Preventing flu in kidney transplant patients

The first trial of the influenza vaccine, Fluad, in kidney transplant recipients shows that this vaccine is safe and at least as immunogenic as the standard flu shot, Agriflu. Fluad contains an adjuvant that boosts the immune response and is normally approved only for people over 65. Agriflu is non-adjuvanted and authorized for anyone over six months. In the clinical trial, Fluad was found to be more effective in kidney transplant patients under the age of 65.

While most people recover quickly from influenza, a common flu can cause serious complications in organ transplant receivers, including death. Vaccination is recommended for these patients, but their response to vaccines is suboptimal and there have been cases of transplant rejection after vaccinating against the 2009 swine flu.

A research team comprised of members from Canada, the UK and Saudi Arabia administered either Fluad or Agriflu to 60 kidney transplant recipients and compared their responses.

Following the patients over six months after injection, the researchers found that both vaccines were well tolerated, with only minor side-effects. Then, they analyzed seroconversion: the development of enough antibodies against influenza. Among the 31 people who received Fluad, 71% demonstrated seroconversion to at least one of the three influenza antigens contained in the vaccines. Agriflu, on the other hand, was effective in 55.2% of the other group.

Although this difference was not statistically significant, when the research team looked at the age difference, they found that the seroconversion rate of patients between 18 and 64 was significantly greater with Fluad (84.6%) than Agriflu (58.3%). “Although the vaccine is licensed for use in people over 65, this study shows that it could be a better option in organ transplant recipients who are 65 or younger,” explains Mona Al-Dabbagh from Saudi Arabia’s King Abdulaziz Medical City.

The team also checked if patients produced antibodies against the transplanted organ, which could lead to rejection. “Although some doctors suggest transplant patients should not be vaccinated because of the risk of rejection, this study found that there was not a significant increase in antibodies against the transplanted organ after vaccination,” explains Al-Dabbagh.

“The next challenge is to understand if it is safe to administer Fluad early after the transplant, and to develop an effective vaccine for transplant recipients over 65,” says Al-Dabbagh. 

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