On Aug. 13, 2021, the Centers for Disease Control and Prevention (CDC) made recommendations for a third dose of the mRNA COVID-19 vaccine following the initial two doses for those whose immune systems are moderately to severely compromised. People in this group are especially vulnerable to COVID-19 because they are at greater risk of serious and prolonged illness. They make up about 3% of the adult population. Emerging data show that immunocompromised individuals who have low or no protection following two doses of mRNA COVID-19 vaccines may have an improved antibody response after an additional dose of the same vaccine.

There is scientific consensus that widespread vaccination is the most effective tool to stopping the pandemic.

Who is eligible to receive a third COVID-19 vaccine?

Currently, the CDC is recommending the third dose for only moderately to severely immunocompromised persons. This includes those individuals 12 and older 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, Wiskott-Aldrich syndrome);
  • Advanced or untreated HIV infection;
  • Active treatment with high-dose corticosteroids (i.e., ≥20mg prednisone or equivalent per day) or other drugs that may suppress your immune response, such as alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, TNF blockers, and other biologic agents that are immunosuppressive or immunomodulatory. The UT Health Science Center San Antonio Vaccine Task Force recommends methotrexate also be included in this list, but not hydroxychloroquine.

Which brand of the COVID-19 vaccine should I get?

At this time, this emergency use authorization for a third dose of vaccine applies only to those who received an mRNA vaccine (Pfizer or Moderna). Preferably, your third dose should be the same vaccine brand you received for your first series of COVID-19 vaccines (Pfizer or Moderna). However, if that brand is not available, you can receive either mRNA vaccine as the third dose.

This emergency authorization does not apply to those who received the Johnson & Johnson (J&J) vaccine. It is expected that the need for a second dose in these persons will be addressed later after more data is available about antibody response following an additional dose.

How long should I wait to receive my third COVID-19 vaccine?

CDC recommends the additional dose of an mRNA COVID-19 vaccine (Pfizer or Moderna) be administered at least four weeks (28 days) after the second dose.

How do I get my third COVID-19 vaccine?

UT Health San Antonio patients who match eligibility criteria will soon be able to schedule their third dose through MyChart, their personal health record available digitally 24/7. Once available, a MyChart message with instructions on scheduling a third dose of the mRNA COVID-19 vaccine will be sent to our eligible patients. Communication to patients will be sent very soon.

It is anticipated that those who match eligibility criteria will soon be able to schedule their third COVID-19 vaccine at any public COVID-19 vaccine site. Visit San Antonio’s official COVID-19 vaccine website for the most current updates.

Where can I learn more about getting a third COVID-19 vaccine?

Visit the CDC.gov website to learn the most up-to-date information about third dose mRNA vaccines.