- Email: [email protected]
Pasteurella hemolytica Vaccines
210
12. 13. 14. 15. 16. 17. 18. 19. 20. 21.
22.
CHARLES
A.
HJERPE'
mortality in feedlot calves: The Bruce County beef project, year two. Can J Comp Med 45:103-112, 1981 Martin SW, Meek AH, Davis DG, et al: Factors associated with mortality and treatment costs in feedlot calves: The Bruce County beef project, years 1978, 1979, 1980. Can J Comp Med 46:341-349,1980 Amstutz HE, Horstman LA, Morter RL: Clinical evaluation of the efficacy of Haemophilus somnus and Pasteu.rella spp bacterins. Bov Pract 16:106-108, 1981 Morter RL, Amstutz HE, Crandell RA: Clinical evaluation of prophylactic regimens for bovine respiratory disease. Bov Pract 17:56-58, 1982 Morter RL, Amstutz HE: Evaluating the efficacy of a Haemophilus somnus bacterin in a controlled field trial. Bov Pract 18:82-83, 1983 Martin SW, Janzen ED, Willson P, et al: A field trial of pre shipment vaccination of calves. Can Vet J 25:145-147,1984 Ribble CS, Jim GK, Janzen ED: Efficacy of immunization of feedlot calves with a commercial Haemophilus somnus vaccine. Can J Vet Res 52:191-198, 1988 Davidson IN, Carpenter TE, Hjerpe CA: An example of an economic decision analysis approach to the problem of thromboembolic meningoencephalitis (TEME) in feedlot cattle. Cornell Vet 71:383-390, 1981 Miller RB, Lein DH, McEntee KE, et al: Haemophilus somnus infection of the reproductive tract: A review. J Am Vet Med Assoc 182:1390-1392, 1983 Chladek DW: Bovine abortion associated with Haemophilus somnus. Am J Vet Res 36:1041, 1975 Van Dreumel AA, Kierstead M: Abortion associated with Hemophilus somnus infection in a bovine fetus. Can Vet J 16:367 -370, 1975 Klavano GG: Observations of Hemophilus somnus infection as an agent producing reproductive diseases: Infertility and abortions. In Proc Ann Mtg Soc Theriogenol. pp 139-149, 1980
Pasteurella hemolytica Vaccines P. hemolytica, biotype A, serotype 1 and/or P. multocida infections of the lung are chiefly responsible for the clinical signs and pathologic lesions of bovine bronchopneumonia and fibrinous pneumonia. The etiology and pathogenesis of bronchopneumonia and fibrinous pneumonia are briefly discussed in the section concerning PI3 virus vaccines. P. hemolytica and P. multocida also cause endometritis, metritis, and occasionally septicemia, with or without accompanying bronchopneumonia and fibrinous pneumonia.
General Considerations Conventional formalin-inactivated, whole-cell, aluminum hydroxide - adsorbed P. hemolytica and P. multocida bacterins have been utilized for more than a half-century. In general, they have been found to be ineffective immunizing agents.1 During the past 5 years, a total of six new P. hemolytica vaccines have been introduced in the United States. Four of these new P. hemolytica vaccines utilize modified-live bacterial agents. The two new inactivated P. hemolytica products are subunit vaccines (see Table 5). The immune mechanisms involved in resistance of the bovine lung to P. hemolytica infections are incompletely understood. It is clear, however, that resistance is greatly enhanced by the presence of serum and bronchoalveolar antibodies to (1) the leukotoxin of P. hemolytica
BOVINE VACCINES AND HERD V ACCINA TION PROGRAMS
211
and (2) certain surface antigens that are present in the bacterial capsule of P. hemolytica AI.2 Leukotoxin is an exotoxin produced by all serotypes of rapidly growing P. hemolytica. It is highly toxic to ruminant alveolar macrophages and neutrophils, which constitute some of the first lines of defense against invading bacteria. It is believed that vaccines that produce antibodies to both (I) leukotoxin and (2) bacterial capsular antigens (in a saline extract of logarithmic-phase P. hemolytica, referred to as carbohydrate protein subunit) are more effective than those that stimulate production of only one of these two types of antibodies. 2 It has been shown that effective live P. hemolytica vaccines stimulate high levels of both kinds of antibodies. 2 P. hemolytica bacterins in oil adjuvants stimulate high antibody titers to carbohydrate protein subunit but not to leukotoxin. 2 Conventional aluminum hydroxide - adsorbed P. hemolytica bacterins also do not stimulate leukotoxin antibody production and stimulate only low titers to carbohydrate protein subunit. 2 Subunit vaccines can be produced that stimulate high levels of leukotoxin-neutralizing antibodies and/or carbohydrate protein subunit antibodies, depending on the extraction process utilized. 