National Institute of Respiratory Diseases "Ismael Cosio Villegas" (INER), Department of Research in Virology and Mycology, Mexico City, Mexico; National Autonomous University of Mexico, Postgraduate in Biological Sciences, Faculty of Medicine, Mexico City, Mexico.
National Institute of Respiratory Diseases "Ismael Cosio Villegas" (INER), Research in Clinical Epidemiology, Mexico City, Mexico.
Int J Infect Dis. 2022 Dec;125:114-119. doi: 10.1016/j.ijid.2022.10.029. Epub 2022 Oct 22.
We evaluated the VE and the mutations of the viruses present in the Mexican population at the beginning of 2018.
We diagnosed influenza in outpatients with a high-performance Rapid Influenza Diagnostic Test (RIDT) qRT-PCR. Descriptive statistics were used to describe the study population, while the chi-square test was used to determine clinical variables. VE was analyzed through a negative test design. We sequenced the hemagglutinin (HA) gene, performed a phylogenetic analysis, and analyzed the nonsynonymous substitutions both in and outside antigenic sites.
Of the 240 patients analyzed, 42.5% received the trivalent vaccine, and 37.5% were positive for influenza. The VE for the general population for any influenza virus type or subtype was 37.0%, while the VE for the predominant influenza A(H3N2) subtype was the lowest (19.7%). The phylogenetic analysis of HA showed the co-circulation of clades and subclades 3C.2a1, 3C.2a1b, 3C.2a2, 3C.2a2re, 3C.2a3, and 3C.3a with identities approximately 97-98% similar to the vaccine composition.
Low VE was related to the co-circulation of multiple clades and subclades of influenza A(H3N2), with sufficient genetic and phenotypic distance to allow for the infection of vaccinated individuals.
我们评估了 2018 年初墨西哥人群中病毒的 VE 和突变情况。
我们使用高性能快速流感诊断测试（RIDT）qRT-PCR 对门诊患者进行流感诊断。使用描述性统计来描述研究人群，而卡方检验用于确定临床变量。通过阴性测试设计分析 VE。我们对血凝素（HA）基因进行测序，进行系统发育分析，并分析抗原位点内外的非同义替换。
在分析的 240 名患者中，42.5%接种了三价疫苗，37.5%流感检测呈阳性。普通人群对任何流感病毒类型或亚型的 VE 为 37.0%，而主要的 A(H3N2)亚型的 VE 最低（19.7%）。HA 的系统发育分析显示，3C.2a1、3C.2a1b、3C.2a2、3C.2a2re、3C.2a3 和 3C.3a 分支和亚分支的共同循环，其身份与疫苗组成的相似度约为 97-98%。
低 VE 与 A(H3N2)流感的多个分支和亚分支的共同循环有关，具有足够的遗传和表型距离，允许接种个体感染。
