McNabb Leanne, McMahon Amy, Woube Ezana Getachew, Agnihotri Kalpana, Colling Axel, Broder Christopher C, Kucinskaite-Kodze Indre, Petraityte-Burneikiene Rasa, Bowden Timothy R, Halpin Kim
CSIRO Australian Centre for Disease Preparedness (ACDP), 5 Portarlington Road, Geelong, VIC 3220, Australia.
Private Consultant, Melbourne, VIC 3000, Australia.
Viruses. 2025 Feb 28;17(3):354. doi: 10.3390/v17030354.
Hendra virus (HeV) is a bat-borne zoonotic agent which can cause a severe and highly fatal disease and can be transferred from animals to humans. It has caused over 100 deaths in horses since it was discovered in 1994. Four out of seven infected humans have died. Since the release of the HeV vaccine (Equivac HeV Hendra Virus Vaccine for Horses, Zoetis Australia Pty Ltd., Rhodes, NSW 2138) in Australia, there has been an urgent requirement for a serological test for differentiating infected from vaccinated animals (DIVA). All first-line diagnostic serological assays at the Australian Centre for Disease Preparedness (ACDP) incorporate recombinant HeV soluble G glycoprotein (sG) as the antigen, which is also the only immunogen present in the Equivac HeV vaccine. Problems therefore arose in that antibody testing results were unable to distinguish between prior vaccination or infection with HeV. This study describes the development of a HeV DIVA ELISA strategy using recombinant sG and HeV nucleoprotein (N), paired with specific monoclonal antibodies in a competition ELISA format. The validation of this assay strategy was performed using a positive cohort of 19 serum samples representing post-infection sera, a negative cohort of 1138 serum samples representing horse sera collected pre-vaccine release and a vaccination cohort of 502 serum samples from horses previously vaccinated with Equivac HeV vaccine. For the sG glycoprotein, the diagnostic sensitivity (DSe) was 100.0% (95% CI: 99.3-100.0%) and diagnostic specificity (DSp) 99.91% (95% CI: 99.5-100.0%), using a percentage inhibition cut-off value of >36, whereas for the N protein, DSe was 100.0% (95% CI: 82.4-100.0%) and DSp 100.0% (95% CI: 99.7-100.0%), using a percentage inhibition cut-off value of >49. Taken together, these results demonstrate that the HeV DIVA ELISA strategy developed here is now an essential and critical component of the testing algorithm for HeV serology testing in Australia.
亨德拉病毒（HeV）是一种由蝙蝠传播的人畜共患病原体，可引发严重且致死率很高的疾病，并能从动物传播给人类。自1994年被发现以来，它已导致100多匹马死亡。七名受感染的人类中有四人死亡。自澳大利亚推出HeV疫苗（Equivac HeV马用亨德拉病毒疫苗，澳大利亚硕腾有限公司，新南威尔士州罗兹2138）以来，迫切需要一种用于区分感染动物和接种疫苗动物的血清学检测方法（DIVA）。澳大利亚疾病防范中心（ACDP）的所有一线诊断血清学检测均采用重组HeV可溶性G糖蛋白（sG）作为抗原，而sG也是Equivac HeV疫苗中唯一的免疫原。因此出现了问题，即抗体检测结果无法区分先前接种疫苗还是感染了HeV。本研究描述了一种使用重组sG和HeV核蛋白（N）的HeV DIVA ELISA策略的开发，该策略在竞争ELISA形式中与特异性单克隆抗体配对。使用19份代表感染后血清的阳性血清样本队列、1138份代表疫苗发布前采集的马血清的阴性血清样本队列以及502份先前接种过Equivac HeV疫苗的马的血清样本接种队列，对该检测策略进行了验证。对于sG糖蛋白，使用>36的抑制百分比临界值时，诊断敏感性（DSe）为100.0%（95%CI：99.3 - 100.0%），诊断特异性（DSp）为99.91%（95%CI：99.5 - 100.0%）；而对于N蛋白，使用>49的抑制百分比临界值时，DSe为100.0%（95%CI：82.4 - 100.0%），DSp为100.0%（95%CI：99.7 - 100.0%）。综上所述，这些结果表明，此处开发的HeV DIVA ELISA策略现在是澳大利亚HeV血清学检测算法的一个重要且关键的组成部分。
