The microneutralization assay was performed using a 96-well plate format. of needle-free (Agro-Jet?) DNA immunization in chickens. To evaluate the distribution of fluid into superficial or deep layers of subcutaneous tissues after delivery by AgroJet?, 4 or 7 week aged chickens were injected with Rabbit Polyclonal to Histone H3 (phospho-Thr3) a solution containing India ink with this needle-free device at various pressures, ranging from 45 to 55 mm Hg. Three sites (thigh, wing and breast) were used, and biopsies were taken for routine hematoxylin and eosin staining. Representative sections of thigh injections are shown from 7 week aged chickens and were comparable at 4 weeks (data PF-04634817 not shown). While the 48 mm Hg pressure deposited the injectate into the dermis/subcutaneous region (left), the higher pressure injections, 52 and 58 mm Hg, deposited the injectate into the subcutaneous and muscle layers (middle, right). 48 mm Hg consistently provided an optimal pressure to deposit the injectate into the dermis and subcutaneous tissue and was chosen for all those AgroJet? immunizations.(10.74 MB DOC) pone.0002432.s003.tif (10M) GUID:?438F2068-220B-486D-87F1-D9B374002B4E Abstract Background Sustained outbreaks of highly pathogenic avian influenza (HPAI) H5N1 in avian species increase the risk of reassortment and adaptation to humans. The ability to contain its spread in chickens would reduce this threat and help maintain the capacity for egg-based vaccine production. While vaccines offer the potential to control avian disease, a major concern of current vaccines is usually their potency and inability to protect against evolving avian influenza viruses. Methodology / Principal Findings The ability of DNA vaccines encoding hemagglutinin (HA) proteins from different HPAI H5N1 serotypes was evaluated for its ability to elicit PF-04634817 neutralizing antibodies and to protect against homologous and heterologous HPAI H5N1 strain challenge in mice and chickens after DNA immunization by needle and syringe or with a pressure injection device. These vaccines elicited antibodies that PF-04634817 neutralized multiple strains of HPAI H5N1 when given in combinations made up of up to 10 HAs. The response was dose-dependent, and breadth was determined by the choice of the influenza computer virus HA in the vaccine. Monovalent and trivalent HA vaccines were tested first in mice and conferred protection against lethal H5N1 A/Vietnam/1203/2004 challenge 68 weeks after vaccination. In chickens, protection was observed against heterologous strains of HPAI H5N1 after vaccination with a trivalent H5 serotype DNA vaccine with doses as low as 5 g DNA given twice either by intramuscular needle injection or with a needle-free device. Conclusions/Significance DNA vaccines offer a generic approach to influenza computer virus immunization applicable to multiple animal species. In addition, the ability to substitute plasmids encoding different strains enables rapid adaptation of the vaccine to newly evolving field isolates. Introduction The highly pathogenic H5N1 influenza computer virus causes lethal multi-organ disease in poultry, resulting in significant economic losses and a public health concern in many parts of the world. The greatest threats posed by this computer virus are its ability to cause mortality in humans, its potential to compromise food supplies, and its possible economic impacts. Viral maintenance in poultry potentiates the risk of human-to-human transmission and the emergence of a pandemic strain through reassortment. An effective, safe poultry vaccine that elicits broadly protective immune responses to evolving flu strains would provide a countermeasure PF-04634817 to reduce the likelihood of transmission of this PF-04634817 computer virus from domestic birds to humans and simultaneously would protect commercial poultry operations and.