长期以来,抑制血凝的抗体一直被认为是预防流感的相关因素,但这些抗体只是潜在保护性抗体的一部分.中和和神经氨酸酶抗体也可能有助于保护,但是关于他们与保护的关联的数据是有限的。
我们测量了在训练期间经历H3N2流感爆发的未接种疫苗的军事新兵的爆发前血凝素假病毒中和(PVN)和神经氨酸酶抑制(NAI)抗体滴度。我们进行了一项病例对照研究,以使用逻辑回归分析研究滴度与针对流感疾病或H3N2相关性肺炎的保护之间的关系。
随着PVN滴度每增加2倍,经医学治疗的聚合酶链反应确认的H3N2感染(H3N2)的几率降低了41%(比值比[OR],0.59;95%置信区间[CI],.45至.77;P<.001)。在H3N2+中,患肺炎的几率降低了52%(或,0.48;CI,.25至.91;P=.0249)。随着NAI滴度每增加2倍,接受医学治疗的H3N2感染的几率降低了32%(OR,0.68;95%CI,.53至.87;P=.0028),但NAI滴度与H3N2相关性肺炎之间无相关性.PVN和NAI抗体也没有协同作用。
PVN和NAI滴度与流感患病风险降低独立相关。与保护相关的NAI滴度对漂移菌株的反应性宽度大于PVN滴度。这些发现表明PVN和NAI滴度是评估流感感染几率的有价值的生物标志物。
Antibodies that inhibit hemagglutination have long been considered a correlate of protection against influenza, but these antibodies are only a subset of potentially protective antibodies. Neutralizing and neuraminidase antibodies may also contribute to protection, but data on their associations with protection are limited.
We measured preoutbreak hemagglutinin pseudovirus neutralization (PVN) and neuraminidase inhibition (NAI) antibody titers in unvaccinated military recruits who experienced an H3N2 influenza outbreak during training. We conducted a case-control study to investigate the association between titers and protection against influenza illness or H3N2-associated pneumonia using logistic regression.
With every 2-fold increase in PVN titer, the odds of medically attended polymerase chain reaction-confirmed H3N2 infection (H3N2+) decreased by 41% (odds ratio [OR], 0.59; 95% confidence interval [CI], .45 to .77; P < .001). Among those who were H3N2+, the odds for pneumonia decreased by 52% (OR, 0.48; CI, .25 to .91; P = .0249). With every 2-fold increase in NAI titer, the odds of medically attended H3N2 infection decreased by 32% (OR, 0.68; 95% CI, .53 to .87; P = .0028), but there was no association between NAI titers and H3N2-associated pneumonia. There was also no synergistic effect of PVN and NAI antibodies.
PVN and NAI titers were independently associated with reduced risk of influenza illness. NAI titers associated with protection had greater breadth of reactivity to drifted strains than PVN titers. These findings show that PVN and NAI titers are valuable biomarkers for assessing the odds of influenza infection.