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US4438097A Expired / Lapsed US ⏱️ 0.0 years remaining

Coccidiosis vaccines

Assignee: NATIONAL RESEARCH DEVELOPMENT Corp 66-74 VICTORIA ST LONDON SW1 ENGLAND A BRITISH CORP
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Filing: 1981-09-08
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Granted: 1984-03-20
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Expires: 2001-09-08
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Abstract

Abstract Attenuated E. necatrix suitable for use in the production of a live vaccine is produced by passaging pathogenic E. necatrix in embryonated eggs for a sufficient number of passages i.e. from about 20 up to about 50 or more egg passages. The live egg-attenuated E. necatrix of the invention may be formulated in vaccines, e.g. feed or drinking water vaccines, for prevention and control of coccidiosis in poultry, usually with other strains of Eimeria (i.e. E. acervulina, E. brunetti, E. maxima, E. mivali, E. praecose and E. tenella) as live pathogenic strains thereof or preferably attenuated non-pathogenic lines thereof. In a preferred embodiment the egg-attenuated E. necatrix of the invention is formulated in a vaccine comprising attenuated, precocious E. acervulina.

Inventors

  • 👤 Martin W. Shirley

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 23:37
CPC Classifications
C; C12; C12N; C12N1/00; C12N1/36; A; A61; A61K; A61K39/00; A61K39/002; A61K39/012; C12N1/10

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 30 words
A process for the production of an attenuated strain of E. necatrix, which comprises: passaging a pathogenic E. necatrix in embryonated eggs for from about 20 to about 60 passages.
Claim 2
Dependent Claim 30 words
A process for the production of an attenuated strain of E. necatrix, which comprises: passaging a pathogenic E. necatrix in embryonated eggs for from about 20 to about 60 passages.
Claim 3
Dependent Claim 52 words
A process according to claim 1, in which embyronated eggs are inoculated with sporozoites of E. necatrix and oocysts are subsequently removed from said eggs, and in which during the first n egg passages, where n is a number from 6 to 10, alternate passages are carried out in eggs and chickens.
Claim 4
Dependent Claim 36 words
A process according to claim 1, in which conditions used during in ovo culture include the use of a temperature of from 39° to 43° C. and turning of the eggs at least once per day.
Claim 5
Dependent Claim 16 words
A process according to claim 1, in which the selection pressures comprise selection for precocious development.
Claim 6
Dependent Claim 96 words
A process according to claim 1, in which passaging is carried out in the chorioallantoic membrane of embryonated eggs; sporozoites of E. necatrix are inoculated into said membrane; conditions used during in ovo passaging include the use of a temperature of from 39° to 43° C. and turning of the eggs at least once per day; during the first n egg passages, where n is a number from 6 to 10, alternate egg passages are carried out in eggs and chickens; from 20 to 50 egg passages are used; and oocysts are recovered from the eggs.
Claim 7
Dependent Claim 26 words
A process according to claim 1, in which from about 30 up to about 50 egg passages are used when selection pressures are relaxed during passaging.
Claim 8
Dependent Claim 26 words
A process according to claim 1, in which selection pressures are imposed during passaging and from about 20 up to about 40 egg passages are used.
Claim 9
Dependent Claim 39 words
A vaccine for the prevention and control of coccidiosis in poultry, which comprises: a live attenuated strain of E. necatrix produced by passaging a pathogenic E. necatrix strain in embryonated eggs for from about 20 to about 60 passages.
Claim 10
Dependent Claim 39 words
A vaccine for the prevention and control of coccidiosis in poultry, which comprises: a live attenuated strain of E. necatrix produced by passaging a pathogenic E. necatrix strain in embryonated eggs for from about 20 to about 60 passages.
Claim 11
Dependent Claim 12 words
A vaccine according to claim 8, further comprising food or drinking water.
Claim 12
Dependent Claim 23 words
A method for the prevention and control of coccidiosis in poultry, in which poultry are vaccinated with a vaccine according to claim 8.
Claim 13
Dependent Claim 22 words
A vaccine according to claim 8, further comprising at least one other attenuated non-pathogenic strain of Eimeria in addition to E. necatrix.
Claim 14
Dependent Claim 16 words
A vaccine according to claim 8, further comprising at least one attenuated, precocious strain of Eimeria.

References Cited (Backward Citations)

US3029282A Cited
US3864394A Cited
US4241021A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-03-20 1987-09-19 1988-03-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-03-20 1991-09-19 1992-03-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-03-20 1995-09-19 1996-03-20 $7700.00 Window Closed / Lapsed

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