Guiomar Raquel, Silva Susana Pereira da, Rodrigues Ana Paula, Costa Inês, Conde Patrícia, Cristóvão Paula, Pechirra Pedro, Estragadinho Paulo, Mansinho Kamal, Hungnes Olav, Graça António Silva, Nunes Baltazar
National Reference Laboratory for Influenza and Other Respiratory Viruses, Infectious Diseases Department, National Institute of Health Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal.
National School of Public Health, NOVA University, 1600-560 Lisbon, Portugal.
Vaccines (Basel). 2024 Oct 26;12(11):1218. doi: 10.3390/vaccines12111218.
BACKGROUND/OBJECTIVES: The influenza vaccination of healthcare workers (HCWs) is recommended each autumn and winter season by the relevant authorities in EU/EEA countries. The objective of this study was to evaluate the impact of repeated trivalent influenza vaccine (TIV) uptake during the 2017/2018 and 2018/2019 seasons on vaccine-derived immunity against influenza.
A cohort study of HCWs vaccinated with an annual TIV was conducted from October 2017 to June 2019. The protective antibodies against the influenza vaccine strains were assessed at three time points: prior to vaccination and at one and six months following vaccination for each season. Sera were tested by hemagglutination inhibition assay. Participants were grouped according to their history of TIV vaccination over four seasons (since 2015/16), with the groups designated as "frequently vaccinated" (≥3 vaccines) and "occasionally vaccinated" (≤2 vaccines). Seroprevalence, geometric mean titer (GMT) and seroconversion rate were compared between the frequently and occasionally vaccinated groups.
A total of 97 healthcare workers (HCWs) were enrolled in the study; 49 HCWs participated in both seasons. Thirty-two (43.2%) and forty-three (59.7%) individuals had ≥3 vaccines since 2015/2016, at recruitment and during the 2017/2018 and 2018/2019 influenza seasons, respectively. One month following vaccination, HCWs who had received occasional vaccinations demonstrated a higher prevalence of protective antibodies and a greater GMT for both influenza A(H1N1)pdm09 and A(H3N2) viruses. For influenza B Victoria, the frequently vaccinated HCWs demonstrated a higher seroprevalence rate, seroconversion, and GMT.
Previous vaccination can influence the immune response, although without substantially compromising the immunogenicity of annual influenza vaccination. HCW annual influenza vaccination is required to re-establish and maintain the antibody titers against influenza.
背景/目的：欧盟/欧洲经济区国家的相关当局建议医护人员（HCWs）在每年秋冬季节接种流感疫苗。本研究的目的是评估在2017/2018和2018/2019季节重复接种三价流感疫苗（TIV）对疫苗诱导的流感免疫力的影响。
对2017年10月至2019年6月期间每年接种TIV的医护人员进行队列研究。在三个时间点评估针对流感疫苗株的保护性抗体：每个季节接种疫苗前以及接种后1个月和6个月。通过血凝抑制试验检测血清。根据参与者在四个季节（自2015/16年以来）的TIV接种史进行分组，分为“频繁接种”（≥3剂疫苗）和“偶尔接种”（≤2剂疫苗）两组。比较频繁接种组和偶尔接种组之间的血清阳性率、几何平均滴度（GMT）和血清转化率。
共有97名医护人员纳入研究；49名医护人员参与了两个季节的研究。在招募时以及2017/2018和2018/2019流感季节，分别有32名（43.2%）和43名（59.7%）自2015/2016年以来接种了≥3剂疫苗。接种疫苗1个月后，偶尔接种的医护人员针对甲型（H1N1）pdm09流感病毒和甲型（H3N2）流感病毒的保护性抗体阳性率更高，GMT也更高。对于乙型维多利亚流感病毒，频繁接种的医护人员血清阳性率、血清转化率和GMT更高。
既往接种可影响免疫反应，尽管不会严重损害年度流感疫苗的免疫原性。医护人员每年需要接种流感疫苗以重新建立和维持针对流感的抗体滴度。
