| abstract |
The present invention provides a vaccine enhancement factor (VAF). Vaccine enhancing factor (VAF) is a nucleotide immunostimulator applicable to in ovo inoculation. A VAF may be one or more different DNA building molecules, each building molecule comprising one DNA molecule and a vector, and each DNA molecule containing one or more genes. Alternatively, gene fragments are included; these genes or gene fragments can each encode a polypeptide having avian virus antigenicity. The time of use of VAF is most preferably 17-19 days after fertilization (in the case of chickens) and the injection site is in the amniotic cavity of the chicken embryo. VAF can be used in combination with general viral vaccines regardless of unit price or multivalent, or live or dead virus. VAF can be used before the use of general virus vaccines, and these virus vaccines are usually used after hatching or hatching chicks, but VAF stimulates the immune utility of the viral vaccines. And it can be improved. |