2 Vaccines that utilize modified-live P. hemolytica bacteria will not be effective when administered within 7 days after or 3 days before systemic administration of antimicrobial agents. These same vaccines should probably not be administered simultaneously with MLV BVD vaccines, Brucella abortus vaccine, anthrax vaccine, or modified-live anaplasmosis vaccine. Only one modified-live P. hemolytica vaccine is specifically recommended by the manufacturer for administration to cattle arriving in feedlots (Respirvac, Beecham Laboratories, Bristol, TN 37620). Three of the new modified-live P. hemolytica vaccines are one-dose vaccines. Both new P. hemolytica subunit vaccines and one new modified-live P. hemolytica vaccine (Pneumo-Guard H, Norden Laboratories, Lincoln, NE 68521) are two-dose vaccines (see Table 5). General recommendations for use of P. hemolytica vaccines are summarized (see Table 5). Additional information and considerations concerning use of each of the six new P. hemolytica vaccines are discussed below. Respirvac (Beecham Laboratories, Bristol, TN 37620) This is a modified-live bacterial vaccine that is recommended for subcutaneous administration in a single dose to cattle not less than 3 months of age. Immunity develops within 14 days following administration. Annual booster vaccination is recommended. The manufacturer indicates that this vaccine causes no local or systemic reactions and is safe for administration to stressed cattle and to cattle arriving in feedlots. Additional claims are for a reduction of 90% in the extent of P. hemolytica bronchopneumonia and fibrinous pneumonia lesions and for reduced morbidity rates and mortality rates and improved response to treatment in feedlot cattle.
212
CHARLES
A.
HJERPE
Presponse (Langford, Guelph, Ontario, Canada N1K 1E4) This is an inactivated subunit vaccine. The manufacturer recommends that two doses be administered by intramuscular injection, 14 to 28 days apart, to cattle of any age. Annual booster vaccination is recommended. The manufacturer indicates that this vaccine causes no local or systemic reactions and is safe for administration to stressed cattle and cattle arriving in feedlots. In a large feedlot trial involving 2072 cattle, this vaccine was administered once on the day of arrival and again 1 to 5 days later. 3 In comparison with unvaccinated controls, the overall mortality rate was reduced by 49%, retreatments were reduced by 12% and treatment days were reduced by 8.2%. The morbidity rate was not significantly affected. The manufacturer claims that this vaccine stimulates both leukotoxin-neutralizing antibodies and serotype-specific agglutinating antibodies to bacterial surface antigens. Shipguard (Coopers Animal Health, Kansas City, KS 66103) This is a modified-live bacterial vaccine recommended for singledose subcutaneous or intramuscular administration, to cattle weighing not less than 400 lb (181 kg). Annual booster vaccination is recommended. Immunity develops within 14 to 21 days after administration. A systemic, febrile reaction and stiffness or lameness develops following vaccination in some animals. The manufacturer warns against simultaneous administration with Brucella abortus vaccine. Pneumo-Guard H (Norden Laboratories, Lincoln, NE 68521) This is a modified-live bacterial vaccine recommended for intramuscular administration, twice, at a 28-day interval, in the rear quarter of cattle weighing not less than 400 lb (181 kg). Annual booster vaccination is recommended. The manufacturer indicates that, although systemic reactions do not occur, approximately 4% of vaccinated animals show stiffness or lameness and that abscesses occur in less than 1 % of vaccinates. This vaccine is not recommended by the manufacturer for use in stressed cattle. Ninety-four per cent efficacy against experimental challenge with P. hemolytica is claimed. Septimune PH-K (Fort Dodge Laboratories, Fort Dodge, IA 50501) This is an inactivated subunit vaccine that is recommended for intramuscular administration in two doses, 14 to 28 days apart, to cattle of any age. Immunity is achieved by 14 days following administration of the second dose. Annual booster vaccination is recommended. Calves vaccinated prior to 6 months of age should be revaccinated when they are 6 months old. The manufacturer indicates that this vaccine does not cause systemic or local reactions, is safe for administration to stressed cattle, and is recommended for administration to cattle arriving in feedlots. The manufacturer claims that this vaccine contains a high concentration of specific bacterial capsular surface antigens. It does not induce antibodies to leukotoxin.
