The Food and Drug Administration on Thursday approved the third dose of Pfizer-BioNTech and Moderna’s coronavirus vaccines for some people with compromised immune systems, giving doctors more leeway to protect those who have failed to respond adequately to an initial series of vaccinations .
The approval, in the form of updates to the existing emergency approvals, for the two vaccines is for people who have received solid organ transplants and others with similarly compromised immune systems, the FDA said.
The agency’s decision came a day before the Centers for Disease Control and Prevention’s independent advisory committee was due to review and vote on whether to recommend the move. The committee will likely give its approval, and the CDC would follow suit with its own approval of the additional doses.
“The FDA is particularly aware that immunocompromised people are at particular risk for serious illness,” said Dr. Janet Woodcock, acting FDA commissioner, in a statement. “After a thorough review of the available data, the FDA determined that this small, vulnerable group could benefit from a third dose of the Pfizer BioNTech or Moderna vaccines.”
The approval of the third dose marks a busy next stage for federal vaccine authorities – and a new phase in the country’s vaccination campaign. The agency is expected to approve Pfizer-BioNTech’s vaccine by early next month. This will most likely trigger a wave of vaccination requests from companies and organizations that have waited to be vaccinated until the FDA has fully cleared a vaccine.
At the same time, government scientists and regulators are wrestling over whether more Americans will need booster vaccinations, a hotly debated move that many scientists argue is not yet backed by data. Other countries like Israel and Germany have implemented booster policies.
“Other people who are fully vaccinated are adequately protected and do not currently need an additional dose of the Covid-19 vaccine,” said Dr. Woodcock in her statement on Thursday, adding that the agency is “actively engaged in a science-based, rigorous process with our federal partners to consider whether an additional dose will be needed in the future.”
The United States is the youngest country to start offering a third dose to people with weaker immune systems. France has been offering extra doses of vaccine to certain people with weak immune responses since April, and Germany and Hungary have recently followed suit.
About 3 percent of Americans have weakened immune systems for a variety of reasons, from a history of cancer to taking certain medications, such as steroids.
The FDA’s decision to limit the category of immunocompromised individuals to receive the additional dose was awaited. Many scientists argue that the immunocompromised population is too diverse to consistently recommend additional shots of the coronavirus vaccine. Some can be protected by the standard vaccine dosage despite their conditions. Others may be poorly shielded by the vaccines but may not benefit from additional vaccination.
Studies suggest that patients such as organ transplant recipients are in between – often showing a poor immune response to the standard vaccination schedule but benefiting from a third vaccination. A recent randomized, placebo-controlled study by Canadian researchers found that a third dose of the Moderna vaccine improved the immune response of the people in this group.