Department of Family Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Department of Family Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Vaccine. 2020 Jul 14;38(33):5171-5177. doi: 10.1016/j.vaccine.2020.06.023. Epub 2020 Jun 21.
Current influenza vaccine effectiveness (VE) improvement efforts focus on minimizing egg adaptation mutations during manufacture. This study compared immune response of two FDA-approved quadrivalent inactivated influenza vaccines in an unblinded randomized controlled trial.
Participants were 144 community dwelling, healthy children/adolescents aged 4-20 years, randomized 1:1 in blocks of 4 to a vaccine grown in cell culture (ccIIV4 [Flucelvax®]; n = 85); or in egg medium (IIV4 [Fluzone ®]; n = 83). Blood was drawn at day 0 prevaccination and at day 28 (19-35 days) post vaccination. Hemagglutination inhibition (HI) assays against A/H1N1 and both B strains and microneutralization (MN) assays against egg-based and cell-based A/H3N2 strains were conducted. The primary outcome measure was seroconversion (day 28/day 0 titer ratio ≥ 4 with day 28 titer ≥ 40). Secondary outcomes were elevated titers (day 28 HI titer ≥ 1:110), geometric mean titers (GMTs) and mean fold rise (MFR) in titers. Outcomes were compared for 74 ccIIV4 recipients and 70 IIV4 recipients, and for those vaccinated and unvaccinated the previous year. Only the HI and MN laboratory analysis team was blinded to group assignment.
In this racially diverse (81% non-white) group of children with a median age of 14 years, baseline demographics did not differ between vaccine groups. At day 0, half or more in each vaccine group had elevated HI or MN titers. Low seroconversion rates (14%-35%) were found; they did not differ between groups. Among 2018-19 ccIIV4 recipients, those unvaccinated in the previous season showed significantly higher MFR against A/H1N1 and A/H3N2 cell-grown virus than the previously vaccinated. Similar results were found for MFR against B/Victoria among 2018-2019 IIV4 recipients.
In mostly older children with high baseline titers, no differences in seroconversion or other measures of antibody titers were found between ccIIV4 and IIV4 recipients against egg- and cell-grown influenza vaccine viruses.
NCT03614975.
目前流感疫苗效果（VE）的改进工作侧重于在生产过程中尽量减少鸡蛋适应突变。本研究在一项非盲随机对照试验中比较了两种经美国食品和药物管理局批准的四价灭活流感疫苗的免疫反应。
参与者为 144 名居住在社区的健康儿童/青少年，年龄 4-20 岁，按 4 人为一组进行 1:1 随机分组，分别接种细胞培养疫苗（ccIIV4 [Flucelvax®]；n=85）或鸡胚中培养的疫苗（IIV4 [Fluzone®]；n=83）。在接种前 0 天和接种后 28 天（19-35 天）采血。使用血凝抑制（HI）试验检测针对 A/H1N1 和两种 B 株的抗体，使用微量中和（MN）试验检测针对基于鸡胚和细胞的 A/H3N2 株的抗体。主要观察指标为血清转化（第 28 天/第 0 天滴度比值≥4，第 28 天滴度≥40）。次要观察指标为升高的滴度（第 28 天 HI 滴度≥1:110）、几何平均滴度（GMT）和滴度平均倍数升高（MFR）。对 74 名 ccIIV4 接种者和 70 名 IIV4 接种者进行了比较，并对前一年接种和未接种疫苗的人群进行了比较。只有 HI 和 MN 实验室分析小组对分组情况不知情。
在这个种族多样化（81%为非白人）的儿童群体中，中位年龄为 14 岁，疫苗组之间的基线人口统计学特征没有差异。在第 0 天，每组中有一半或更多的人 HI 或 MN 滴度升高。发现血清转化率较低（14%-35%）；两组之间没有差异。在 2018-19 年 ccIIV4 接种者中，与前一年接种疫苗者相比，未接种疫苗者对 A/H1N1 和 A/H3N2 细胞培养病毒的 MFR 显著升高。在 2018-2019 年 IIV4 接种者中，也发现了对 B/Victoria 株 MFR 的类似结果。
在基线滴度较高的大多数年龄较大的儿童中，ccIIV4 和 IIV4 接种者对鸡胚和细胞培养的流感疫苗病毒的血清转化率或其他抗体滴度指标没有差异。
NCT03614975。
