. These vulnerable groups are at higher risk of severe disease and illness from COVID-19, so they should benefit greatly from a third vaccine.


People who are immunocompromised have a reduced ability to fight infections and other diseases and are especially vulnerable to infections, including COVID-19. Immunocompromised individuals are characterized by an impaired or weakened immune system. Therefore, the FDA evaluated information on the use of a third dose of the Pfizer-BioNTech or Moderna vaccines in these individuals and determined that the administration of a third vaccine dose may significantly increase protection in this population.


Furthermore, the CDC says that individuals who are moderate to severely immunocompromised are especially vulnerable to COVID-19 because they are more at risk of serious, prolonged illness. This population makes up about three percent of the adult population. While this may not seem like a lot of people, individuals with compromised or weakened immune systems may not build the same level of immunity from a two-dose vaccine series as compared to individuals who are not immunocompromised. Immunity to a disease is achieved through the presence of antibodies to that disease in a person’s system. Antibodies are proteins produced by the body that attack and destroy toxins or disease-carrying organisms. A type of immunity, called active immunity, results when exposure to a disease organism triggers the immune system to produce antibodies specific to that disease. Exposure to the disease organism can occur through infection with the actual disease (resulting in natural immunity), or the introduction of a killed or weakened form of the disease organism through vaccination (vaccine-induced immunity). In either case, if an immune person comes into contact with that disease in the future, the immune system will recognize it and immediately produce the antibodies needed to fight it. This process can be hampered or delayed in individuals that have weakened immune systems. Therefore, an additional dose is intended to improve the response to the initial vaccine series. The additional dose of the mRNA COVID-19 vaccine is recommended to be administered at least 28 days after the second dose to increase immunity.


The CDC is recommending that moderately to severely immunocompromised individuals receive an additional vaccine dose. The list of vulnerable populations is very specific and includes individuals who have:

  • Been receiving active cancer treatment for tumors or cancers of the blood.

  • Received an organ transplant and are taking medicine to suppress the immune system.

  • Received a stem cell transplant within the last two years or are taking medicine to suppress the immune system.

  • Moderate or severe primary immunodeficiency (such as DiGeorge syndrome or Wiskott-Aldrich syndrome).

  • Advanced or untreated HIV infection.

  • Active treatment with high-dose corticosteroids or other drugs that may suppress the immune response.


For those individuals who received either Pfizer-BioNTech or Moderna’s COVID-19 vaccine series, a third dose of the same mRNA vaccine should be used. The CDC recommends that an immunocompromised individual should not receive more than three mRNA vaccine doses until further evaluation of clinical data is performed. For clarification, the CDC explains that if the mRNA vaccine product given for the first two doses is not available or is unknown, either mRNA COVID-19 vaccine product may be administered. There is not enough data at this time to determine whether immunocompromised individuals who received the Johnson & Johnson’s Janssen COVID-19 vaccine also have an improved antibody response following an additional dose of the same vaccine.


This information is promising for many individuals who are immunocompromised as an additional dose may prevent serious and possibly life-threatening effects from COVID-19. This is especially important in those individuals who may not have responded to the initial vaccine series and have shown decreased effectiveness against COVID-19, severe symptoms, and have needed to be hospitalized. In ongoing clinical trials, the mRNA COVID-19 vaccines (Pfizer-BioNTech or Moderna) have been shown to prevent COVID-19 following the two-dose series. Limited information suggests that immunocompromised people who have low or no protection after two doses of mRNA vaccines may have an improved response after an additional dose of the same vaccine. This is hopeful evidence to help the fight against COVID-19, particularly as new variants of the virus emerge.

 

Speaking Plainly:

  • The emergency use authorizations (EUAs) for both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine have been amended to allow for the use of an additional dose in certain immunocompromised individuals.

  • People who are immunocompromised have a reduced ability to fight infections and other diseases and are especially vulnerable to infections, including COVID-19.

  • Immunocompromised individuals have an impaired or weakened immune system.

  • The additional dose of the mRNA COVID-19 vaccine is recommended to be administered at least 28 days after the second dose.

  • An additional dose may prevent serious and possibly life-threatening effects from COVID-19, especially in people who may not have responded to the initial vaccine series and have shown decreased effectiveness against COVID-19, severe symptoms, and have needed to be hospitalized.