Fig. 2From: Protective efficacy of an inactivated vaccine against H9N2 avian influenza virus in ducksAntibody dynamics of vaccinated ducks. Six-week-old ducks were intramuscularly immunized with the developed inactivated vaccine (H9N2, SH441) The mean HI titers for sera collected weekly or bi-weekly during 37 weeks post-inoculation are shownBack to article page