CA1036439A - Ballistic inoculation of animals and projectile therefor - Google Patents

Abstract

Abstract of the Disclosure Ballistic projectile containing an antigen and method for inoculating animals comprising the non-lethal, ballistic implantation of a projectile containing antigen totally within a living animal. Following implantation, the antigen is released in situ in the animal in response to the fluids and cells of the animal body.

Description

-BALLISTIC INOCULATION OF ANIMALS AND
PROJECTILE THEREFOR

~ he present invention relates to the lnocula-tion of living animals~ More particularly the inventlon relates to a ballistic pro~ectile contalning an antigen and a method for conveniently deliverlng the antigen to the animal from a remote location, which method comprises the non-lethal, ballistic implantation of a proJectlle containing an antigen totally within a living animal body and the release of the antigen in situ in the animal bodyO
The vaccination of domestic and wild animal.s is normally performed by in~ection o~ a vaccine in liquid ~orm from a syringe having a sharp, smooth, small diameter needle for minimal wound~ngO This method of vaccination requires the capture and confinement of the animals so that the vaccination can be accomplished, a difficult and time consuming process, particularly with wild animal~O Moreover3 multiple inoculations are some-~imes necessary to achieve a desired effect, due to the inability of the animal body to efficiently assimilate the amount of inoculant required in a single applicatlonO
An important disadvantage in administerlng liquid vaccines by syringe lnvolves the preparation of the vacclne D The vaccine is manufactured in a con-centrated, freeze-drled form and must be reconstituted prior to use of the vaccine~ The dry vacclne is more stable than the llquid form and can be shipped ~nd stored under refrigerated conditions, usually le~s than 4G Co 3 until reconstituted for use~

1~6~
When prepared ~or use in the anlmal, the user reconstltutes the vaccine with a sterile liquid provlded by the manufacturerO The reconstituted vaccines must be maintained in a cool envlronment (eOgO, ice-bath temperatures) to lnsure the quality and activlty o~ the vaccinec While the quality of the dried vaccine can be carefully controlled by the manufacturer, the quality and dosage accuracy of the reconstituted vaccine is limlted by the care exercised by the ultimate userO
In practice, several animals may be inoculated with the same needle and disease can be actually trans-mitted to healthy animals by these convent~onal proceduresO
Various methods of increasing the immune response to inJected antigens are knownO Decreasing the solubility of antigens by administering them as emulsions in various oily materials or adsorbed onto poorly soluble materials, such as aluminum hydroxide, increases the residence time of the antigens in the body and does produce an increased immune responseO ~lowever, these emulsions and suspensions are difficult to administer by needle and syrlnge, and undesirable tlssue reactions may also occur.
: Bacterial cells or extracts can also be added to the antigen preparation as ad~uvants to provoke an increased immune responseO Because adJuvants are not passive agents, their use is limited, since the animal may become sensitive to the ad~uvant or the response to the ad~uvant may be undesirableO For example, myco-bacteria cannot be used as ad~uvants for cattle vaccination since the animals become tuberculin positiveO

