The researchers found that patients whose kidneys had failed were about five times more likely to develop antibodies than those who had just received a new organ.
The team, from Rouen University Hospital in France, says that the results indicate the need to conduct more research on different vaccination strategies for transplant patients, so that they obtain the greatest possible protection against “Covid-19”.
Recent studies have indicated that people who have undergone organ transplants are less protected than the general population.
A study by Johns Hopkins University in March 2021 found that only 17% of transplant recipients produced acceptable levels of antibodies after just one dose of the two-dose “Covid-19” vaccine.
A follow-up in May found that after the second dose, that number rose to just 54 percent. The reason for this low level of protection is that people who receive transplants use lifelong immunosuppressants to prevent their bodies from rejecting the donated organ.
In the new study, published in the Journal of the American Society of Nephrology, the team looked at a total of 55 patients: 45 kidney transplant recipients and 10 patients undergoing chronic dialysis.
All patients received two doses of the “Pfizer-Bioantek” vaccine.
After the second dose, 88.9% of the dialysis patients developed neutralizing antibodies to the virus – in line with the numbers observed in the general population.
In comparison, responses were seen in 17.8 percent of transplant recipients, representing a 4.9-fold decrease.
In addition, when the researchers looked at the T-cell response, they found that it was evident in 100% of patients undergoing dialysis, but only 57.8% of transplant patients.
The team says the findings may be used to develop specific vaccination strategies for kidney transplant recipients.
“The vaccine appears to be effective in individuals undergoing dialysis, which indicates that vaccination should be strongly recommended in these patients,” study author Dr. Dominique Bertrand said in a statement.
In contrast, the low antibody response observed in kidney transplant recipients is worrisome. However, antibodies are not the full spectrum of vaccine-induced protection. T-cell immunity is also likely to be very important.