BOVINE VACCINES AND HERD VACCINATION PROGRAMS
213
Precon-PH (AH Robins, Richmond, VA 23220) This is a modified-live bacterial vaccine recommended for intradermal administration in a single dose to cattle of any age. Immunity develops within 7 to 10 days after vaccination. Booster vaccination is recommended at 6-month intervals. Local reactions may occur at the injection site. The vaccine is not recommended by the manufacturer for use in stressed or recently shipped cattle. A 25 to 40% reduction in the morbidity rate from pneumonia is claimed in animals vaccinated 7 to 10 days before shipping. In field vaccination trials, results have been mixed. In two studies in which cattle were vaccinated with Precon-PH 2 weeks before shipping to feedlots 4.5 and in a third study in which calves were vaccinated upon arrival in a feedlot, 6 morbidity and mortality rates were not significantly affected. In two other trials involving vaccination of calves (1) 2 weeks before shipment to an experiment station and (2) upon arrival in a feedlot, reduced morbidity rates were demonstrated in both cases and a reduced mortality rate was achieved in cattle vaccinated prior to shipment. 7 In a sixth field trial involving young dairy calves, reduced morbidity and mortality rates were obtained during the first month after vaccination. 8 These results were then reversed during the subsequent month (Davidson IN; unpublished data, 1985), so that the net result, by the time the calves were sold, was equivocal. In studies performed at Oklahoma State University, vaccination of cattle with Precon-PH did not stimulate production of the levels of whole-cell agglutinating antibodies that are usually associated with satisfactory immunity.4 All six of these vaccines are relatively new products. It is still too early to predict with certainty which, if any, will stand the test of time and which will fall by the wayside. Since Septimune PH-K does not produce leukotoxin-neutralizing antibodies, it would not be surprising if it proved to be less efficacious than at least some others. Some (if not all) modified-live P. hemolytica vaccines may prove to be excessively stressful for use in feedlot cattle (as well as in other high-stress situations). The time and skill required for successfully performing large numbers of intradermal injections has been a deterrent to widespread acceptance of Precon-PH. Because of the stress that is likely to be associated with administration of the modified-live P. hemolytica vaccines and because the inactivated subunit vaccines require a minimum of 3 weeks to develop effective immunity, it is likely that these new vaccines will find their greatest value and application in beef preweaning and preconditioning programs and on dairy farms and dairy calfraising facilities. In these programs, animals can be immunized at times when they are being subjected to minimal stresses, well before weaning and/or shipping or grouping. It should also be kept in mind that, on some farms and in some situations, pneumonia caused by P. multocida may be more of a problem than P. hemolytica pneumonia. Highly effective control of the pasteurella pneumonia problem will require development of safe and effective vaccine products for both P. hemolytica and P. multocida bacteria.
214
CHARLES
A.
HJERPE
P. multocida Va~cines The P. multocida vaccines presently available are conventional formalin-inactivated, whole-cell, aluminum hydroxide - adsorbed bacterins, which are not considered to be efficacious. The immune mechanisms involved in resistance of the bovine lung to P. multocida infections are poorly understood at present.
