Two doses of pandemic influenza A needed for pediatric liver transplant patients

Haller W. Liver Transpl. 2011;doi:10.1002/lt.22283.

Two doses of pandemic influenza A vaccine are needed to receive a reliable immune response in adolescent pediatric liver transplant patients, according to a study.

Conducted between November 2009 and October 2010, the study focused on 21 liver transplant patients who were at least 10 years of age and were part of the Children’s Hospital Melbourne liver transplant program. A venous blood sample was taken from each participant pre-vaccination at the liver transplant outpatient clinic. A single 15-mcg intramuscular injection of pH1N1/09 vaccine was administered to each patient, and another blood sample was taken at a median of 10 weeks after the vaccination.

At baseline, 33.4% of patients were already seropositive, and the seroconversion rate was 62% after first dose. Adolescents in the study who were seronegative were given a second dosage of the vaccine. After the second dosage, 67% of patients were seropositive.

“Patients with successful seroconversion displayed no difference with regards to age, gender, immunosuppressive regimen, calcineurin inhibitor levels or lymphocyte count and time between vaccination and post-vaccination blood sampling when compared with the non-converting group of patients,” researchers wrote.

They also said there was a smaller chance of successful immune response to the vaccine in patients who underwent transplantation more recently.

Disclosure: The researchers report no relevant financial disclosures.

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