Fowlpox virus: pathogenicity and vaccination of day-old chickens via the aerosol route.

Day-old chickens were given a single fowlpox virus vaccination (strain HP201) either via the aerosol or wing-web route. Both methods induced protective immunity against a wing-web or intravenous challenge with virulent fowlpox virus at 47 days old, although high titred virus preparations were required for successful aerosol vaccination. However, no clinical signs of infection were observed as a result of aerosol vaccination even if invasive strains of Escherichia coli were administered simultaneously.

Fowlpox vaccination: routes of inoculation and pathological effects.

Chickens were vaccinated against fowlpox via the wing web, oral route, drinking water or by aerosol. Using two inoculations of virus, at 5 and 26 days of age, protective immunity was induced in chickens which resisted challenge with a pathogenic fowlpox virus given either via the wing web or intravenously at 46 days of age. Aerosol and wing web vaccination induced slightly better protective immunity than drinking water or oral vaccination.

A recombinant fowlpox virus expressing the hemagglutinin-neuraminidase gene of Newcastle disease virus (NDV) protects chickens against challenge by NDV.

The hemagglutinin-neuraminidase (HN) gene from the Beaudette C strain of Newcastle disease virus (NDV) has been expressed in a recombinant fowlpox virus vector. The HN gene, under the control of the vaccinia p7.5 promoter, was inserted into a nonessential gene in the terminal inverted repeats of fowlpox virus.

A fowlpox virus vaccine vector with insertion sites in the terminal repeats: demonstration of its efficacy using the fusion gene of Newcastle disease virus.

In this paper we report the development and testing of a fowlpox virus vector system. Insertion sites in non-essential regions within the terminal inverted repeats of the virus have been characterised. Foreign genes inserted into these sites are shown to be present in two copies in the resultant recombinant virus.

Insertion of the fusion gene from Newcastle disease virus into a non-essential region in the terminal repeats of fowlpox virus and demonstration of protective immunity induced by the recombinant.

In this paper we report on the identification of non-essential genes in the terminal repeats of the avipox-virus fowlpox virus and the use of these as insertion sites in a vector system. Foreign genes inserted into these sites are shown to be present in two copies in the resultant recombinant virus. To test the potential use of this vector as a live vaccine the fusion gene of Newcastle disease virus has been inserted into a vaccine strain of fowlpox virus and inoculated into chickens.