August 13, 2021 – CDC Director Rochelle Walensky, MD, has officially signed off on a recommendation by an independent panel of 11 experts to allow people with weakened immune function to get a third dose of certain COVID-19 vaccines.

The decision follows a unanimous vote Friday from a key CDC panel of experts, the Advisory Committee on Immunization Practices, which in turn came hours after the FDA updated its emergency use authorization for the Pfizer and Moderna COVID-19 vaccines.

About 7 million adults in the United States have moderate to severely impaired immune function because of a medical condition that they live with or a medication they take to manage a health condition.

People who fall into this category are at higher risk of being hospitalized or dying if they get COVID-19. They are also more likely to transmit the infection. About 40% of vaccinated patients who are hospitalized with breakthrough cases are immunocompromised.

Recent studies have shown that between one-third and one-half of immunocompromised people who didn’t develop antibodies after two doses of vaccine do get some level of protection after a third dose.

Even then, however, the protection immunocompromised people get from vaccines is not as robust as someone who has healthy immune function, and some committee members were concerned that a third dose might come with a false sense of security.

“My only concern with adding a third dose for the immunocompromised is the impression that our immunocompromised population will then be safe,” said Helen Talbot, MD, an associate professor of medicine at Vanderbilt University in Nashville.

“I think the reality is they’ll be safer, but still at incredibly high risk for severe disease and death,” she said.

In updating it’s EUA, the FDA stressed that even after a third dose, people who are immunocompromised will still need to wear a mask indoors, socially distance, and avoid large crowds. In addition, family members and other close contacts should be fully vaccinated to protect these vulnerable individuals.

J&J Not in the Mix

The boosters will be available to children as young as 12 years of age who’ve had a Pfizer vaccine or those ages 18 and older who’ve gotten the Moderna vaccine.

For now, people who’ve had the one-dose Johnson & Johnson vaccine have not been cleared to get a second dose of any vaccine.

FDA experts acknowledged the gap but said that people who had received Johnson & Johnson vaccine represented a small slice of vaccinated Americans, and said they couldn’t act before the agency updates its authorization for that vaccine, which the agency is actively exploring.

“We had to do what we’re doing based on the data we have in hand,” said Peter Marks, MD, director of the Center of Biologics Evaluation and Research at the FDA, the division of the agency that regulates vaccines.

“We think at least there is a solution here for the very large majority of immunocompromised individuals and we believe we will probably have a solution for the remainder in the not-too-distant future,” Marks said.

In its updated authorization, the FDA said the third shots were intended for people who had undergone solid organ transplants, or for people who have an “equivalent level of immunocompromise.”

The Details

Clinical experts on the CDC panel spent a good deal of time trying to suss out exactly what conditions might fall under the FDA’s umbrella for a third dose.

In a presentation to the committee, Neela Goswami, MD, an assistant professor of infectious disease and epidemiology at Emory University’s Rollins School of Public Health, stressed that the shots are intended for patients who are moderately orseverely immunocompromised in close consultation with their doctors, but that people who should qualify would include:

  • Those receiving treatments for solid tumors or blood cancers.
  • Those taking immunosuppressing medications after a solid organ transplant.
  • People who were within 2 years of receiving CAR-T therapy or a stem cell transplant.
  • People who have primary immunodeficiencies -- rare genetic disorders that prevent the immune system from working properly.
  • People with advanced or untreated HIV.
  • Those taking high-dose corticosteroids (more than 20 milligrams of prednisone or its equivalent daily), alkylating agents, antimetabolites, chemotherapy, TNF blockers or other immunomodulating or immunosuppressing biologics.
  • Certain chronic medical conditions may also qualify, such as chronic renal disease or asplenia — living without a spleen.
  • People receiving dialysis may also need a third dose

In discussion, CDC experts clarified that these third doses were not intended for people whose immune function had waned with age, such as elderly residents of long-term care facilities, or people with chronic diseases like diabetes.

The idea is to try to get a third dose of the vaccine they’ve already had — Moderna or Pfizer -- but if that’s not feasible, it’s fine for the third dose to be different. The third dose should be given at least 28 days after a second dose, and ideally, before the initiation of immunosuppressive therapy.

CDC participants in the meeting said the agency would post updated materials on its website to help guide doctors on exactly who should receive third doses.

Ultimately, however, the extra doses will be given on an honor system, no prescriptions or other kinds of documentation will be required for people to get a third dose of these shots.

"Peace of Mind"

In public testimony, Heather Braaten , a 44-year-old being treated for ovarian cancer, said she was grateful to have gotten two shots of the Pfizer vaccine last winter, in between rounds of chemotherapy, but she knew she was probably not well protected. She said she’d become obsessive over the past few months reading medical studies trying to understand her risk.

“I have felt distraught over the situation. My prognosis is poor. I most likely have about 2 to 3 years left to live, so everything counts,” Braaten said.

She said her life ambitions were humble. She wants to visit with friends and family and not have to worry that she’ll be a breakthrough case. She wants to go grocery shopping again and “not panic and leave the store after 5 minutes.” She’d love to feel free to travel, she said.

“While I understand I still need to be cautious, I am hopeful for the peace of mind and greater freedom a third shot can provide,” Braaten said.

In the second half of the meeting, the CDC also signaled that it was considering the use of boosters for people whose immunity might have waned in the months since they had completed their vaccine series.