Tetanus Toxoid Adsorbed

What is Tetanus Toxoid Adsorbed and how is it used?

Tetanus Toxoid Adsorbed is a vaccine used to prevent the symptoms of tetanus. Tetanus Toxoid Adsorbed may be used alone or with other medications.

Tetanus Toxoid Adsorbed belongs to a class of drugs called Vaccines, Inactivated, Bacterial.

It is not known if Tetanus Toxoid Adsorbed is safe and effective in children younger than 7 years of age.

What are the possible side effects of Tetanus Toxoid Adsorbed?

Tetanus Toxoid Adsorbed may cause serious side effects including:

• extreme drowsiness,
• fainting,
• severe headache,
• vomiting,
• fussiness,
• irritability,
• crying for an hour or longer,
• confusion,
• convulsions (seizure), and
• high fever

Get medical help right away, if you have any of the symptoms listed above.

The most common side effects of Tetanus Toxoid Adsorbed include:

• redness, pain, tenderness, swelling, or a hard lump where the shot was given,
• mild fever,
• mild fussiness,
• crying,
• joint pain,
• body aches,
• mild drowsiness, and
• mild vomiting

Tell the doctor if you have any side effect that bothers you or that does not go away.

These are not all the possible side effects of Tetanus Toxoid Adsorbed. For more information, ask your doctor or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

DESCRIPTION

Tetanus Toxoid Adsorbed USP, for intramuscular use, is a sterile suspension of alum-precipitated (aluminum potassium sulfate) toxoid in an isotonic sodium chloride solution containing sodium phosphate buffer to control pH. The vaccine, after shaking, is a turbid liquid, whitish-gray in color.

Clostridium tetani culture is grown in a peptone-based medium and detoxified with formaldehyde. The detoxified material is then purified by serial ammonium sulfate fractionation, followed by sterile filtration, and the toxoid is adsorbed to aluminum potassium sulfate (alum). The adsorbed toxoid is diluted with physiological saline solution (0.85%) and thimerosal (a mercury derivative) is added to a final concentration of 1:10,000.

Each 0.5 mL dose is formulated to contain 5 Lf (flocculation units) of tetanus toxoid and not more than 0.25 mg of aluminum. The residual formaldehyde content, by assay, is less than 0.02%. The tetanus toxoid induces at least 2 units of antitoxin per mL in the guinea pig potency test.

INDICATIONS

Tetanus Toxoid Adsorbed vaccine is indicated for active immunization of children 7 years of age or older, and adults, against tetanus, wherever combined antigen preparations are not indicated.¹

This vaccine should not be used for immunizing children below 7 years of age. In children below 7 years of age, either Diphtheria and Tetanus Toxoids and Acellular Pertussis Vaccine Adsorbed (DTaP) - Tripedia®, or Diphtheria and Tetanus Toxoids and Pertussis Vaccine Adsorbed USP (For Pediatric Use) (DTP) is recommended. If a contraindication to pertussis immunization exists, the recommended vaccine is Diphtheria and Tetanus Toxoids Adsorbed (For Pediatric Use) (DT).¹

For the prevention of neonatal tetanus in infants born of unvaccinated pregnant women, see Pregnancy section.¹

This vaccine is NOT to be used for the treatment of tetanus infection.

As with any vaccine, vaccination with Tetanus Toxoid Adsorbed may not protect 100% of susceptible individuals.

If passive immunization is required, Tetanus Immune Globulin (Human) (TIG) should be used (see DRUG INTERACTIONS and DOSAGE AND ADMINISTRATION sections).

DOSAGE AND ADMINISTRATION

Parenteral drug products should be inspected visually for extraneous particulate matter and/or discoloration prior to administration whenever solution and container permit. If these conditions exist, the vaccine should not be administered.

SHAKE VIAL WELL before withdrawing each dose. Discard vial of vaccine if it cannot be resuspended.

Inject intramuscularly in the area of the vastus lateralis (mid-thigh laterally) or deltoid. The vaccine should not be injected into the gluteal area or areas where there may be a major nerve trunk.

The following guidelines are derived from the Advisory Committee on Immunization Practices (ACIP).¹

Primary Immunization for Persons 7 Years of Age and Older

A series of three doses of 0.5 mL each, of Tetanus Toxoid Adsorbed vaccine should be given intramuscularly; the second dose of 0.5 mL is given 4 to 8 weeks after the first dose; and the third dose of 0.5 mL is given 6 to 12 months after the second dose.

