A. Recent data has shown that a third dose of either the Moderna or the Pfizer mRNA COVID-19 vaccine boosts a previous weak or undetectable vaccine response in some immunocompromised people.
This additional dose can help push the immune response to protective levels in some immunocompromised people. A third dose of the COVID-19 mRNA vaccine is now approved in the US, under EUA, for people with compromised immune systems.
➡️ TL;DR. The FDA expanded EUA approval for the Moderna and Pfizer mRNA vaccines to include a third dose for immunocompromised people. The ACIP met the next day to review: (1) data on the immune response to mRNA COVID-19 vaccines in immunocompromised people, and (2) the recent data on response to a third dose of COVID-19 mRNA vaccines in these people. The ACIP concluded that a third dose of either Pfizer or Moderna COVID-19 vaccine boosts a previous weak vaccine response in some immunocompromised people and can therefore offer more protection against COVID-19. A third dose of either the Pfizer or Moderna COVID-19 vaccine is now approved in the US for people with compromised immune systems.
What were the takeaways from the ACIP meeting?
➡️ Immunocompromised people are at higher risk for severe COVID-19. In addition, the SARS-CoV-2 virus may persist longer in immunocompromised people and may mutate, leading to new variants (Links to publications below).
➡️ Some immunocompromised people are less likely to make a good immune response to COVID-19 vaccines and are more likely to have breakthrough infections. In one report, 14 solid organ transplant recipients were diagnosed with COVID-19 approximately 23.5 days following vaccination and 50% of this group developed serious illness. An Israeli study reported breakthrough infections following vaccination in people who were immunocompromised (Links to these studies below).
➡️ Some immunocompromised people do not make a robust response to COVID-19 vaccines. For instance, one study found that only about 20% of organ transplant patients made an antibody response following COVID-19 vaccination.
➡️ A third dose of either the Pfizer or Moderna COVID-19 vaccines induced a more robust response in some immunocompromised people. Among those who did not make an antibody response to the initial vaccine, 33-50% made a response after the third dose (ACIP presentation – Link below).
Who is eligible for a third dose?
People who are immunocompromised due to the following conditions:
➡️ Active or recent treatment for solid tumor or hematologic malignancies (blood cancers)
➡️ Have recently received an organ or bone marrow transplant
➡️ Severe primary immunodeficiency (people who are missing a part of their immune system)
➡️ Advanced or untreated HIV infection
➡️ People on immunosuppressive medicines (some examples include: chemotherapy, high dose steroids, TNF-alpha inhibitors such as Humira, medicines that target immune cell populations such as Rituxan that depletes B cells).
➡️ Chronic conditions that affect the immune system such as chronic kidney disease or asplenia (missing spleen)
There are many more medical conditions and treatments that can result in immunosuppression. Whether you need a third dose is best determined following a conversation with your doctor.
🤔 Is a third dose safe?
Yes! Data shows that side-effects to a third dose of a COVID-19 mRNA vaccine are very similar to the side effects seen with the initial 2 doses (fever, arm pain, redness at the injection site, fatigue, headache – these reactions do not last long and are an indication that your immune system is working). No additional adverse reactions were reported.
🤔 When should the third dose be given?
The third dose should be given at least 28 days after the second dose. The third dose should match the first and second vaccine doses (i.e.; if you received the Pfizer vaccine, you should receive a third dose of the Pfizer vaccine). However, this may not be feasible in some cases. In such cases, it is okay to have a different vaccine as the third dose.
🤔 Will I be protected after the third dose?
The current data shows that some, but not all immunocompromised people made a good immune response to the third COVID-19 vaccine dose. Therefore, although some people may achieve protective levels of immunity following a third dose, not all immunocompromised people do. People who are immunocompromised should continue to stay safe by using a mask, and avoiding poorly ventilated spaces with large crowds.
💥 Overall, this is great news for immunocompromised people! Will a third dose or a booster be recommended for everyone else?
The CDC is currently evaluating data on the longevity of the immune response to COVID-19 vaccines in healthy people. While there has been some indication that boosters for the general population may be approved soon, these decisions have to be made after all relevant data has been studied carefully. The Nerdy Girls will provide updates as soon as specific information on ‘boosters for all’ is available!
Stay safe!
Love,
Those Nerdy Girls
Further reading:
Dear Pandemic: on approval of third dose for immunocompromised people
Dear Pandemic: on the need for a third dose in immunocompromised people
Persistence of SARS-CoV-2 in immunocompromised people
Immunocompromised people and variants
Breakthrough infections in immunocompromised people:
Development of COVID-19 Infection in Transplant Recipients After SARS-CoV-2 Vaccination