REFERENCES 1. Martin SW: Vaccination: Is it effective in preventing respiratory disease or influencing weight gains in feedlot calves? Can Vet J 24:10-19, 1983 2. Confer AW, Panciera RJ, Mosier DA: Bovine pneumonic pasteurellosis: Immunity to Pasteurella haemolytica. J Am Vet Med Assoc 193:1308-1316, 1988 3. Wilkie BN, Shewen PE: Bovine pneumonic pasteurellosis: A biotechnological approach to control. Proc 21 st Ann Conf, Am Assoc Bov Pract, Calgary (Sep 28 - Oct 1, 1988) 21:52-55, 1989 4. Confer AW, Wright JC, Cummins JM, et al: Use of a Huorometric immunoassay to determine antibody response to Pasteurella haemolytica in vaccinated and nonvaccinated feedlot cattle. J Clin Microbiol 18:866-871, 1983 5. Purdy CW, Livingston CW Jr, Frank GH, et al: A live Pasteurella haemolytica vaccine efficacy trial. J Am Vet Med Assoc 188:589-591, 1986 6. Henry CW: Shipping fever pneumonia. A new look at an old enemy. Vet Med 79:1200-1206, 1984 7. Smith RA, Gill DR, Hicks RB: Improving the performance of stocker and feedlot calves with a live Pasteurella haemolytica vaccine. Vet MedjSAC 81:978-981, 1986 8. Smith CK, Davidson IN, Henry CW: Evaluating a live vaccine for Pasteurella haemolytica in calves. Vet Med 80:78-88, 1985
BOVINE REPRODUCTIVE DISEASE VACCINES* Brucella abortus Vaccine
Brucella abortus causes abortions and subsequent retained placenta, metritis, and infertility in cows and heifers and, occasionally, (1) orchitis and epididymitis or (2) seminovesiculitis and ampullitis in bulls. It is recommended that all heifer calves that will be retained in the breeding herd be vaccinated for brucellosis. General recommendations for use of B. abortus vaccine are summarized (see Table 6). The present vaccine utilizes strain 19 modified-live B. abortus bacteria, administered by subcutaneous injection in reduced dosage. This vaccine can be legally administered only by accredited veterinarians, in accordance with regulations issued by the states within which it is being used. Its *IBR, BVD, and H. somnus vaccines and vaccination programs were discussed in the section Bovine Respiratory Disease Vaccines.
12. 13. 14. 15. 16. 17. 18. 19. 20. 21.
22.
CHARLES
A.
HJERPE'
mortality in feedlot calves: The Bruce County beef project, year two. Can J Comp Med 45:103-112, 1981 Martin SW, Meek AH, Davis DG, et al: Factors associated with mortality and treatment costs in feedlot calves: The Bruce County beef project, years 1978, 1979, 1980. Can J Comp Med 46:341-349,1980 Amstutz HE, Horstman LA, Morter RL: Clinical evaluation of the efficacy of Haemophilus somnus and Pasteu.rella spp bacterins. Bov Pract 16:106-108, 1981 Morter RL, Amstutz HE, Crandell RA: Clinical evaluation of prophylactic regimens for bovine respiratory disease. Bov Pract 17:56-58, 1982 Morter RL, Amstutz HE: Evaluating the efficacy of a Haemophilus somnus bacterin in a controlled field trial. Bov Pract 18:82-83, 1983 Martin SW, Janzen ED, Willson P, et al: A field trial of pre shipment vaccination of calves. Can Vet J 25:145-147,1984 Ribble CS, Jim GK, Janzen ED: Efficacy of immunization of feedlot calves with a commercial Haemophilus somnus vaccine. Can J Vet Res 52:191-198, 1988 Davidson IN, Carpenter TE, Hjerpe CA: An example of an economic decision analysis approach to the problem of thromboembolic meningoencephalitis (TEME) in feedlot cattle. Cornell Vet 71:383-390, 1981 Miller RB, Lein DH, McEntee KE, et al: Haemophilus somnus infection of the reproductive tract: A review. J Am Vet Med Assoc 182:1390-1392, 1983 Chladek DW: Bovine abortion associated with Haemophilus somnus. Am J Vet Res 36:1041, 1975 Van Dreumel AA, Kierstead M: Abortion associated with Hemophilus somnus infection in a bovine fetus. Can Vet J 16:367 -370, 1975 Klavano GG: Observations of Hemophilus somnus infection as an agent producing reproductive diseases: Infertility and abortions. In Proc Ann Mtg Soc Theriogenol. pp 139-149, 1980
Pasteurella hemolytica Vaccines P. hemolytica, biotype A, serotype 1 and/or P. multocida infections of the lung are chiefly responsible for the clinical signs and pathologic lesions of bovine bronchopneumonia and fibrinous pneumonia. The etiology and pathogenesis of bronchopneumonia and fibrinous pneumonia are briefly discussed in the section concerning PI3 virus vaccines. P. hemolytica and P. multocida also cause endometritis, metritis, and occasionally septicemia, with or without accompanying bronchopneumonia and fibrinous pneumonia.