Children who remain incompletely immunized after their seventh birthday should be counted as having prior exposure to tetanus and diphtheria toxoids (e.g., a child who previously received two doses of DTaP or DTP needs only one dose of Tetanus Toxoid Adsorbed vaccine to complete the primary series for tetanus).

Interruption of the recommended schedule with a delay between doses does not interfere with the final immunity achieved with Tetanus Toxoid Adsorbed vaccine. There is no need to start the series over again, regardless of the time elapsed between doses.

Routine Booster Injections

To maintain adequate protection, a booster dose of 0.5 mL of Td (For Adult Use) vaccine or Tetanus Toxoid Adsorbed vaccine every 10 years thereafter is recommended.

Booster Injection After Injury

A thorough attempt must be made to determine whether a patient has completed primary immunization. Patients with unknown or uncertain previous immunization histories should be considered to have no previous tetanus toxoid doses. Persons who had military service since 1941 can be considered to have received at least one dose. Although most people in the military since 1941 may have completed a primary series of tetanus toxoid, this cannot be assumed for each individual. Patients who have not completed a primary series may require tetanus toxoid and passive immunization at the time of wound cleaning and debridement (Table 1).¹

Available evidence indicates that complete primary vaccination with tetanus toxoid provides long-lasting protection ≥ 10 years for most recipients. Consequently, after complete primary tetanus vaccination, boosters, even for wound management, need to be given only every 10 years when wounds are minor and uncontaminated. For other wounds, a booster is appropriate if the patient has not received tetanus toxoid within the preceding five years. Persons who have received at least two doses of tetanus toxoid develop antitoxin antibodies.¹

Tetanus and Diphtheria Toxoids Adsorbed For Adult Use (Td) is the preferred vaccine for active tetanus immunization in wound management of patients ≥ 7 years of age. Because a large proportion of adults are susceptible to diphtheria, this vaccine enhances diphtheria protection. Thus, by taking advantage of acute health-care visits, such as for wound management, some patients can be protected who otherwise would remain susceptible. For inadequately vaccinated patients of all ages, completion of primary vaccination at the time of discharge or at follow-up visits should be ensured.¹

TABLE 1¹: Guide to Tetanus Prophylaxis in Routine Wound Management*

History of Adsorbed Tetanus Toxoid (Doses)	Clean, Minor Wounds		All Other Wounds**
	Td	TIG	Td	TIG
Unknown or < three	Yes	No	Yes	Yes
≥ Three	No†	No	No§	No
* Important details are in the text of the insert. **Such as, but not limited to, wounds contaminated with dirt, feces, soil, and saliva; puncture wounds; avulsions; and wounds resulting from missiles, crushing, burns, and frostbite. † Yes, if > 10 years since last dose. §Yes, if > 5 years since last dose. (More frequent boosters are not needed and can accentuate side effects.)

If passive immunization for tetanus is needed, TIG (Human) is the product of choice. It provides longer protection than antitoxin of animal origin and causes few adverse reactions. The currently recommended prophylactic dose of TIG (Human) for wounds of average severity is 250 units intramuscularly. When tetanus toxoid and TIG (Human) are given concurrently, separate syringes and separate sites should be used. The ACIP recommends the use of only adsorbed toxoid in this situation.¹

HOW SUPPLIED

Vial, 5 mL – Product No. 49281-800-83

Storage

Store between 2° – 8°C (35° – 46°F). DO NOT FREEZE.

REFERENCES

1. Recommendations of the Immunization Practices Advisory Committee (ACIP). Diphtheria, Tetanus, and Pertussis: Recommendations for vaccine use and other preventive measures. MMWR 40: No. RR-10, 1991

Manufactured by: Aventis Pasteur Inc. Swiftwater PA 18370 USA Product information as of April 1999. FDA Rev date: n/a

SIDE EFFECTS

Body System As a Whole

Adverse reactions may be local and include redness, warmth, edema, induration with or without tenderness as well as urticaria, and rash. Malaise, transient fever, pain, hypotension, nausea and arthralgia may develop in some patients after the injection. Arthus-type hypersensitivity reactions, characterized by severe local reactions (generally starting 2 to 8 hours after an injection) may occur, particularly in persons who have received multiple prior boosters.¹

Rarely, an anaphylactic reaction (i.e., hives, swelling of the mouth, difficulty breathing, hypotension, or shock) and death have been reported after receiving preparations containing tetanus and diphtheria antigens.