- 2 -~L~3643~
Multiple in~ections of antigen spaced over several weeks or months, iOeO booster shots, will usually result in an increased antlbody production compared to a single in~ection~ These multlple in~ections are uneconomical and time consumingO
According to the present invention, there is provided a ballistic pro~ectile containing an antlgen and adapted to release the ant:igen in situ in a living animal body One aspect of the invention relates to a ballistic pro;ectile capable of penetrating the epidermal covering of a living animal body, lodging totally within the body~ and presenting an antigen to the living body, the antigen being released and assimilated by the body 15 fluids and cells surrounding the implanted pro~ectlleO
A further aspect Or the invention relates to a unique method of inoculating living animals, partic-ularly cattle and other domestic livestock9 wherein a pro~ectile containing an antigen is ballistically implanted totally within a living animal body, there-after releasing the antlgen into the animal body in response to the fluids and cells of the animal bodyD
This method of inoculation provides several advantagesO
The ballistic method of implantation using the pro~ec-tiles disclosed herein eliminates the need for actualhuman contact with the living animals in order to effect inoculationO The pro~ectiles used in the ballistlc inoculation are also adapted to contain antigens in a stabilized, dried form until released and absorbed in situ by the animal's fluids and cells and preparation ~36~3~
o~ the antigen-containing ballistic pro~ectiles can take place under sterile, controlled conditions and ; accurate dosages provlded as desiredO The full dosage is then available to the animal and can not be partially "dribbled" away as can happen with faulty syringe tech-niquesO
Furthermore, tests on beef cattle such as Angus, Herefordj Shorthorn, and the like, following inoculation wlth Infectious Bovine Rhinotracheitls (IBR) vaccine according to the present invention, suggests that the effect of the antigen, iOeO, the animal's response to the antigen, is greatly increased when the animals are lnoculated by the present method compared to conventional syringe inoculationsO It is not clearly understood why this surprising effect is achieved using a ballistic inoculationO However, it is believed the trauma at the wound site caused by ballistic implanta-tion may stimulate the defense mechanisms of the body, thereby provoking an increased immune response and heightened antibody productionO
Ballistic inoculation of beef cattle with antigen has been found particularly effectiveO In a preferred embodiment, a small ballistic pro~ectile having a conical nose and a-cavity opening to the rear of the pro~ectile is loaded with a given dose o~ antigen, preferably a freeze-dried vaccineO The proJectile is then propelled into-the flesh of the animal from a distance, using an air powered rifleO The pro~ectile lodges under the epidermal covering of the animal wlth the implant site showing a minimal amount of-swelling ~ Q36~39 or hematomaO On lodglng within the animal, the body fluids and cells Or the animal surrounding the pro~ectlle rehydrake or otherwise release and absorb the antigen which then actlvates the animal's defense mechanisms, whereby the desired antibodies are produced rendering the animal immune to specific diseasesO
The present invention can be illustrated with reference to the drawings wherein several:embodiments of pro~ectiles useful in the present invention are shownO
FIGURE 1 is a perspective view of one embodiment of a balllstic pro~ectile adapted to receive, carry and release an antigenO
FIGURES 2 and 3 are cross sectional views of alternate embodiments of pro~ectiles capable-of carrying and releasing an-antigenO

