Although ADE has been demonstrated in vitro for encephalitic as well as hemorrhagic flaviviruses [33] it is of greatest in vivo concern with DENV infections where the severe pathogenic manifestations DHF/DSS are correlated with secondary infections and sub-neutralizing levels of heterologous anti-E immunoglobulins [34], [35], [36].
ADE of DENV infection of Fcγ-receptor bearing cells has been ascribed to cross-reactive non-neutralizing antibodies or to neutralizing antibodies at sub-neutralizing levels [ 2].
This is complicated by the concern that sub-neutralizing levels of cross-reactive anti-DENV antibodies might result in more severe disease (i.e., Dengue Hemorrhagic Fever; [ 30– 30].
The inflammation-dampening therapeutic effects of generic high dose intravenous immunoglobulins may override the antibody-dependent enhancement effects that are potentially induced by cross-reactive antibodies or by virus-specific antibodies at sub-neutralizing levels.
Mice administered Ad-CAGoptZGP at 1×104 IFU/mouse demonstrated neutralizing antibody levels similar to levels obtained from mice vaccinated with Ad-CMVZGP at 1×107 IFU/mouse (p = 0.1).
In summary, SARS neutralizing antibody level is positively correlated with clinical severity, and in a portion of the patients with mild infection, a detectable neutralizing antibody response may not develop.
For measurement of neutralizing antibodies level, in cerebrospinal fluid (CSF) and serum, few conventional techniques such as viral neutralization, hemagglutination inhibition (HI), complement fixation tests and immune-florescent staining methods are mostly applied.
In contrast, however, it was reported that virus neutralizing antibody levels to an inactivated feline virus vaccine showed reduced levels of anti-viral antibodies, as well as interferon activity following DMG treatment [ 11].
The neutralizing antibody levels were induced progressively and probably had not reached the highest level until week 12. Considering the seroconversion rate (mice achieving a postvaccination VN titer higher than 40), only the mice received PELC or PELC(A -emulsified cA -emulsifiedines candidatech 100% before 4 weeks).
The FFN provides a more rapid determination of neutralizing antibody levels than is possible with traditional virus neutralization assays that rely on visualization of virus-induced CPE after three or more days incubation to allow for full development of PEDV CPE.
