Both the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention's (CDC) independent vaccine advisory panel have approved booster shots for Americans with weakened immune systems, setting the stage for the CDC to overall authorize the shots to protect those more vulnerable from the highly contagious Delta variant.
On Thursday, the FDA had authorized third COVID booster shots of either vaccines developed by Moderna (NASDAQ: MRNA) or Pfizer (NYSE: PFE)-BioNTech (NASDAQ: BNTX) for people who are immunocompromised, which include organ transplant recipients and those with cancer.
"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," said FDA Commissioner Dr. Janet Woodcock in a press statement. "Today's action allows doctors to boost immunity in certain immunocompromised individuals who need extra protection...other individuals who are fully vaccinated are adequately protected and do not need an additional dose of COVID-19 vaccine at this time."
Following the FDA's approval, the CDC's Advisory Committee on Immunization Practices unanimously voted Friday to also recommended booster shots of Pfizer's or Moderna's vaccines to more vulnerable Americans. Now, the CDC needs to accept the panel's recommendation, which is expected later Friday. After the CDC's final decision, booster doses could start being administered to patients immediately.
Neither agency approved second doses of Johnson & Johnson's (NYSE: JNJ) vaccine to act as an immune system booster.
The CDC recommended a third dose 28 days or more after more vulnerable individuals complete the initial two dose regimens of either vaccine. The extra doses were recommended for Pfizer recipients who are 12 or older and Moderna recipients aged 18 years or older. The group said that plan to revisit this decision for younger Moderna recipients after the FDA clears the vaccine for adolescents.
Immunocompromised patients represent about 2.7% of the U.S. adult population and 44% of hospitalized breakthrough infections among the fully vaccinated, CNBC reports. Five small studies cited in the CDC's decision showed that 11% to 80% of people with weakened immune systems do not have detectable antibodies against COVID-19 after two dose of vaccine.
Moreover, among those who had no detectable antibody response following full vaccination, 33% to 50% developed an antibody response after a third dose, according to the CDC.
The federal health agencies' decision comes soon after the World Health Organization (WHO) pleaded with wealthy nations to pause distribution of third booster shots through September in order to aid the global health agency's initiative to vaccinate 10% of every nation's population by October. However, the WHO noted that they were not referring to extra doses for more vulnerable individuals, meaning those with weakened immune systems.