Referring to FIGURE 1, there is shown a cylindrical, ballistic pro~ectile 10 comprlsing a conical nose 12 and annular walls 14 defining a generally cylindrical cavity 16 with an opening 18 at the base of the pro~ectileO A ballast shown generally at 20 may optionally be included to modify the in-flight character-istics o~ the ballistic pro~ectileO This projectile is particularly sulted to accept, retain, and release an antigen, as will be more fully described hereinafterO
Pro~ectile 10 can be made of any material which is capable of being projected with sufficient ~orce to penetrate a living animal body and which will main$ain its integrity, eOgO will not shatterg on impa~ting and entering the animal bodyO Any of the numerous biomedic-ally approved plastics can be used with advantage and ~lQ36~3gl can be selected from among those which are elther solubleor insoluble in the animal body~ Exemplary of useful insoluble materlals are the synthetic organic polymers such as the polyolefins, eOgO~ polyethylene and poly-propylene; polysilsxane; polyamides, such as nylon;fluorinated hydrocarbon resins; ABS polymers (acryloni-trile-butadiene-styrene polymers) and the likeO A
suitable class of polymers which are soluble ln animal bodies, eOg cattle, are the cellulose derivatives such as hydroxy propyl cellulose, available commercially from the Hercules Powder CoO under the trademark "Klucel".
The use of soluble pro~ectiles can be particularly advantageous since after implant the pro~ectile will be solubilized in and eliminated from the animal's body, eliminating the need to retrieve the pro~ectile.
FIGURE 2 shows a projectile 10 with conical nose portion 12 and annular walls 14 defining a cavity 16 which contains antigen 22 thereinO Sealing cap 24 is op~ional and can be added for additional protection of the pro~ectile contents during storage and launching if desiredO Cap 24 can be made of a soluble materlal whereby the cap can dissolve in the animal body after being implanted and expose the antigen 22 to the animal body fluidsO
Alternatively, cap 24 of FIGo 2 can be removably fastened to the proJectile 10 in which case the cap can be removed prlor to launchlng or can be constructed to separate from the pro~ectile during launching, in flight, or at impact prior to entering the animal bodyO A preferrecl embodiment comprises a :1~36~39 cap 24 spot fastened to pro~ectlle 10 by heat sealing or by adhesive means (not shown) whereby the force exerted on cap 24 during launching causes the cap to bow or buckle an amount sufficient to fracture the : 5 adhesive bond and release the cap after leaving the launching instrument, eOgO, a compressed air gun As noted above, the body of pro~ectile 10 can be made of a soluble or insoluble material, as desiredO As can be appreciated, the pro~ectile 10 may contain any number o~ compartments or cells in various forms which cells may contain antigens which are alike or di~ferentO
Thus, an embodiment wherein a plurality of cells are distributed longitudinally in the cavity and opening at the base of the pro~ectile is also contemplated whereby a plurallty of antigens contained therein could be release simultaneously.
A further embodiment is shown in FIGURE 3 wherein cavity 16 is divided into compartments 16a and 16b by soluble end cap 30 and seal 320 Antigens 22a and 22b are shown contained within compartments 16a and 16b and can be the same or differentO End cap 30 and seal 32 can be chemically similar or different, having similar or different solubilities in animal body fluidsD
This embodiment provides a convenient means for releas-ing consecutive doses of antigena in situ at spacedintervalsO Materials which may be used for the end cap 30 or seal 32 are any of the materials which are solid at room temperature and which will me}t, solubilize, deBrade or otherwise mobilize to release the contents 3Q sealed thereinO Cap 30 may also be releasably adhered ~L~369L3S~
to proJectile 10 as is cap 24 descrlbed in FIGURE 2 aboveO
As illustrated in the drawings, the pro~ectiles o* the present invention have been shown with recessed cavities generally cylindrlcal in nature, opening at the base o~ the proJectile and deflned by annular pro~ectlle wallsO However~ other recesses or ~avities which vary as to location or shape can be utilized with advantageO Thus, one or more cavities which are rectangular or triangular rather than rounded are contemplated as well as cavities which are straight, twisted, or constrictedD Moreover, the cavities need not be provlded with an opening at the base o~ the pro~ectile and they may extend transversely of the pro~ectile with access at the sides or other portion of the proJectile~
The proJectiles of the present invention are adapted to be implanted into living animal bodies by ballistic means such as by launching or "sho~ing" the proJectiles from a convenlent distance with small arms or other launching devices powered by expanding gas means such as explosive charges or compressed gases, preferably airO When properly launched, the proJectiles will penetrate a llving animal body ln a non-lethal manner and come to rest within the bodyO The depth of penetration of the pro~ectile can be controlled by balancing the relationship between the mass of the proJectile and the velocity of the proJectile at impactO
The design of the pro~ectlle can vary, and conventional designs useful herein are known in the artO The ~36439 pro~ectlle design can be varied to achleve the desired degree o~ penetration into the body-as well as to achieYe the desired performance with respect to a wide range of impact velocitles and a wide range o~
animalsO Many texts are available to those skllled in the ballistics art which teach operatlve deslgns for the ogival and other portions o~ the pro~ec~ile~ See, for example, Hayes, "Elements of Ordnance", John Wiley and Sons~ IncO, New YorkO It is generally preferred that the p`ro~ectile have an elongated body with a tapered nose portion which may be conical as shown in the accompanying drawings9 rounded or the likeO A
proJectile design similar to that shown in the FI~URES
the drawings has been found e~fective for the intra-muscular implantation of a o25 caliber pro~ectile intothe flanks and necks of beef cattle at a distance of about 20 to 40 ~feet (6-12 meters)~ The pro~ectile should be capable of penetratlng into and through the body tissue to the desired depth for maximum effectiveness depending on whether subcutaneous or intramuscular treatment is desiredO The polnt at ~ich entry into the living body is effected can readily be determined for maximum effectiveness utilizing minimum forceO
Antlgens, iOeO materials which when admln-istered to an animal will cause the ~ormation of anti-bodies by the animal3 such as the viruses, bacteria and toxoids are well known in the art and are useful in the practice o~ this inventionO Particularly useful viruses, and bacteria are the vacclnes and bacterlns, iOeO pre-paratlon of viruses or bacteria (live or killed) used ~ g _ - - `
1(~36~3~
to protect against a specific diseaseO
Vacclnes can comprise either the kllled or : llving virus and can be wild (pathogenic) or attenuatedO
A preferred vaccine prepared from llving, attenuated virus is the previously mentioned IBR vaccineO Yet another useful vaccine is the hoof and mouth vaccine prepared from killed, wild virusO
The bacterins can comprise living or killed bacteria which may be wild or attenuated. Exemplary of the bacterins prepared from live bacteria is the anthrax bacterin prepared from anthrax spores~ a live, attenuated bacteriaO Bacterlns prepared from killed bacteria are exemplified by the black leg Clostridium, a killed, wlld bacteriaO
As mentioned above, toxoids can also be con-veniently administered by the practice of the present inventlonO For example, equines may be inoculated with a tetanus toxoid to protect against tetanusO Other antigens whlch may not be considered viruses, bacteria, or toxoids, eOg. the allergenics, such as the pollens, which may produce antibodies in living animals, are also suitable for use in the present inventionD
In the practice of the invention, the antigens are generally prepared in liquid form, deposited in the cavity of the pro~ectile and dried, preferably by lyophil~ationO Alternatively, the antigens can be sealed or otherwise contalned ln the pro~ectlle in liquid ~orm, but the dry form is preferred since the antigens are more stable in that form. ~here use is made of a projectile whose polymer body is soluble in the fluids and cells of the animal body, the antigens are advantageously distributed throughout the soluble polymer body.

