FDA Approves COVID Vaccine Booster Shots for Immunocompromised

In a much anticipated and pretty much expected move, the Food and Drug Administration (FDA) yesterday recommended that COVID-19 booster shots be given to people with compromised immune systems.

In a press release, Acting FDA Commissioner Janet Woodcock, MD, said that yesterday’s ruling “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. The FDA is actively engaged in a science-based, rigorous process with our federal partners to consider whether an additional dose may be needed in the future.”

The FDA expanded the emergency use authorization (EUA) for both the Pfizer/BioNTech and Moderna vaccines. That decision will now be evaluated by the CDC’s Advisory Committee on Immunization Practices (ACIP) this afternoon. That’s expected to be a formality as the committee in July urged the FDA to authorize a third dose of the vaccine for the immunocompromised. The booster shots could become available for immunocompromised adults as soon as tonight.

The ruling was primarily made to benefit organ transplant patients but others with compromised immune systems, such as those battling cancer and HIV, would also be eligible for booster shots. About 2.7% of adults in the United States are immunocompromised, according to the CDC. However, recent ACIP data show that the immunocompromised make up about 44% of COVID-19 breakthrough cases.

The FDA encourages such patients to explore treatment options with their health care providers should they contract COVID-19 or be exposed to someone with COVID-19.

In the FDA press release, Woodcock noted that “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”

Both the Pfizer/BioNTech and Moderna vaccines were approved under the FDA’s emergency use authorization (EUA). The former for people aged 12 and up, the latter for those 18 and older. Both are administered in 2 doses. The Pfizer/BioNTech doses are 3 weeks apart; the Moderna doses are a month apart.

In the press release, the FDA states that “the authorizations for these vaccines have been amended to allow for an additional, or third, dose to be administered at least 28 days following the two-dose regimen of the same vaccine to individuals 18 years of age or older (ages 12 or older for Pfizer-BioNTech) who have undergone solid organ transplantation, or who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise.”

The disussion about the availability of COVID-19 booster shots—who should be eligible and who shouldn't—might not end with the immunocompromised. As Infection Control Today^®(ICT^®) has reported, the delta variant might force health care officials to offer the shots to Americans aged 60 and older. Other countries are moving in this direction. Israel has already begun offering booster shots to older citizens. The UK, France and Germany plan to do so starting next month.

Sharon Alroy-Preis, MD, MPH, MBA, the director of Public Health Services in Israel stated recently on Face the Nation that Israeli health officials are seeing evidence of the effectiveness of the Pfizer/BioNTech COVID-19 vaccine waning over time. Overall, it is still very effective in preventing hospitalizations and deaths, with the exception of those over 60 who have been fully vaccinated before the end of January 2021.

The Israeli data stands in contrast to data from the UK published in the New England Journal of Medicine that states that 2-dose vaccines have proven very effective against the delta variant. However, comparing the Israeli data with the UK data regarding the effectiveness of the vaccines over time might not be the way to go, according to Kevin Kavanagh, MD, a member of ICT^®’s Editorial Advisory Board.

Kavanagh notes that “the data from the United Kingdom which reports that the Pfizer mRNA vaccine is 88% effective against symptomatic infections appears to be in stark contrast to the 41% effectiveness reported by the Ministry of Health in Israel. The difference can be explained by waning of immunity over time and the vaccine dosage schedule in the two countries.”

Israel was one of the first countries to administer vaccines to their population and has a dosage schedule similar to the US. The UK, on the other hand, spaced the 2 doses apart by up to 3 months, says Kavanagh.

“Thus, most in Israel completed their vaccination schedule far ahead of those in the United Kingdom,” says Kavanagh. “Israel is currently administering boosters to those above the age of 60 and more than 5 months since vaccination. The United Kingdom is planning to start booster shots in September.”