General Considerations Conventional formalin-inactivated, whole-cell, aluminum hydroxide - adsorbed P. hemolytica and P. multocida bacterins have been utilized for more than a half-century. In general, they have been found to be ineffective immunizing agents.1 During the past 5 years, a total of six new P. hemolytica vaccines have been introduced in the United States. Four of these new P. hemolytica vaccines utilize modified-live bacterial agents. The two new inactivated P. hemolytica products are subunit vaccines (see Table 5). The immune mechanisms involved in resistance of the bovine lung to P. hemolytica infections are incompletely understood. It is clear, however, that resistance is greatly enhanced by the presence of serum and bronchoalveolar antibodies to (1) the leukotoxin of P. hemolytica
BOVINE VACCINES AND HERD V ACCINA TION PROGRAMS
211
and (2) certain surface antigens that are present in the bacterial capsule of P. hemolytica AI.2 Leukotoxin is an exotoxin produced by all serotypes of rapidly growing P. hemolytica. It is highly toxic to ruminant alveolar macrophages and neutrophils, which constitute some of the first lines of defense against invading bacteria. It is believed that vaccines that produce antibodies to both (I) leukotoxin and (2) bacterial capsular antigens (in a saline extract of logarithmic-phase P. hemolytica, referred to as carbohydrate protein subunit) are more effective than those that stimulate production of only one of these two types of antibodies. 2 It has been shown that effective live P. hemolytica vaccines stimulate high levels of both kinds of antibodies. 2 P. hemolytica bacterins in oil adjuvants stimulate high antibody titers to carbohydrate protein subunit but not to leukotoxin. 2 Conventional aluminum hydroxide - adsorbed P. hemolytica bacterins also do not stimulate leukotoxin antibody production and stimulate only low titers to carbohydrate protein subunit. 2 Subunit vaccines can be produced that stimulate high levels of leukotoxin-neutralizing antibodies and/or carbohydrate protein subunit antibodies, depending on the extraction process utilized. 2 Vaccines that utilize modified-live P. hemolytica bacteria will not be effective when administered within 7 days after or 3 days before systemic administration of antimicrobial agents. These same vaccines should probably not be administered simultaneously with MLV BVD vaccines, Brucella abortus vaccine, anthrax vaccine, or modified-live anaplasmosis vaccine. Only one modified-live P. hemolytica vaccine is specifically recommended by the manufacturer for administration to cattle arriving in feedlots (Respirvac, Beecham Laboratories, Bristol, TN 37620). Three of the new modified-live P. hemolytica vaccines are one-dose vaccines. Both new P. hemolytica subunit vaccines and one new modified-live P. hemolytica vaccine (Pneumo-Guard H, Norden Laboratories, Lincoln, NE 68521) are two-dose vaccines (see Table 5). General recommendations for use of P. hemolytica vaccines are summarized (see Table 5). Additional information and considerations concerning use of each of the six new P. hemolytica vaccines are discussed below. Respirvac (Beecham Laboratories, Bristol, TN 37620) This is a modified-live bacterial vaccine that is recommended for subcutaneous administration in a single dose to cattle not less than 3 months of age. Immunity develops within 14 days following administration. Annual booster vaccination is recommended. The manufacturer indicates that this vaccine causes no local or systemic reactions and is safe for administration to stressed cattle and to cattle arriving in feedlots. Additional claims are for a reduction of 90% in the extent of P. hemolytica bronchopneumonia and fibrinous pneumonia lesions and for reduced morbidity rates and mortality rates and improved response to treatment in feedlot cattle.
