Department of Gastroenterology and Clinical Nutrition, Melbourne, Australia.
Liver Transpl. 2011 Aug;17(8):914-20. doi: 10.1002/lt.22283.
After the announcement of a worldwide pandemic in June 2009, a single dose of a monovalent pandemic H1N1 2009 influenza A (pH1N1/09) vaccine was advocated for all Australians who were 10 years and older because of excellent immunogenicity trial results for healthy children and adults. Immunocompromised patients have previously been shown to have lower seroconversion rates after routine vaccinations. There is a lack of data concerning the immune response of this patient group after pH1N1/09 vaccination. The aim of this study was to assess the immunogenicity of a pH1N1/09 vaccine in pediatric liver transplant recipients 10 years of age or older. Liver transplant recipients ≥ 10 years were prospectively recruited. All participants were administered a single intramuscular injection of the pH1N1/09 vaccine (15 μg). Serum antibody levels were determined by hemagglutination immediately before and ≥ 6 weeks after vaccination. Clinical and laboratory data (age, time since transplantation, immunosuppression, and lymphocyte counts) were analyzed comparing seroconverters and nonconverters with the Student's t test. A second dose of the vaccine was offered to all those who displayed no seroprotective titers after the first vaccination. Antibody levels were again determined 6 weeks later. Twenty-one of 28 liver transplant patients completed the study. The seroconversion rate was 62% after the first dose and 89.5% after the second dose. At baseline, 7 of 21 patients (33.4%) were already seropositive. Increasing time since transplantation positively correlated with successful seroconversion. In conclusion, a single dose of a pandemic influenza A vaccine does not elicit a reliable immune response in adolescent pediatric liver transplant patients. A second dose of the vaccine is warranted in this group of patients, at least in a pandemic scenario. There is an urgent need to further assess vaccine strategies in this high-risk group.
2009 年 6 月宣布全球大流行后，由于健康儿童和成人的免疫原性试验结果出色，建议所有 10 岁及以上的澳大利亚人接种一剂单价大流行 H1N1 2009 流感 A 疫苗（pH1N1/09）。免疫功能低下的患者以前在常规疫苗接种后血清转化率较低。关于该人群接种 pH1N1/09 疫苗后的免疫反应，缺乏相关数据。本研究旨在评估儿科肝移植受者接种 pH1N1/09 疫苗的免疫原性。10 岁及以上的肝移植受者前瞻性入组。所有参与者均接受单剂肌内 pH1N1/09 疫苗（15μg）接种。在接种前和接种后≥6 周时通过血凝法测定血清抗体水平。通过学生 t 检验分析比较血清转化率和非转化率的临床和实验室数据（年龄、移植后时间、免疫抑制和淋巴细胞计数）。所有未显示初次接种后具有血清保护滴度的患者均接种第二剂疫苗。6 周后再次测定抗体水平。28 例肝移植患者中有 21 例完成了研究。第一剂接种后的血清转化率为 62%，第二剂接种后的血清转化率为 89.5%。在基线时，21 例患者中有 7 例（33.4%）已经呈血清阳性。移植后时间的增加与成功的血清转化率呈正相关。总之，一剂大流行流感 A 疫苗不能在青少年儿科肝移植患者中引起可靠的免疫反应。在这种情况下，该组患者至少需要在大流行期间接种第二剂疫苗。迫切需要进一步评估该高危人群的疫苗策略。
