COVID-19 vaccines: what you need to know

This page was updated on October 15.

FDA announcement

On August 12, 2021, the FDA approved a third “booster” dose of the Pfizer and Moderna COVID-19 vaccines for people with weakened immune systems (immunocompromised). Early data has shown this extra dose can help provide additional protection for immunocompromised patients.

What this means for you

On August 13, 2021, the Advisory Committee on Immunization Practices (ACIP) announced who qualifies as moderately to severely immunocompromised and should receive an additional dose. This includes people who have:  

  • Actively receiving 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

Stay safe

In the meantime, please continue to stay safe by avoiding crowds, avoiding indoor gatherings with people outside of your household, wearing your mask and getting tested for COVID-19 if you develop symptoms. Please also encourage all of your family members, friends and household contacts get vaccinated.

Frequently asked questions about the COVID-19 vaccine

What should patients with cancer do to protect themselves from COVID-19?

SCCA strongly recommends continued vigilance for cancer patients, even those who are fully vaccinated. As cancer patients are at increased risk for COVID-19 complications and may not be as well protected from the available vaccines, patients should continue to wear masks, maintain social distancing, avoid crowds and follow guidelines and other pre-vaccine recommendations for COVID-19 prevention.

It is important that your caregivers, household members and other close contacts are immunized to ensure that you are protected. 

I am immunocompromised and I received a full COVID-19 vaccine series. How do I know I am protected? Should I get an antibody test to check my immunity?

We do not recommend checking antibodies because we do not know what level of antibody is considered protective, even in the general population. Antibody tests also do not measure other types of vaccine responses, like T-cell responses, that play a role in immune protection. This is consistent with current Centers for Disease Control (CDC), National Comprehensive Cancer Network (NCCN), and Food and Drug Administration (FDA) guidance.

More research is currently being done to determine the best immune measures to indicate protection and to better understand how well cancer patients are protected when they get vaccinated. 

I am a cancer patient who has not been vaccinated – what should I do?

Talk to your care team about getting vaccinated. It is recommended that all cancer patients get vaccinated against COVID-19, unless they currently have low counts due to chemotherapy (e.g., post-leukemia therapy), or if they have received a bone marrow transplant or CAR-T cell therapy within the last three months. 

It is also important to talk to your family, close contacts and caregivers about getting vaccinated, as this will also help to protect you from getting exposed to the virus. 

Should I get a booster shot?

Talk with your clinical team about getting a third dose (“booster”) if you meet the following criteria:   

  1. Immunocompromised and received the Pfizer or Moderna COVID-19 vaccines initially
  2. Received the Pfizer or Moderna COVID-19 vaccines initially  
  3. Received the Pfizer COVID-19 vaccine initially and met one of the following criteria:
    • Aged 65 years and older
    • A resident aged 18 years and older in long-term care settings
    • Aged 50–64 years with underlying medical conditions
    • Aged 18–49 years with underlying medical conditions
    • Aged 18–64 years at increased risk for SARS-CoV-2 exposure and transmission because of occupational or institutional setting

At this time, people who received the Johnson & Johnson/Janssen vaccines are not eligible for third dose (“booster”) shots. Moderna third doses are only potentially available for those who are immunocompromised and are not currently available in our clinic.

Does my vaccine protect me against variants?

From what we currently know, based on studies done in the general population, the mRNA and J&J/Janssen vaccines are highly protective in preventing severe disease, hospitalization and death from the Delta variant, the most common variant in the United States. It is important to recognize that no vaccine is 100% effective at preventing infection, so even if you are fully vaccinated, we recommend masking, avoiding crowds and social distancing from those outside your household to help prevent exposure to COVID-19. In addition, if you develop symptoms post-vaccine, tell your care team and get tested for COVID-19.  

We are continuing to monitor the situation regarding new variants and will provide additional information as it becomes available. 

How long is my COVID-19 vaccine effective for?

We do not know, as this is still being researched. Recent studies for the Pfizer and Moderna mRNA vaccines have shown that protection remained high for up to nine months (the time period for which data are currently available) after the second shot for people without cancer, but recent data has suggested potential benefits of a third dose 6 months after the initial series for some populations of patients. Longer-term follow-up studies are needed to determine how long immunity lasts. 

The length of protection for cancer patients has not been adequately studied, but we expect that the response will not be as robust. We recommend continuing to mask up, avoiding crowds and social distancing from those outside your household to help prevent exposure to COVID-19. 

Can I enroll in any research studies?

For patients who are planning to get vaccinated but have not yet received a dose, Fred Hutch is participating in a study of COVID-19 vaccine responses in patients who are within one year of (autologous or allogeneic) hematopoietic cell transplant (HCT) or CAR T-cell therapy. Speak to your care team for more information. 

There are additional trials for patients who develop COVID-19, so if you become positive and are interested in participating in a study, contact your provider to ask if you might be eligible for these trials. 

SCCA COVID-19 vaccine tracker

This data updated October 22, 2021

Total vaccines


People who have received
their first dose


People who have received
their second dose


People who have received
their third dose


covid vaccine infographic

The information presented in this page is subject to change pending guidance from the CDC, WHO and/or Public Health – Seattle & King County. Some of the information on this page has been adapted, with permission, from UW Medicine’s COVID-19 Vaccines webpage.

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