212
CHARLES
A.
HJERPE
Presponse (Langford, Guelph, Ontario, Canada N1K 1E4) This is an inactivated subunit vaccine. The manufacturer recommends that two doses be administered by intramuscular injection, 14 to 28 days apart, to cattle of any age. Annual booster vaccination is recommended. The manufacturer indicates that this vaccine causes no local or systemic reactions and is safe for administration to stressed cattle and cattle arriving in feedlots. In a large feedlot trial involving 2072 cattle, this vaccine was administered once on the day of arrival and again 1 to 5 days later. 3 In comparison with unvaccinated controls, the overall mortality rate was reduced by 49%, retreatments were reduced by 12% and treatment days were reduced by 8.2%. The morbidity rate was not significantly affected. The manufacturer claims that this vaccine stimulates both leukotoxin-neutralizing antibodies and serotype-specific agglutinating antibodies to bacterial surface antigens. Shipguard (Coopers Animal Health, Kansas City, KS 66103) This is a modified-live bacterial vaccine recommended for singledose subcutaneous or intramuscular administration, to cattle weighing not less than 400 lb (181 kg). Annual booster vaccination is recommended. Immunity develops within 14 to 21 days after administration. A systemic, febrile reaction and stiffness or lameness develops following vaccination in some animals. The manufacturer warns against simultaneous administration with Brucella abortus vaccine. Pneumo-Guard H (Norden Laboratories, Lincoln, NE 68521) This is a modified-live bacterial vaccine recommended for intramuscular administration, twice, at a 28-day interval, in the rear quarter of cattle weighing not less than 400 lb (181 kg). Annual booster vaccination is recommended. The manufacturer indicates that, although systemic reactions do not occur, approximately 4% of vaccinated animals show stiffness or lameness and that abscesses occur in less than 1 % of vaccinates. This vaccine is not recommended by the manufacturer for use in stressed cattle. Ninety-four per cent efficacy against experimental challenge with P. hemolytica is claimed. Septimune PH-K (Fort Dodge Laboratories, Fort Dodge, IA 50501) This is an inactivated subunit vaccine that is recommended for intramuscular administration in two doses, 14 to 28 days apart, to cattle of any age. Immunity is achieved by 14 days following administration of the second dose. Annual booster vaccination is recommended. Calves vaccinated prior to 6 months of age should be revaccinated when they are 6 months old. The manufacturer indicates that this vaccine does not cause systemic or local reactions, is safe for administration to stressed cattle, and is recommended for administration to cattle arriving in feedlots. The manufacturer claims that this vaccine contains a high concentration of specific bacterial capsular surface antigens. It does not induce antibodies to leukotoxin.
BOVINE VACCINES AND HERD VACCINATION PROGRAMS
213
Precon-PH (AH Robins, Richmond, VA 23220) This is a modified-live bacterial vaccine recommended for intradermal administration in a single dose to cattle of any age. Immunity develops within 7 to 10 days after vaccination. Booster vaccination is recommended at 6-month intervals. Local reactions may occur at the injection site. The vaccine is not recommended by the manufacturer for use in stressed or recently shipped cattle. A 25 to 40% reduction in the morbidity rate from pneumonia is claimed in animals vaccinated 7 to 10 days before shipping. In field vaccination trials, results have been mixed. In two studies in which cattle were vaccinated with Precon-PH 2 weeks before shipping to feedlots 4.5 and in a third study in which calves were vaccinated upon arrival in a feedlot, 6 morbidity and mortality rates were not significantly affected. In two other trials involving vaccination of calves (1) 2 weeks before shipment to an experiment station and (2) upon arrival in a feedlot, reduced morbidity rates were demonstrated in both cases and a reduced mortality rate was achieved in cattle vaccinated prior to shipment. 7 In a sixth field trial involving young dairy calves, reduced morbidity and mortality rates were obtained during the first month after vaccination. 