DENVER—The H1N1 flu vaccine Pandemrix is insufficient in helping protect most transplant patients, according to a study presented Nov. 19 at the American Society of Nephrology’s annual meeting.
During the recent H1N1 pandemic, officials urged vaccination especially for immunocompromised individuals such as those with HIV/AIDS or patients taking immunosuppressive drugs.
Between 80 percent and 95 percent of healthy adults develop a sufficient immune response after a single H1N1 vaccination, but what about immunosuppressed patients?
Susanne Brakemeier (Charite, Berlin, Germany) and colleagues studied the immune responses to the H1N1 vaccine (Pandemrix) in 60 patients (12 female/48 male) taking immunosuppressives and at least six months post transplant. Twenty-two healthy individuals served as controls. Two transplant patients had immune responses to the vaccine before being immunized.
Of the remaining 58 patients, only 34.5 percent mounted a sufficient immune response to protect against the virus, compared with 91 percent in the control group. And 65.5 percent of transplant patients exhibited no response or a weak response. A subgroup of transplant patients received a booster vaccination; 42 percent mounted a sufficient immune response.
“These data suggest that in renal transplant patients, a single dose of Pandemrix as well as booster vaccination is not sufficient to induce a protective immune response,” the authors concluded.
Brakemeier advocated for studying H1N1 vaccine response rates in transplant patients more thoroughly. In addition, some patients mounted immune responses against their donated organ after being vaccinated, which highlights the need to test the safety of new vaccines in transplant patients.