~L~3~3~
After loading the pro~ectlles wlth antigen, the pro~ectiles can be stored at reduced temperatures, e~gO less than about 20~ CO and preferably about 4 CO~
for extended periods of time until used for inosulationO
When the pro~ectile has been ballistically implanted into the animal body~ the fluids and cells o~
the body act to release and/or rehydrate the antigen which then activates or stimulates the animal's de~ense mechanisms provoking an immune-response and increased antibody productionO
As noted~previously, the projectile is adapted to penetrate and lodge within the animal body in an area which is effective to release the antigen and which does not harm the animalO For example, the flanks and neck muscles of cattle are ideal inoculatlng areas for many antigens The penetratlon o~ the pro~ectile neaessarily causes some minimal woundlng of the animal, but the wound is non-lethal and the trauma ls slight. Experi-ence with beef cattle has shown that bleeding from the pro~ectile entry site ls minimal, generally showing only a small circular spot of blood about 10 mm in diameter on the hide surface when a O~5 callbre pro~ectile is usedO The lmplant sites will heal within a few days without any overt sign of infection3 and unless specifically markedj locating the wound site is difficulto Surglcal removal of the pro~ectiles several days after lmplantatlon revealed no abscesse~ or gross inflamation surrounding the pro~ectllesO
Though the effects are mlnimal, the slight trauma produced at the wound slte by the ballistic ~é~36~39 implantation appears to be advantageous in the practice of the present inventlon since this trauma apparently stimulates antibody production ln some manner causing an increased immune response compared to antigens applled by conventional means9 eOgO in liquid form from syringesO
A preferred antigen-containing, ballistic pro~ectile suitable for the vacclnation of cattle accord-ing to the present invention is prepared by sterilizing~
in ethylene oxide, a polypropylene projectile about 005"
(1025 cm) long, 0025" ~oO6 cm) in diameter, and having a conical nose portionO The proJectile preferably has a cavity in its base sufficiently large to contain 0005 ml of a liquid such as water. A typical sterilization pro-gram would involve exposure Or the pro~ectile to a 12oomg/liter ethylene oxide atmosphere for 100 minutes at 60 C~ ~ollowed by removal of~the residual ethylene oxide under a vacuum of 2 mm Hg for about 18 hours at The sterilized pro~ectile is then loaded with an antigenO A useful antigen for cattle is a modiried (attenuated) live vlrus vaccine such as Infectious Bovine Rhinotraoheitis (IBR) vaccine, which is available commercially from Anchor Laboratories, IncO under the trademark "Anchor IBR-VAC~o Typically, a (10-dose) vial of the vaccine is reconstituted with a 005 ml of sterilized waterO The vaccine vial is rotated slowly to thoroughly wet the contents and allowed to stand 30 minutes on lceO Samples of 0005 ml each are removed using sterile, disposable 0005 ml capillary pipettesO
The pipette contents are each transferred to separate 1~1369L39 tubes containing one milliliter of sterile water, rinsing the pipette with the receiving fluido The samples are then assayed ~or virus tlter by standard laboratory technlques such as the serum neutralization or plaque reduction methods, which procedures are outlined in "Recommended Standard Laboratory Techniques for ~iagnosing Infectious Bovine Rhinotracheitis, Bovine Virus Dlarrhea, and Shipping Fever ~Parainfluenza-3)", Committee for Recommended Standard Techniques for ; 10 Diagnosing Bovine Respiratory Disease, Proceedings of the 75th Annual meeting, UOSO Animal Health Association (1971)~
The ca~ities of the previously sterilized proJectiles are each loaded with 0O05 ml of the vaccine solutionO The vaccine is then frozen at about -78 C0 and lyophilizedO A~ter lyophilization, the pro~ectiles are placed in individual sterile, marked tubes and stored at about 4 CO until used for vaccinationO
If desired, the liquid vaccine can be absorbed in or adsorbed on approprlate substrates such as sterile blotter paper, a fibrous material such as a cotton wad, or other compatible sterile substrate from which the vaccine can be rehydrated or otherwise released while in the animal bodyO
Yet another means of carrying the vaccine in the pro~ectile is to seal the vaccine in a release-sus~ainincJ ~atrlx as disclosed in Uni~ccl S~a~cs l'a~cnt No.

