The Group Health Research Institute, Group Health, Seattle, Washington, USA.
J Infect Dis. 2011 Sep 15;204(6):854-63. doi: 10.1093/infdis/jir440.
Although pregnant women are at increased risk of severe illness following influenza infection, there is relatively little information on the immunogenicity of influenza vaccines administered during pregnancy.
We conducted a clinical trial that enrolled 120 pregnant women in which participants were randomly assigned to receive an inactivated 2009 H1N1 influenza vaccine containing either 25 μg or 49 μg of hemagglutinin (HA) in a 2-dose series with a 21-day period between administration of the first and second doses.
Following the first vaccination, HA inhibition (HAI) titers of ≥1:40 were detected in 93% (95% confidence interval [CI], 82%-98%) of subjects who received the 25-μg dose and 97% (95% CI, 88%-100%) of subjects receiving the 49-μg dose. In cord blood samples, HAI titers of ≥1:40 were found in 87% (95% CI, 73%-96%) of samples from the 25-μg dose group and in 89% (95% CI, 76%-96%) from the 49-μg dose group. Microneutralization titers tended to be higher than HAI titers, but the patterns of response were similar.
In pregnant women, 1 dose of an inactivated 2009 H1N1 influenza vaccine containing 25 μg of HA elicited an antibody response typically associated with protection against influenza infection. Efficient transplacental transfer of antibody was also documented.
尽管孕妇在流感感染后患重病的风险增加，但关于在怀孕期间接种流感疫苗的免疫原性的信息相对较少。
我们进行了一项临床试验，该试验纳入了 120 名孕妇，参与者被随机分配接受两剂含 25μg 或 49μg 血凝素（HA）的 2009 年 H1N1 流感灭活疫苗，两剂之间间隔 21 天。
首次接种后，接受 25μg 剂量的 93%（95%置信区间[CI]，82%-98%）和接受 49μg 剂量的 97%（95%CI，88%-100%）的受试者中均有 93%（95%CI，82%-98%）检测到抗血凝素抑制（HAI）滴度≥1:40。在脐带血样本中，接受 25μg 剂量的 87%（95%CI，73%-96%）和接受 49μg 剂量的 89%（95%CI，76%-96%）的样本中均发现 HAI 滴度≥1:40。微量中和滴度往往高于 HAI 滴度，但反应模式相似。
在孕妇中，一剂含 25μg HA 的 2009 年 H1N1 流感灭活疫苗可引发通常与预防流感感染相关的抗体反应。也有证据表明抗体高效地通过胎盘转移。
