Robert Nordgren

Immunogenicity of Fowlpox Virus Expressing the Avian Influenza Virus H5 Gene (TROVAC AIV-H5) in Cats

ABSTRACT Vaccination of cats with fowlpox virus expressing the avian influenza (AI) virus H5 hemagglutinin gene (TROVAC AI) resulted in detectable hemagglutination inhibition (HI) antibody responses to the homologous A/Turkey/Ireland/1378/83 (H5N8) (A/tky/Ire/83) AI virus antigen. The HI antibody responses to heterologous A/Chicken/Indonesia/7/03 (H5N1) (A/ck/Indonesia/03) AI virus antigen were also detected in all vaccinated cats, but only after booster vaccinations. The vaccine described in this study and other poxvirus-vectored vaccines may be of value for the prophylaxis of AI virus-associated morbidity and mortality in mammals.

Domestic goose as a model for West Nile virus vaccine efficacy

West Nile virus (WNV) is an emergent pathogen in the Americas, first reported in New York during 1999, and has since spread across the USA, Central and South America causing neurological disease in humans, horses and some bird species, including domestic geese. No WNV vaccines are licensed in the USA for use in geese. This study reports the development of a domestic goose vaccine efficacy model, based on utilizing multiple parameters to determine protection. To test the model, 47 geese were divided in two experiments, testing five different vaccine groups and two sham groups (challenged and unchallenged). Based on the broad range of results for individual metrics between the Challenged-Sham and Unchallenged-Sham groups, the best parameters to measure protection were Clinical Pathogenicity Index (CPI), plasma virus positive geese on days 1-4 post-inoculation and plasma virus titers, and brain histological lesion rates and severity scores. Compared to the Challenged-Sham group, the fowlpox virus vectored vaccine with inserts of WNV prM and E proteins (vFP2000) provided the best protection with significant differences in all five metrics, followed by the canarypox virus vectored vaccine with inserts of WNV prM and E proteins (vCP2018) with four metrics of protection, recombinant vCP2017 with three metrics and WNV E protein with one. These data indicate that domestic geese can be used in an efficacy model for vaccine protection studies using clinical, plasma virological and brain histopathological parameters to evaluate protection against WNV challenge.

Special Issues around Veterinary Vaccines

Abstract The majority of vaccines licensed for controlling infectious disease of veterinary species today are based on technology that was introduced by Jenner using live vaccines and Pasteur using killed whole organism vaccines 200 and 100 years ago, respectively, yet this former technology has not stopped several successful vaccination programs from being developed. Much of veterinary vaccinology is driven by the realities that exist in raising production animals or working in veterinary practice, where making a living depends on keeping the animals healthy, because it is an industry where vaccines are like insurance policies—protection from events that one hopes never happen. For example, the USDA recognizes these varying levels of protection in the way that they allow label claims: (1) “aids in disease control,” (2) “for the prevention of disease,” and (3) “for the prevention of infection.” Additionally there may be indirect protection, or herd immunity, that results from vaccination of sufficient numbers of animals in a given population resulting in the reduction of the ability of a disease to transmit through the vaccinated individuals. The perception that vaccines provide sterilizing immunity, where the disease agent does not establish an infection, while widely held, is generally unfounded and largely unrealistic. Recent advances, especially in the last 15 years in genomics, proteomics, biotechnology, immunology, pathogenesis, and vaccine formulation and delivery have dramatically changed our approach to vaccine development. When used optimally, vaccines have been shown to prevent disease, reduce the need for pharmaceutical intervention, and improve the health and welfare of animals, and indirectly people as well. The challenge in developing an optimal vaccination program is in dealing with the great diversity that exists within the animal world, and as such there probably is no single optimal program for all occasions. While there is no magic solution to optimizing vaccination programs for animals, nonetheless, a solid understanding of the animal’s innate and environmental risk factors as well as the variables such as stress will enable the development of tailored vaccination schedules that best meets the needs of the animal. The use of vaccines in animal health is not restricted to the protection of morbidity and mortality of the animal hosts themselves, but they are regularly employed as key elements in public health programs. When appropriate biopreparedness, management modeling strategies, and contingency plans of the future are linked with (1) protective DIVA vaccines against zoonoses, (2) effective predictive modeling, and (3) deployable implementation policies, control, and prevention of serious zoonotic diseases of man and animals will become more achievable at local, state, and national levels.