CLINICAL PHARMACOLOGY
The occurrence of tetanus in the United States has decreased dramatically from
560 reported cases in 1947, when national reporting began, to a record low of
48 reported cases in 1987.1 The decline has resulted from widespread
use of tetanus toxoid and improved wound management, including use of tetanus
prophylaxis in emergency rooms.2
BayTet (tetanus immune globulin (human) solvent/detergent treated 250 units) supplies passive immunity to those individuals who have low or no immunity
to the toxin produced by the tetanus organism, Clostridium tetani. The
antibodies act to neutralize the free form of the powerful exotoxin produced
by this bacterium. Historically, such passive protection was provided by antitoxin
derived from equine or bovine serum; however, the foreign protein in these heterologous
products often produced severe allergic manifestations, even in individuals
who demonstrated negative skin and/or conjunctival tests prior to administration.
Estimates of the frequency of these foreign protein reactions following antitoxin
of equine origin varied from 5%–30%.3-6 If passive immunization is
needed, human tetanus immune globulin (TIG) is the product of choice. It provides
protection longer than antitoxin of animal origin and causes few adverse reactions.2
Several studies suggest the value of human tetanus antitoxin in the treatment
of active tetanus.7,8 In 1961 and 1962, Nation et al,7
using Hyper-Tet treated 20 patients with tetanus using single doses of 3,000
to 6,000 antitoxin units in combination with other accepted clinical and nursing
procedures. Six patients, all over 45 years of age, died of causes other than
tetanus. The authors felt that the mortality rate (30%) compared favorably with
their previous experience using equine antitoxin in larger doses and that the
results were much better than the 60% national death rate for tetanus reported
from 1951 to 1954.9 Blake et al,10 however, found in a
data analysis of 545 cases of tetanus reported to the Centers for Disease Control
from 1965 to 1971 that survival was no better with 8,000 units of TIG than with
500 units; however, an optimal dose could not be determined.
Serologic tests indicate that naturally acquired immunity to tetanus toxin
does not occur in the United States. Thus, universal primary vaccination, with
subsequent maintenance of adequate antitoxin levels by means of appropriately
timed boosters, is necessary to protect persons among all age groups. Tetanus
toxoid is a highly effective antigen; a completed primary series generally induces
protective levels of serum antitoxin that persist for ≥ 10 years.2
Passive immunization with BayTet (tetanus immune globulin (human) solvent/detergent treated 250 units) may be undertaken concomitantly with active
immunization using tetanus toxoid in those persons who must receive an immediate
injection of tetanus antitoxin and in whom it is desirable to begin the process
of active immunization. Based on the work of Rubbo,11 McComb and
Dwyer,12 and Levine et al,13 the physician may thus supply
immediate passive protection against tetanus, and at the same time begin formation
of active immunization in the injured individual which upon completion of a
full toxoid series will preclude future need for antitoxin.
Peak blood levels of IgG are obtained approximately 2 days after intramuscular
injection. The half-life of IgG in the circulation of individuals with normal
IgG levels is approximately 23 days.14
In a clinical study in eight healthy human adults receiving another hyperimmune
immune globulin product treated with solvent/detergent, Rabies Immune Globulin
(Human), BayRab®, prepared by the same manufacturing process, detectable
passive antibody titers were observed in the serum of all subjects by 24 hours
post injection and persisted through the 21 day study period. These results
suggest that passive immunization with immune globulin products is not affected
by the solvent/detergent treatment.
REFERENCES
1. Tetanus — United States, 1987 and 1988, MMWR 39(3): 37-41, 1990.
2. Diphtheria, Tetanus, and Pertussis: Recommendations for Vaccine Use and
Other Preventive Measures. Recommendations of the Immunization Practices Advisory
Committee (ACIP). MMWR 40 (RR-10): 1-28, 1991.
3. Moynihan NH: Tetanus prophylaxis and serum sensitivity tests. Br Med
J 1:260-4, 1956.
4. Scheibel I: The uses and results of active tetanus immunization. Bull
WHO 13:381-94, 1955.
5. Edsall G: Specific prophylaxis of tetanus. JAMA 171(4):417-27, 1959.
6. Bardenwerper HW: Serum neuritis from tetanus antitoxin. JAMA 179(10):763-6,
1962.
7. Nation NS, Pierce NF, Adler SJ, et al: Tetanus: the use of human hyperimmune
globulin in treatment. Calif Med 98(6):305-6, 1963.
8. Ellis M: Human antitetanus serum in the treatment of tetanus. Br Med
J 1(5338):1123-6, 1963.
9. Axnick NW, Alexander ER: Tetanus in the United States: A review of the problem.
Am J Public Health 47(12):1493-1501, 1957.
10. Blake PA, Feldman RA, Buchanan TM, et al: Serologic therapy of tetanus
in the United States, 1965-1971. JAMA 235(1):42-4, 1976.
11. Rubbo SD: New approaches to tetanus prophylaxis. Lancet 2(7461):449-53,
1966.
12. McComb JA, Dwyer RC: Passive-active immunization with tetanus immune globulin
(human). N Engl J Med 268(16):857-62, 1963.
13. Levine L, McComb JA, Dwyer RC, et al: Active-passive tetanus immunization;
choice of toxoid, dose of tetanus immune globulin and timing of injections.
N Engl J Med 274(4):186-90, 1966.
14. Waldmann TA, Strober W, Blaese RM: Variations in the metabolism of immunoglobulins
measured by turnover rates. In Merler E (ed.): Immunoglobulins: biologic aspects
and clinical uses. Washington, DC, Nat Acad Sci, 1970, p. 33-51.