Deaths have been reported in temporal association with the administration of tetanus toxoid containing vaccines. On rare occasion, anaphylaxis has been reported following administration of products containing tetanus toxoid. Upon review, a report by the Institute of Medicine (IOM) concluded the evidence established a causal relationship between tetanus toxoid and anaphylaxis.⁶

Nervous System

The following neurologic illnesses have been reported as temporally associated with vaccine containing tetanus toxoid: neurological complications¹³ including cochlear lesion,¹⁴ brachial plexus neuropathies,^14,15 paralysis of the radial nerve,¹⁶ paralysis of the recurrent nerve,¹⁴ accommodation paresis, Guillain-Barré syndrome (GBS) and EEG disturbances with encephalopathy. The IOM following review of the reports of neurologic events following vaccination with tetanus toxoid, Td or DT, concluded the evidence favored acceptance of a causal relationship between tetanus toxoid and brachial neuritis and GBS.^6,17

EPINEPHRINE INJECTION (1:1000) MUST BE IMMEDIATELY AVAILABLE SHOULD AN ACUTE ANAPHYLACTIC REACTION OCCUR DUE TO ANY COMPONENT OF THE VACCINE.

Reporting of Adverse Events

The National Vaccine Injury Compensation Program, established by the National Childhood Vaccine Injury Act of 1986, requires physicians and other health-care providers who administer vaccines to maintain permanent vaccination records and to report occurrences of certain adverse events to the US Department of Health and Human Services. Reportable events include those listed in the Act for each vaccine and events specified in the package insert as contraindications to further doses of the vaccine.^9,10

Reporting by parents or guardians of all adverse events after vaccine administration should be encouraged. Adverse events following immunization with vaccine should be reported by health-care providers to the US Department of Health and Human Services (DHHS) Vaccine Adverse Event Reporting System (VAERS). Reporting forms and information about reporting requirements or completion of the form can be obtained from VAERS through a toll-free number 1-800-822-7967.^8,9,10

Health-care providers also should report these events to Director of Scientific and Medical Affairs, Aventis Pasteur Inc., Discovery Drive, Swiftwater, PA 18370 or call 1-800-822-2463.

DRUG INTERACTIONS

If passive immunization for tetanus is needed, TIG (Human) is the product of choice. It provides longer protection than antitoxin of animal origin and causes few adverse reactions. The currently recommended prophylactic dose of TIG (Human) for wounds of average severity is 250 units intramuscularly. When Tetanus Toxoid Adsorbed vaccine and TIG (Human) are given concurrently, separate syringes and separate sites should be used. The ACIP recommends the use of only adsorbed toxoid in this situation.¹

As with other intramuscular injections, use with caution in patients on anticoagulant therapy.

Immunosuppressive therapies may reduce the immune response to vaccines (see PRECAUTIONS – General section).

REFERENCES

1. Recommendations of the Immunization Practices Advisory Committee (ACIP). Diphtheria, Tetanus, and Pertussis: Recommendations for vaccine use and other preventive measures. MMWR 40: No. RR-10, 1991

6. Stratton KR, et al. Adverse events associated with childhood vaccines. Evidence Bearing on Causality. National Academy Press, Washington, DC, 1994

8. CDC. Vaccine Adverse Event Reporting System – United States. MMWR 39: 730-733, 1990

9. CDC. National Childhood Vaccine Injury Act: requirements for permanent vaccination records and for reporting of selected events after vaccination. MMWR 37: 197-200, 1988

10. Food and Drug Administration. New reporting requirements for vaccine adverse events. FDA Drug Bull 18 (2), 16-18, 1988

13. Rutledge SL, et al. Neurological complications of immunizations. J. Pediatr 109: 917-924, 1986

14. Wilson GS. The Hazards of Immunization. Allergic manifestations: post-vaccinal neuritis. pp 153-156, 1967

15. Tsairis P, et al. Natural history of brachial plexus neuropathy. Arch Neurol 27: 109-117, 1972

16. