The Centers for Disease Control and Prevention’s (CDC) advisory committee has recommended that immunocompromised Americans receive a third COVID-19 vaccine dose.
On Friday, the Advisory Committee on Immunization Practices (ACIP) voted unanimously that certain patients with weakened immune systems can get a booster shot of the Pfizer-BioNTech or Moderna vaccines.
It comes one day after the U.S. Food and Drug Administration (FDA) expanded the emergency use authorizations to allow the shots to be administered as boosters.
Until the FDA announced its decision, ACIP was unable to recommend third doses, a necessary step before pharmacists or clinicians can immunize patients.
As many as three percent of all Americans are considered immunocompromised due to cancer treatment, autoimmune diseases, HIV or other ailments.
In the past few months, several studies have suggested that immunocompromised people don’t have as much protection after being fully vaccinated as healthy people.
The CDC’s Advisory Committee on Immunization Practices voted unanimously on Friday to recommend third doses for immunocompromised Americans. Pictured: CDC headquarters in Atlanta, Georgia
Past studies have found that, even after being fully vaccinated, people with weakened immune systems have low or undetectable antibody levels. Pictured: A California State University Long Beach student receives a first dose of the Pfizer COVID-19 vaccine, August 11
Previously, health experts had said that there was no evidence to suggest that fully vaccinated Americans needed booster shots.
However, more and more research has shown that people with weakened immune systems have low or undetectable antibody levels, even after two doses.
A study in May found that all cancer patients developed fewer antibodies after being vaccinated compared to healthy participants and 10 percent barely developed antibodies at all.
Another study in June looked at 30 organ transplant recipients and found that 24 developed negative antibody levels – meaning they did not have any immune-fighting cells – after two doses of the Pfizer-BioNTech or Moderna vaccines.
The findings are worrying because immunocompromised people are already at an increased risk of hospitalization or death from the virus.
This makes COVID-19 immunity even more crucial for this population.
However, third doses may be a way to boost antibody levels.
For example, the study about organ transplant patients found that one-third of patients with negative antibody levels from the first two doses now showed an increase after a third dose.
CDC director Dr Rochelle Walensky signed off on the recommendation on Friday afternoon, which is required before patients can be given extra doses.
In a statement, she said studies had found fully vaccinated immunocompromised people have accounted for a large proportion of between 40 and 44 percent of hospitalized breakthrough cases.
Additionally, those who become infected can transmit the virus to household contacts.
‘At a time when the Delta variant is surging, an additional vaccine dose for some people with weakened immune systems could help prevent serious and possibly life-threatening COVID-19 cases within this population,’ Walensky wrote.
Under ACIP’s recommendation, only immunocompromised patients who received the Pfizer or Moderna vaccines would be allowed to receive a booster.
The committee said that patients who get a third dose make sure it matches the previous two doses, meaning patients who received two doses of Moderna get a third dose of Moderna and those given two Pfizer shots get a third shot from Pfizer.
Americans who received the one-shot Johnson & Johnson vaccine were not included in this decision.
ACIP said there is not enough evidence to suggest that immunocompromised adults who received J&J need an extra dose.
The lack of approval until this week did not deter some Americans from taking initiative and receiving third shots.
An internal CDC document obtained by ABC News estimates that 1.1 million Americans who have received the Moderna or Pfizet vaccine have gotten another shot.
Third doses are currently approved in several countries including Chile, France, Germany and Israel.