Department of Medical Microbiology and Infectious Diseases, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
National Microbiology Laboratory Branch, Public Health Agency of Canada, Winnipeg, MB R3E 3R2, Canada.
Viruses. 2024 Sep 8;16(9):1434. doi: 10.3390/v16091434.
Recent mumps outbreaks have been observed in vaccinated young adults due to the mumps virus (MuV) of genotype G, whereas the current vaccine is a mixture of two genotype A strains. These outbreaks could be attributed to waning vaccine immunity or the antigenic differences between the HN and F glycoproteins in the vaccine and circulating MuV. These glycoproteins are essential targets for the immune system, and antigenic variations may reduce the recognition of mumps antibodies, rendering the population susceptible to the MuV. We established stable cell lines expressing the MuV glycoproteins to study cross-reactivity between genotype A and genotype G. Cross-reactivity between the genotypes was evaluated via immunofluorescence using patient sera from vaccinated individuals, infected individuals, and vaccinated individuals infected with genotype G. Titer ratios showed that the vaccinated individuals exhibited a titer 3.68 times higher for the HN protein and 2.3 times higher for the F protein when comparing genotype A with genotype G. In contrast, the infected individuals showed a lower titer for genotype A compared with genotype G, at 0.43 and 0.33 for the HN and F proteins, respectively. No difference in titer ratio was observed for individuals vaccinated and subsequently infected with mumps. These findings suggest that antigenic variations between the two genotypes may potentially result in immune escape of the circulating strain, resulting in individuals susceptible to the MuV.
最近，在接种过疫苗的年轻成年人中观察到了腮腺炎暴发，这是由于基因型 G 的腮腺炎病毒（MuV）引起的，而目前的疫苗是两种基因型 A 株的混合物。这些暴发可能归因于疫苗免疫力的下降，或者疫苗和循环 MuV 中的 HN 和 F 糖蛋白之间的抗原差异。这些糖蛋白是免疫系统的重要靶标，抗原变异可能会降低腮腺炎抗体的识别能力，使人群易感染 MuV。我们建立了表达 MuV 糖蛋白的稳定细胞系，以研究基因型 A 和基因型 G 之间的交叉反应性。通过使用接种个体、感染个体和接种个体的血清进行免疫荧光分析，评估了基因型之间的交叉反应性。感染个体与基因型 G 相比，HN 蛋白的滴度比基因型 A 低 0.43 倍，F 蛋白的滴度低 0.33 倍。接种后再感染腮腺炎的个体的滴度比值没有差异。这些发现表明，两种基因型之间的抗原变异可能导致循环株的免疫逃逸，使个体易感染 MuV。
