Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
J Infect Dis. 2010 Nov 1;202(9):1327-37. doi: 10.1086/656601.
When the novel H1N1 influenza A strain appeared in April of 2009, development of novel H1N1 vaccines became a public health priority.
We conducted a phase‐2, multicenter, randomized, placebo‐controlled, observer‐blind clinical trial of a 2009 H1N1 vaccine in 1313 young (age, 18-64 years) and older (age, >or=65 years) adults. Participants were randomized 1:4:4:4 to receive 2 doses of placebo or 7.5, 15, or 30 μg of H1N1 hemagglutinin administered 21 days apart. In post hoc analyses, hemagglutination inhibition (HI) titers measured at baseline and after vaccination were analyzed for young adults (age, 18-64 years), "younger elderly" adults (age, 65-74 years), and "very elderly" adults (age, >or=75 years).
At baseline, 28.8% of young adults, 43.9% of younger elderly adults, and 62.9% of very elderly adults had HI titers to A/2009 H1N1 of >or=1:40. A single 7.5‐μg dose induced HI titers >or=1:40 in 94.5% (95% confidence interval [CI], 91.8%-96.3%) of all adults. After one 7.5‐μg dose, the geometric mean titers achieved were 326.4 (95% CI, 275.9-386.0) in young adults, 155.4 (95% CI, 123.4-195.8) in "younger elderly" adults, and 243.9 (95% CI, 167.1-356.0) in "very elderly" adults.
This large phase-2 trial demonstrated that a single 7.5‐μg dose of a monovalent unadjuvanted H1N1 vaccine induced protective HI antibody levels in adults of all ages, including very elderly adults.
Clinicaltrials.gov identifier NCT00958126.
2009 年 4 月新型 H1N1 流感病毒株出现后，研发新型 H1N1 疫苗成为公共卫生重点。
我们在 1313 名年轻（18-64 岁）和老年（年龄≥65 岁）成年人中开展了一项 2009 年 H1N1 疫苗的 2 期、多中心、随机、安慰剂对照、观察者盲法临床试验。参与者按照 1:4:4:4 的比例随机分配接受 2 剂安慰剂或 7.5、15 或 30 μg H1N1 血凝素，间隔 21 天给药。在事后分析中，分析了年轻成年人（18-64 岁）、“较年轻的老年人”（65-74 岁）和“非常老的老年人”（年龄≥75 岁）的基线和接种后的血凝抑制（HI）滴度。
基线时，28.8%的年轻成年人、43.9%的“较年轻的老年人”和 62.9%的“非常老的老年人”对 A/2009 H1N1 的 HI 滴度≥1:40。单次 7.5μg 剂量诱导的 HI 滴度≥1:40 的比例在所有成年人中为 94.5%（95%置信区间[CI]，91.8%-96.3%）。接种一剂 7.5μg 剂量后，年轻成年人的几何平均滴度为 326.4（95%CI，275.9-386.0），“较年轻的老年人”为 155.4（95%CI，123.4-195.8），“非常老的老年人”为 243.9（95%CI，167.1-356.0）。
这项大型 2 期试验表明，单次 7.5μg 剂量的单价无佐剂 H1N1 疫苗可诱导所有年龄段成年人（包括非常老的老年人）产生保护性 HI 抗体水平。
Clinicaltrials.gov 标识符 NCT00958126。
