Some people with weakened immune systems can now receive a third dose of either the Pfizer-BioNTech or Moderna coronavirus vaccines to boost their protection against COVID-19.
The U.S. Food and Drug Administration amended the emergency use authorization late Thursday, noting that additional doses are allowed only for “certain immunocompromised individuals, specifically, solid organ transplant recipients or those who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise.”
An advisory committee within the Centers for Disease Control and Prevention voted to officially recommend the third shot on Friday.
The agency added a list of conditions that could make someone eligible for the additional dose, including:
—People who have been receiving “active cancer treatment” for tumors or blood cancers
—People who received an organ transplant and are taking medicine that suppresses their immune system
—People who received a stem cell transplant within the last two years or are taking medicine that suppresses their immune system
—People with moderate or severe “primary immunodeficiency,” such as those with DiGeorge syndrome and Wiskott-Aldrich syndrome
—People with advanced or untreated HIV
—People who are actively taking treatment with high-dose corticosteroids or other drugs that may suppress their immune response
The third dose is to be given at least a month after a person receives their second shot, and it should be the same vaccine as their first two doses.
People with weakened immune systems who received the one-dose Johnson & Johnson COVID-19 vaccine are not yet allowed to receive an additional shot, officials said, citing a lack of data.
CDC experts said all immunocompromised people, including those who get an additional shot, should continue practicing other preventive measures, such as hand washing, mask wearing and physical distancing.
About 7 million adults in the U.S. are immunocompromised, including people with cancer, HIV and those on certain medications such as chemotherapy and high-dose corticosteroids. It’s unclear what other conditions besides solid organ transplant recipients make someone eligible for a third dose.
“The country has entered yet another wave of the COVID-19 pandemic, and the FDA is especially cognizant that immunocompromised people are particularly at risk for severe disease. After a thorough review of the available data, the FDA determined that this small, vulnerable group may benefit from a third dose of the Pfizer-BioNTech or Moderna Vaccines,” acting FDA Commissioner Dr. Janet Woodcock said in a statement. “Today’s action allows doctors to boost immunity in certain immunocompromised individuals who need extra protection from COVID-19.”
“As we’ve previously stated, other individuals who are fully vaccinated are adequately protected and do not need an additional dose of COVID-19 vaccine at this time,” Woodcock added.
The FDA and CDC’s push to give people with weakened immune systems extra protection is based on several studies that have shown some in the group may not develop as robust antibody responses to the vaccines — or any at all. They are also more likely to get severely ill from COVID-19 and spread it to others.
Immunocompromised people are more likely to have breakthrough infections, too, which are those that occur two or more weeks after complete vaccination. One U.S. study found that among 45 patients hospitalized with breakthrough cases, 20 of them (44%) were immunocompromised.
A non-peer reviewed study posted in June found that among a group of healthy people, 98% produced antibodies after vaccination, while only 37% of organ transplant patients, 55% of blood cancer patients, 82% of solid tumor cancer patients and 84% of those with autoimmune disorders developed the protective proteins.
Strikingly, about 95% of people with HIV developed antibodies after getting their shots.
People who received their organ transplant less than a year ago were less likely to respond to vaccination. Among transplant patients, those who received new lungs had the poorest immune response (22%), while people who got new livers developed the best (60%).
Yet more recent research published Wednesday revealed a third COVID-19 vaccine dose not only was safe among transplant patients, but also effective.
Among 120 transplant recipients, those who got a third shot of the Moderna vaccine had an antibody response rate of 55% compared to just 18% among those who got a placebo. The booster shot also helped patients develop “robust” T-cell responses, which are other parts of the immune system that help prevent severe illness.
“This is an important win for our patients because the results are quite conclusive,” joint-senior author of the clinical trial Dr. Atul Humar, medical director of the Ajmera Transplant Centre at the University Health Network in Canada, said in a statement. “The third dose was safe and well tolerated and should lead to a change in practice of giving third doses to this vulnerable population.”
Do healthy people need booster COVID-19 shots?
Vaccine developers have made their own announcements saying healthy people will eventually need a third dose to bolster immunity, but federal health officials have held back from recommending booster shots because of a lack of data.
As more dangerous variants spread, however, scientists are admitting what will soon become reality.
“Inevitably, there will be a time when we’ll have to give boosts. What we’re doing, literally, on a weekly and monthly basis is following cohorts of patients to determine if, when and whom should get it,” Dr. Anthony Fauci, White House chief medical adviser, told NBC’s “TODAY” on Thursday. “But right now at this moment, other than the immunocompromised, we’re not going to be giving boosters to people, but we will be following them very carefully and if they do need it, we’ll be ready to give it to them.”
Data show the vaccines still offer adequate protection against the coronavirus and its variants by preventing hospitalization and death and most infections. Health officials say it’s still possible to get infected after vaccination, but odds are much lower.
A recent study of hundreds of Kentucky residents found that unvaccinated people were more than twice as likely to contract COVID-19 again than people who were fully vaccinated.
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