8 These results were then reversed during the subsequent month (Davidson IN; unpublished data, 1985), so that the net result, by the time the calves were sold, was equivocal. In studies performed at Oklahoma State University, vaccination of cattle with Precon-PH did not stimulate production of the levels of whole-cell agglutinating antibodies that are usually associated with satisfactory immunity.4 All six of these vaccines are relatively new products. It is still too early to predict with certainty which, if any, will stand the test of time and which will fall by the wayside. Since Septimune PH-K does not produce leukotoxin-neutralizing antibodies, it would not be surprising if it proved to be less efficacious than at least some others. Some (if not all) modified-live P. hemolytica vaccines may prove to be excessively stressful for use in feedlot cattle (as well as in other high-stress situations). The time and skill required for successfully performing large numbers of intradermal injections has been a deterrent to widespread acceptance of Precon-PH. Because of the stress that is likely to be associated with administration of the modified-live P. hemolytica vaccines and because the inactivated subunit vaccines require a minimum of 3 weeks to develop effective immunity, it is likely that these new vaccines will find their greatest value and application in beef preweaning and preconditioning programs and on dairy farms and dairy calfraising facilities. In these programs, animals can be immunized at times when they are being subjected to minimal stresses, well before weaning and/or shipping or grouping. It should also be kept in mind that, on some farms and in some situations, pneumonia caused by P. multocida may be more of a problem than P. hemolytica pneumonia. Highly effective control of the pasteurella pneumonia problem will require development of safe and effective vaccine products for both P. hemolytica and P. multocida bacteria.
214
CHARLES
A.
HJERPE
P. multocida Va~cines The P. multocida vaccines presently available are conventional formalin-inactivated, whole-cell, aluminum hydroxide - adsorbed bacterins, which are not considered to be efficacious. The immune mechanisms involved in resistance of the bovine lung to P. multocida infections are poorly understood at present.
REFERENCES 1. Martin SW: Vaccination: Is it effective in preventing respiratory disease or influencing weight gains in feedlot calves? Can Vet J 24:10-19, 1983 2. Confer AW, Panciera RJ, Mosier DA: Bovine pneumonic pasteurellosis: Immunity to Pasteurella haemolytica. J Am Vet Med Assoc 193:1308-1316, 1988 3. Wilkie BN, Shewen PE: Bovine pneumonic pasteurellosis: A biotechnological approach to control. Proc 21 st Ann Conf, Am Assoc Bov Pract, Calgary (Sep 28 - Oct 1, 1988) 21:52-55, 1989 4. Confer AW, Wright JC, Cummins JM, et al: Use of a Huorometric immunoassay to determine antibody response to Pasteurella haemolytica in vaccinated and nonvaccinated feedlot cattle. J Clin Microbiol 18:866-871, 1983 5. Purdy CW, Livingston CW Jr, Frank GH, et al: A live Pasteurella haemolytica vaccine efficacy trial. J Am Vet Med Assoc 188:589-591, 1986 6. Henry CW: Shipping fever pneumonia. A new look at an old enemy. Vet Med 79:1200-1206, 1984 7. Smith RA, Gill DR, Hicks RB: Improving the performance of stocker and feedlot calves with a live Pasteurella haemolytica vaccine. Vet MedjSAC 81:978-981, 1986 8. Smith CK, Davidson IN, Henry CW: Evaluating a live vaccine for Pasteurella haemolytica in calves. Vet Med 80:78-88, 1985
BOVINE REPRODUCTIVE DISEASE VACCINES* Brucella abortus Vaccine
Brucella abortus causes abortions and subsequent retained placenta, metritis, and infertility in cows and heifers and, occasionally, (1) orchitis and epididymitis or (2) seminovesiculitis and ampullitis in bulls. It is recommended that all heifer calves that will be retained in the breeding herd be vaccinated for brucellosis. General recommendations for use of B. abortus vaccine are summarized (see Table 6). The present vaccine utilizes strain 19 modified-live B. abortus bacteria, administered by subcutaneous injection in reduced dosage. This vaccine can be legally administered only by accredited veterinarians, in accordance with regulations issued by the states within which it is being used. Its *IBR, BVD, and H. somnus vaccines and vaccination programs were discussed in the section Bovine Respiratory Disease Vaccines.