People with weakened immune systems are also more likely to have a serious bout of COVID-19.
The risk of a vaccinated transplant patient getting a breakthrough infection is 82-times higher than the general population's and their risk of hospitalization or death is 485-times greater, according to a recent study.
"The take-home message is that vaccine protection is much lower in transplant patients," said Dr. Dorry Segev, a transplant surgeon at Johns Hopkins Medicine who led the recent research.
Dr. Anthony Fauci told USA TODAY's Editorial Board last week that he thought the rules should be changed for the immunocompromised, allowing them to get an additional vaccine dose.
"Some mechanism needs to be done quickly to get those people protected,” said Fauci, a presidential adviser and director of the National Institute of Allergy and Infectious Diseases.
He and other officials have said booster doses are not needed yet by the general public. Although protection is expected to begin waning between 6-12 months, the vaccines still seem to be working well in preventing serious disease and the vast majority of hospitalized patients are unvaccinated.