Third Dose of the Pfizer and Moderna COVID-19 Vaccines

On 12 August 2021 the FDA expanded the emergency use authorization for the Pfizer and Moderna COVID-19 vaccines to include a 3^rd injection for people whose immune system are moderately to severely impaired. 

The third dose of the vaccine must be at least 28 days after the second injection and has to be the same product as the first two doses.  Patients who received Pfizer vaccination, must receive the Pfizer vaccine as the third dose and patients who received the Moderna vaccination must receive the Moderna vaccine as their third dose.

For patients who received the Janssen COVID-19 Vaccine, additional injections are not authorized at this time. The FDA and CDC are actively working to provide further guidance for immunocompromised patients who received the Janssen vaccine.

Examples of conditions and treatments that qualify for a third dose of the Pfizer or Moderna vaccines are:

• 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 2 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 or other drugs that may suppress your immune response such as:
• Methotrexate
• Leflunomide
• Azathioprine
• Mycophenolate mofetil
• Cyclophosphamide
• Tacrolimus
• Voclosporin (Lupkynis)
• TNF inhibitors such as Enbrel, Humira, Cimzia, Simponi, Remicade
• Orencia
• Benlysta
• Actemra and Kevzara
• Saphnelo
• Rituxan
• Janus Kinase inhibitors such as Xeljanz, Olumiant, and Rinvoq
• Cosentyx and Taltz
• Stelara
• Tremfya

The risk of receiving a third dose of the Pfizer or Moderna COVID-19 vaccination appear to be similar to the first two injections.  There is limited data regarding the safety of the third vaccine dose. Serious side effects are rare, but can occur.

For my patients that received the Pfizer or Moderna COVID vaccine and are on immunosuppressive medications, like the ones above, I recommend receiving the third dose of their vaccine.  Patients who experienced significant side effects from the first two injections should discuss with their physician the pros and cons of receiving a third dose.