As the Delta variant wreaks havoc across the U.S, we’re hearing more and more about people testing positive for COVID despite being fully vaccinated. These breakthrough infections are expected and can happen to anyone, according to the Centers for Disease Control and Prevention (CDC). Las Vegas tourists, wedding guests, and even White House officials have all been hit with breakthrough infections over the last month. But the risk isn’t the same across the board: New research has found that some people do have a dramatically higher risk of getting COVID after vaccination.
A study published July 23 in the Transplantation journal looked at COVID infections among transplant recipients. The researches analyzed data from more than 18,000 fully vaccinated people who had transplants for large organs from 17 transplant centers across the U.S. There were 151 breakthrough infections among the patients studied. According to the researchers, the risk of getting COVID after vaccination is 82 times higher for people who have had a transplant.
Out of the transplant breakthrough infections, 87 people were also hospitalized and 14 died. According to the study, this translates to a 485 times higher risk of breakthrough infection with associated hospitalization and death for transplant recipients. Per the CDC, most people who get breakthrough infections should not expect severe complications.
Study co-author Dorry Segev, MD, a transplant surgeon with Johns Hopkins University, told Science magazine that this is the first study to provide clinical evidence across multiple hospitals that transplant recipients are less protected by the vaccine.
“This is a stark clinical reminder that transplant patients are inadequately protected by the standard vaccine series,” Segev said. He added that transplant patients should still get their COVID vaccine as a little bit of protection is better than none, but should also continue to wear masks and practice social distancing.
The increased risk of breakthrough infections among this group may be because immunosuppressant drugs, which are commonly used to keep the body from rejecting a new organ, affect the immune response in those who take them. Another study published May 5 in JAMA looked at 472 transplant recipients who took antimetabolites, an immunosuppressant medication, and found that 57 percent produced no antibody response after either dose of a mRNA vaccine.
And while third doses haven’t yet been officially recommended in the U.S. for immunosuppressed individuals, they have shown some promise. A June 23 study published in The New England Journal of Medicine found that 68 percent of organ recipients produced antibodies after a third dose of the Pfizer vaccine. Another study published July 23 in JAMA found that a third dose of Moderna’s vaccine kickstarted antibodies for 49 percent of kidney transplant patients who had generated little to no antibodies after two doses.
On July 22, the CDC’s Advisory Committee on Immunization Practices (ACIP) met to discuss whether or not immunocompromised people need a third shot, concluding that “emerging data suggest that an additional COVID-19 vaccine dose in immunocompromised people enhances antibody response and increases the proportion who respond.” But the CDC has yet to formally recommend this practice.