3,948,263 issued on April 6, 1976 to the assignee of the present application. A _____-__ 1~6~39 convenient method of pro~idlng the proJectiles with a sustained release vaccine comprises reconstitutlng the vacclne with a 5% aqueous solutlon of hydroxypropyl cellulose binderO Lyophilizlng this vaccine solution in the pro~ectile cavity provides a vaccine sealed in a body-fluid-soluble3 solid matrix which slowly releases the vaccine in response to the animal body fluids.

,, A further optional feature comprises the use of a removable cap to secure or protect the contained antigen up to and optionally including the time of launching the pro~ectile as-described previously with respect to the embodiment shown in FIGURE 2.
The vaccine-containing projectiles prepared as described above can be used to inoculate beef cattle against Infectlous Bovine Rhinotracheitis by ballistic-ally implanting the pro~ectile $ntramuscularly in the cattle, preferably in the neck muscles of the cattleO
For example~ the pro~ectiles described above can be propelled with a o25 calibre air powered rifle at the large ne¢k muscle in the upper portion of the neck of the cattle from a distance of about 20 feet (6 meters)0 The pro~ectiles exit the-muzzle of the air rifle with a muzzle velocity of about 900 feet per second (275 metersJsec) and will penetrate the hide on the necks of the cattle and lodge in the muscle at a depth of about 1 to 2 inches ~205 - 5 cm) beneath the skin, thereafter releasing the antlgen contained thereinO
-To determine the effect of the vacclne inoculation on the cattle, blood samples are taken from ; 30 the cattle prior to ballistic implantation of the - 14 _ ~36~39 vaccine-contalning pro~ectiles and periodically after implan~O The blood s~mples are assayed for IBR vlrus-neutraliæing antibody by a serum neutralization technique referred to previously hereinO By the 14th to 21st day 5 following lmplantation~ significant titers of viru~
neutralizing antibody are noted at levels which are sufficient to protect the caktle from IBR challengeO
Beef cattle inoculated with IBR vaccine accord-ing to the present-invention will-show a surprisingly increased immune response when compared with cattle inoculated in the conventional mannerO This can be evidenced by visual observation of cattle-which have been challenged by exposure-to IBR virus as well as by antibody titers of the exposed animals. The increased response produced by balllstic implantation of the antigen is particularly manifested by higher antibody counts than produced by conventlonal vaccination tech-niques and/or by a greater percentage of the animals of a given group reaching a protectlve level of antlbody count than would be achieved by conventlonal syrlnge vaccinationO

Claims (8)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A ballistic implant shaped for penetrating the epidermal covering of a living animal body and lodging totally within the tissues of the animal body, said implant consisting essentially of a biologically compatible polymer body and an antigen contained within the polymer body in a manner permitting release of said antigen in response to the fluids and cells of the living animal body.

2. A ballistic implant according to claim 1 wherein said antigen is contained within a cavity opening to the rear of said polymer body.

3. A ballistic implant according to claim 2 wherein said cavity is sealed by a removable cap.

4. A ballistic implant according to claim 1 which includes ballast means within the polymer body.

5. A ballistic implant according to claim 1 wherein said antigen is in a solid form.

6. A ballistic implant according to claim 1 wherein said polymer body is soluble in the fluids and cells of said living animal body.

7. A ballistic implant according to claim 6 wherein said antigen is distributed throughout the soluble polymer body.

8. A ballistic implant according to claim 6 wherein said soluble polymer body comprises hydroxy-propyl cellulose.