Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K39/0003—Invertebrate antigens

Definitions

• the present invention relates to vaccines, particularly anthelmlnthic vaccines.
• parasitic nematodes may have altered their antigen profile to one which resembles that of the host so that in a natural infection, vigorous immunological reactions are not provoked by important (protective) parasite antigens. This would also occur following vaccination with killed preparations or extracts of the nematodes.
• a third possibility is that the readily abundant L3 developmental stage of parasites which have been used as a source of antigens in the majority of these studies may not contain the potentially protective antigens associated with the parasitic L4, L5 and adult stages of the nematodes. Limited availability of the parasitic stages precludes their use in large scale vaccines even if they were protective as these parasitic nematodes cannot be readily cultivated In vitro beyond the L3 stage.
• the present invention results from the discovery by the present inventors that nematode species which are non parasitic to mammals or birds contain antigens which 'cross react with antibodies produced by mammals or birds which have been infected with or vaccinated with extracts of parasitic nematodes. Therefore it is considered that vaccine preparations derived from a readily cultivated species of nematode non-parasitic to mammals or birds may be used to vaccinate and successfully protect mammals or birds from infections by nematode species which are parasitic to said mammals or birds, even though the species used to derive the vaccine is not the same and may be classified in a - 3 - different order or even a different class from the parasitic species.
• a vaccine preparation for the vaccination of mammals or birds against infections by nematodes parasitic thereto comprising an homogenate, or an extract thereof, of at least one species of nematode which is non-parasitic to mammals.
• a method of vaccinating mammals or birds against parasitic nematode Infections comprising vaccinating the mammal or bird with an effective amount of a suspension, homogenate or extract of a nematode species which is not parasitic to said mammals or birds.
• the vaccine preparation comprises a suspension of at least one species of a nematode, non-parasitic to mammals or birds, wherein the nematodes have been killed or inactivated.
• the vaccine preparations of the present invention are adapted for introduction into the mammalian o * avian system preferably by injection. Therefore, preferably the homogenate and/or extract is sterilised by, e.g. filtration through a small pore filter, the inclusion of antibacterial compounds, formalinisation or other methods known in the art ' . When killed nematode suspensions are used, the nematodes are killed by methods known to those skilled in the art, such as by formalinisation.
• the active ingredients in the vaccine preparation may be delivered in the presence of any of the adjusments known in the art of the vaccine preparation, such as aluminium salt precipitates or oily based adjuvants such as Freund's adjuvants.
• the amount of active ingredients incorporated into the vaccines will vary depending on the size of the animal or bird being vaccinated, the adjuvant used and the purity of the active ingredient. Thus doses from as little as 10 ⁇ g to 500 mg of dry weight of material may be required. Preferably dosage will be in the range of 50 ⁇ g to lmg.
• the species of nematode used for incorporation into the vaccine will preferably be readily cultivated in vitro. This enables the availability of sufficient quantities of all stages of development for incorporation into a commercial vaccine. More mature developmental stages may quantitatively and/or qualitatively be a superior source than juvenile forms.
• Figure 1 illustrates the immunological cross reactivity between parasitic and free living nematodes.
• Figure 1A demonstrates that antiserum from sheep vaccinated with homogenates of Haemonchous contortus adults, a parasitic nematode, reacted with antigens from homogenates of free living nematodes.
• Figure IB demonstrates that antiserum from sheep vaccinated with homogenates of Haemonchous contortus larvae reacted with antigens from homogenates of free living nematodes.
• Figure 1C demonstrates that antiserum from sheep vaccinated with homogenates of Stelnernema feltiae, a free living nematode, exhibits cross-reactivity with homogenates of parasitic nematodes.
• the vaccinating nematode need not be a member of the same family, superfamily, suborder, order or possibly even class as the parasitic species.
• a member of the order Rhabditida (Stelnernema feltiae Mexican) can provide protection of sheep against infection by a member of the order Strongylida (Haemonchus contortus) . Therefore a large number of species would be suitable for incorporation into a vaccine but would preferably be readily cultivated in vitro such as are members of the
• Stelnernema e.g. S_. feltiae
• Caenorhabditis e.g. C.elegans
• Heterorhabditis e.g. H. heltiothldis
• US Patents 4,178,366 and 4.334,498 disclose methods for large scale iri vitro cultivation of such nematodes.
• the parasitic nematode species against which vaccination would be expected. to be effective are similarly numerous. In the example presented, protection is observed against a member of the order Strongylida (Haemonchus contortus) by vaccination with extract from a member of the order Rhabditia (Stelnernema feltlae Mexican) .
• Trichinella spiralls infections of pigs, Toxascaris leonina or Uncinarla stenocephala infections of cats and Ancylostoma caninum or Trichurls vulpls infections of dogs would be expected to be effectively vaccinated against.
• the vaccine would be expected to be effective against nematodes which parasitise tissues other than gastro-intestinal tract.
• the vaccine would be expected to be effective against infections of the circulatory system of man by larvae of Texocara spp and of the circulatory system of dogs by Dirofilaria immitls as well as infections of the circulatory system, urogenital system, respiratory system, skin and subcutaneous tissues of these and other species of animal. It should be noted that this list is by no means complete. The invention will be further described with reference to the following examples. Example 1
• Fig 1A Haemonchus contortus adults
• Fig IB Haemonchous contortus infective larvae
• Fig IB Stelnernema feltlae larvae
• Example 2 Three sheep were vaccinated with an homogenate obtained by ultrasonication of Stelnernema feltlae (Mexican) . The sheep received two vaccinations subcutaneously in the absence of adjuvant four weeks apart, each vaccination being the equivalent of 83mg wet weight of nematodes per kg body weight of sheep. Three weeks after the second vaccination the sheep and five non vaccinated infection controls were challenged with 10,000 infective larvae of Haemonchus contortus. On days 23, 27, 29, 33, 36 and 40 post infection faecal egg counts were performed on all sheep. The result (eggs/g faeces) are presented in the Table 1, below. - 7 -

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• Immunology (AREA)
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• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Medicines Containing Antibodies Or Antigens For Use As Internal Diagnostic Agents (AREA)

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• 1985
  • 1985-11-14 ES ES548889A patent/ES8705231A1/es not_active Expired
  • 1985-11-14 IL IL77061A patent/IL77061A0/xx unknown
  • 1985-11-15 NZ NZ214215A patent/NZ214215A/xx unknown
  • 1985-11-15 EP EP85905735A patent/EP0201568A1/en not_active Withdrawn
  • 1985-11-15 WO PCT/AU1985/000282 patent/WO1986002839A1/en unknown
  • 1985-11-15 GR GR852768A patent/GR852768B/el unknown
  • 1985-11-15 ZA ZA858789A patent/ZA858789B/xx unknown

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