Duck Embryo Cell Cultures Research Articles

Measles Vaccine Standards Set

Proposed regulations which establish standards for the, production of a German measles (rubella) vaccine were issued by Secretary of Health, Education and Welfare Robert H. Finch on April 3. The regulations apply to vaccines containing a live virus strain known as HPV -77, which is grown in either duck embryo or dog kidney cell culture systems. Experimental vaccines produced in accordance with the standards have undergone extensive community testing in the U.S. and abroad.

Attenuation of duck plague virus and its propagation in cell culture.

Duck plague virus, isolated from infected ducks on Long Island, New York, was propagated in duck-embryonic-fibroblast cell culture. Cytopathogenicity and eosinophilic, granular, intranuclear, inclusion bodies were seen in the infected cells. The inclusion bodies appeared as early as 12 hours after virus inoculation and became more pronounced and abundant at 32–36 hours postinoculation with cell culture. Their formation was inhibited by duck plague hyperimmune serum. The first 9 serial passages in cell culture were lethal for duck and duck embryos. In addition, the 5th, 6th, 7th, 8th and 9th passages were lethal for chicken embryos. Each of the 5th and 7th virus passages in duck embryo fibroblasts were further passaged in duck and chicken embryo cell cultures. The resulting viruses were nonvirulent for ducks, elicited the development of a relatively low antibody level, but afforded protection against challenge inoculation with duck plague virus. An anamnestic response in antibody level occurred following challenge inoculation which was equal to the antibody level of ducks surviving experimental infection.

Live Attenuated Rubella Virus Vaccines Prepared in Duck Embryo Cell Culture

Duck embryo cell culture rubella virus vaccines prepared with the HPV-77 (Meyer-Parkman) and the Merck (B-level attenuation) strains of virus were evaluated in a large-scale family study in the open community and in an institution. Of 265 initially seronegative children vaccinated with the HPV-77 virus in duck embryo cell culture, 97% responded serologically with a geometric mean hemagglutination-inhibiting (HI) titer of 1:53.2. There was no apparent clinical illness and no serologic evidence for contact spread to 262 susceptible siblings or to 34 maternal contacts. The performance of the Merck B-level vaccine in duck embryo cell culture in the smaller institutional study was essentially the same as that of the HPV-77 except that the mean HI titer was almost three times as great (1:148.3). Both vaccines proved safe and efficacious in children, and community studies are in progress in larger numbers of persons.

Live attenuated rubella virus vaccines prepared in duck embryo cell culture. II. Clinical tests in families and in an institution

Live attenuated rubella virus vaccines prepared in duck embryo cell culture. II. Clinical tests in families and in an institution

Live Attenuated Rubella Virus Vaccines Prepared in Duck Embryo Cell Culture

Merck strain rubella virus and Meyer-Parkman monkey kidney attenuated HPV-77 virus were prepared at various levels of attenuation for investigative use in humans and animals. The vaccines were produced in duck embryo cell culture and represented a spectrum which ranged from underattenuation, causing communicable mild rubella, to overattenuation with apparent nonexcretion and inadequate immunization. Merck strain rubella virus at attenuation level B, or possibly C, and Meyer-Parkman HPV-77 virus in fifth passage in duck embryo cell culture appear to present the attributes of an effective noncontagious vaccine. The antibody, produced in children after administration of level C vaccine, persisted undiminished for at least one year. Duck embryo cell culture appeared to be an attractive material for preparing vaccine because it was of a nonmammalian source and because of the relative freedom of ducks from disease.

Live attenuated rubella virus vaccines prepared in duck embryo cell culture. I. Development and clinical testing

Live attenuated rubella virus vaccines prepared in duck embryo cell culture. I. Development and clinical testing

Enhancement of St. Louis arbovirus plaque formation by neutral red.

Experiments with St. Louis encephalitis (SLE) virus have shown that neutral red enhances the plaque size in duck embryo cell cultures. This may represent a new method for genetic studies of SLE virus population. In a mosquito pool specimen NR(+) and NR(-) particles were demonstrated. By intracerebral passage in mice, there is a selection of NR(+) particles. Similar effects were not shown for eastern, western, and California encephalitis viruses. Plaques formed by the latter virus, however, were significantly reduced in number by neutral red.

Electron microscopic characterization of duck plague virus

A virus [duck plague Long Island virulent virus (DPLIVV)] was isolated from ducks in a recent disease outbreak on farms on Long Island, New York. This disease exhibited characteristics similar to duck plague, a disease in ducks endemic to the Netherlands and India and not previously reported in the United States. An attenuated strain of the duck plague virus from the Netherlands was studied morphologically by electron microscopy. Its infectivity for duck embryo cell cultures was also studied. The DPLIVV and the Holland strain were morphologically identical. Furthermore, enzymatic digestion of methacrylate-embedded thin sections of mature virus particles showed that both Holland duck plague-attenuated virus and DPLIVV contained deoxyribonucleic acid. The dimensions of the mature cytoplasmic particle; nucleocapsid diameter ca. 75 mμ, envelope diameter ca. 181 mμ, and other characteristics would presumably place duck plague virus in the herpesvirus group.

Duck Hepatitis Virus in Duck Embryo Fibroblast Cultures

This communication reports preliminary observations on a field strain of duck hepatitis virus (DHV) in a duck embryo fibroblast culture system. DHV has been propagated through 25 passages in chicken embryo explants (10), 8 passages in chicken embryo cell culture (11), and 7 passages in chicken embryo liver cell culture (8) with no cytopathic changes and with low virus yield. A Japanese strain of the virus was found to be noncytopathic in cultured cells of chicken embryo, duck embryo, chick kidney and duck kidney, but the original liver virus and the chicken embryo 4th-passage virus formed plaques in duck embryo cell cultures (13). It was stated that the plaque-forming activity of this virus required further confirmation. Cytopathic changes were observed in duck embryo kidney cell cultures inoculated with DHV from the 16th through the 26th passages 24 to 36 hours after inoculation (2).

Eastern Encephalitis Virus in Duck Embryo Fibroblast Culture

EASTERN encephalitis virus (EEV) has been propagated and has produced cytopathogenic changes in cultured fibroblasts of chickens embryos,1l10 rats,5'2 and mouse embryos. It has been stated7 that Pekin duck embryo cell cultures supported plaque formation by certain group A arbor viruses but that cytopathogenicity of the viruses in fluid cultures was questionable or undetectable. No other information accompanied that statement. An attempt was made to propagate the virus of EE from ducklings3 in duck embryo fibroblast cultures. The results are reported here.