英国 2016-2017 年和 2017-2018 年流感季节中，活减流感疫苗受种者的病毒脱落情况。
Viral Shedding in Recipients of Live Attenuated Influenza Vaccine in the 2016-2017 and 2017-2018 Influenza Seasons in the United Kingdom.
机构信息
Virus Reference Department, National Infection Service, Public Health England, Colindale, United Kingdom.
Statistics, Modelling and Economics Department, National Infection Service, Public Health England, Colindale, United Kingdom.
出版信息
Clin Infect Dis. 2020 Jun 10;70(12):2505-2513. doi: 10.1093/cid/ciz719.
BACKGROUND
The (H1N1)pdm09 live attenuated influenza vaccine (LAIV) strain was changed for the 2017-2018 influenza season to improve viral fitness, following poor protection against (H1N1)pdm09 viruses in 2015-2016. We conducted LAIV virus shedding studies to assess the effect of this change.
METHODS
Children aged 2-18 years were recruited to receive LAIV in the 2016-2017 (n = 641) and 2017-2018 (n = 362) influenza seasons. Viruses from nasal swabs taken 1, 3, and 6 days postvaccination were quantified by reverse-transcription polymerase chain reaction and area under the curve titers were determined. Presence and quantity of shedding were compared between strains and seasons with adjustment for age and prior LAIV (n = 436), inactivated seasonal vaccine (n = 100), or (H1N1)pdm09 vaccine (n = 166) receipt.
RESULTS
(H1N1)pdm09 detection (positivity) in 2016-2017 and 2017-2018 (11.2% and 3.9%, respectively) was lower than that of H3N2 (19.7% and 18.7%, respectively) and B/Victoria (28.9% and 33.9%, respectively). (H1N1)pdm09 positivity was higher in 2016-2017 than 2017-2018 (P = .005), but within shedding-positive participants, the (H1N1)pdm09 titer increased in 2017-2018 (P = .02). H3N2 and influenza B titers were similar between seasons. Positivity declined with age, and prior vaccination reduced the likelihood of shedding influenza B but not (H1N1)pdm09.
CONCLUSIONS
The (H1N1)pdm09 titer increased in 2017-2018, indicating more efficient virus replication in shedding-positive children than the 2016-2017 strain, although overall positivity was reduced. Age and vaccination history require consideration when correlating virus shedding and protection.
CLINICAL TRIALS REGISTRATION
NCT02143882, NCT02866942, and NCT03104790.
背景
为提高病毒适应性，2017-2018 流感季对（H1N1）pdm09 活减毒流感疫苗（LAIV）株进行了更改，此前该疫苗在 2015-2016 年对（H1N1）pdm09 病毒的保护效果不佳。我们开展了 LAIV 病毒脱落研究，以评估这一变化的影响。
方法
2016-2017 年（n=641）和 2017-2018 年（n=362）流感季招募年龄为 2-18 岁的儿童接种 LAIV。接种后第 1、3 和 6 天，通过逆转录聚合酶链反应定量鼻拭子中的病毒，并确定曲线下面积滴度。对两季的毒株进行了比较，共纳入了 436 例有、无 LAIV（n=436）、季节性灭活疫苗（n=100）或（H1N1）pdm09 疫苗（n=166）接种史的儿童。调整年龄和既往 LAIV、季节性灭活疫苗或（H1N1）pdm09 疫苗接种史（n=436），评估病毒脱落的阳性率和病毒载量。
结果
2016-2017 年和 2017-2018 年（分别为 11.2%和 3.9%）（H1N1）pdm09 的检测阳性率均低于 H3N2（分别为 19.7%和 18.7%）和 B/Victoria（分别为 28.9%和 33.9%）。（H1N1）pdm09 的阳性率在 2016-2017 年高于 2017-2018 年（P=0.005），但在脱落阳性的参与者中，（H1N1）pdm09 的滴度在 2017-2018 年升高（P=0.02）。H3N2 和 B 型流感病毒的滴度在两季间无显著差异。阳性率随年龄下降，既往接种可降低 B 型流感病毒的脱落率，但不影响（H1N1）pdm09。
结论
尽管（H1N1）pdm09 的总体阳性率下降，但 2017-2018 年（H1N1）pdm09 的滴度升高，提示在脱落阳性的儿童中，病毒复制更有效，这表明 2017-2018 年的毒株比 2016-2017 年的更有效。年龄和接种史是与病毒脱落和保护相关时需要考虑的因素。
临床试验注册
NCT02143882、NCT02866942 和 NCT03104790。
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