James Cassandra M, Foong Yvonne Y, Mansfield Josephine P, Vind Azita Rezazadeh, Fenwick Stanley G, Ellis Trevor M
School of Veterinary and Biomedical Sciences, Faculty of Health Sciences, Murdoch University, South Street, Perth 6150, Western Australia, Australia.
Vaccine. 2008 Oct 3;26(42):5345-51. doi: 10.1016/j.vaccine.2008.08.008. Epub 2008 Aug 22.
Control measures for H5N1 avian influenza involve increased biosecurity, monitoring, surveillance and vaccination. Subclinical infection in farmed ducks is important for virus persistence. In major duck rearing countries, homologous H5N1 vaccines are being used in ducks, so sero-surveillance using H5- or N1-specific antibody testing cannot identify infected flocks. An alternative is to include a positive marker for vaccination. Testing for an antibody response to the marker would confirm approved vaccine use. Concurrent testing for H5 antibody responses would determine levels adequate for protection or indicate recent infection, with an anamnestic H5 antibody response requiring further virological investigation. In this study, we have evaluated the use of a TT marker in ducks given avian influenza vaccination. Wild or domestic ducks were tested for antibodies against TT and all 463 ducks were negative. High levels of TT-specific antibodies, produced in twice-TT vaccinated Muscovy ducks, persisted out to 19 weeks. There was no interference by inclusion of TT in an inactivated H6N2 vaccine for H6- or TT-seroconversion. Thus TT is a highly suitable exogenous marker for avian influenza vaccination in ducks and allows sero-surveillance in countries using H5N1 vaccination.
H5N1禽流感的防控措施包括加强生物安全、监测、监视和疫苗接种。养殖鸭的亚临床感染对病毒持续存在具有重要意义。在主要的养鸭国家，同源H5N1疫苗正在鸭群中使用，因此使用H5或N1特异性抗体检测进行血清监测无法识别受感染的鸭群。一种替代方法是加入疫苗接种的阳性标记物。检测对该标记物的抗体反应将确认是否使用了获批疫苗。同时检测H5抗体反应将确定足以提供保护的水平或表明近期感染情况，出现回忆性H5抗体反应则需要进一步进行病毒学调查。在本研究中，我们评估了在接种禽流感疫苗的鸭中使用破伤风类毒素（TT）标记物的情况。对野生或家养鸭进行了针对TT的抗体检测，所有463只鸭均为阴性。在接种两次TT的番鸭中产生的高水平TT特异性抗体可持续至19周。在用于H6或TT血清转化的灭活H6N2疫苗中加入TT不会产生干扰。因此，TT是鸭禽流感疫苗接种的一种非常合适的外源性标记物，并且在使用H5N1疫苗接种的国家中可用于血清监测。
