WHO WPRO Regional Reference Measles/Rubella Laboratory and Key Laboratory of Medical Virology Ministry of Health, National Institute for Viral Disease Control and Prevention, China Center for Disease Control and Prevention, No. 155, Changbai Road, Changping District, Beijing 102206, People's Republic of China.
Shannxi Provincial Centers for Disease Control and Prevention, No. 3, Hepingwenwaijiandong Road, Xi'an 710054, People's Republic of China.
Vaccine. 2018 Sep 11;36(38):5725-5731. doi: 10.1016/j.vaccine.2018.08.028. Epub 2018 Aug 16.
To clarify the protective effect of one-dose mumps-containing vaccines (MuCV) in mainland China, the antigenic variations of HN gene and cross-neutralization capacities between MuCV and wild type genotype F MuVs were studied. In total, 70 HN gene sequences of genotype F MuV representative strains obtained from 2001 to 2015, two types of MuCV strains, 139 pairs of pre- and post-vaccination serum samples from infants receiving one dose of MuCV vaccination were analyzed. Genotype-specific amino acid variations were observed in the potential antigenic epitopes between MuCV and wild-type genotype F MuVs circulating in mainland China. The mumps neutralization antibody titers induced by one-dose MuCV were found to be generally low. Moreover, significant differences in neutralization titers were observed between vaccine and wild-type strains. It could be concluded that one-dose MuCV had a cross-protective effect against the wild-type genotype F MuVs, but its effectiveness was limited, which might be caused by insufficient doses of MuCV vaccination and the genotype-specific antigenic differences between vaccine and wild-type MuVs as well. In addition, a poor linear correlation between mumps-specific IgG concentrations and neutralization titers was observed in this study, indicating the concentration of MuV-specific IgG could not fully reflect the neutralizing antibody titer in serum. Therefore, it is highly recommended to provide a second dose of MuCV to preschool children to increase MuV neutralizing antibody titers and use MuV cross-neutralization test as preferred tool for assessment of mumps-containing vaccine effectiveness on wild-type MuVs. This is the first report to assess the effectiveness of one-dose Chinese MuCV against wild-type genotype F MuVs, which would be benefit for the development of mumps vaccination strategy.
为了阐明中国内地一剂次腮腺炎含毒活疫苗（MuCV）的保护效果，我们研究了 HN 基因的抗原变异和 MuCV 与野生型 F 基因型腮腺炎病毒（MuV）之间的交叉中和能力。共分析了 2001 年至 2015 年期间获得的代表 F 基因型 MuV 的 70 株 HN 基因序列、两种 MuCV 株系、139 对接受一剂次 MuCV 接种的婴儿接种前和接种后的血清样本。在中国内地流行的 MuCV 和野生型 F 基因型 MuV 之间的潜在抗原表位观察到了基因型特异性的氨基酸变异。一剂次 MuCV 诱导的腮腺炎中和抗体滴度普遍较低。此外，疫苗株和野生型毒株之间的中和滴度存在显著差异。可以得出结论，一剂次 MuCV 对野生型 F 基因型 MuVs 具有交叉保护作用，但效果有限，这可能是由于 MuCV 接种剂量不足以及疫苗株和野生型 MuVs 之间的基因型特异性抗原差异所致。此外，本研究中观察到腮腺炎特异性 IgG 浓度与中和滴度之间呈较差的线性相关性，表明 MuV 特异性 IgG 浓度不能完全反映血清中的中和抗体滴度。因此，强烈建议为学龄前儿童提供第二剂次 MuCV，以提高 MuV 中和抗体滴度，并将 MuV 交叉中和试验作为评估野生型 MuVs 含 Mu 疫苗有效性的首选工具。这是首次评估一剂次中国 MuCV 对野生型 F 基因型 MuVs 的效果，这将有助于制定腮腺炎疫苗接种策略。
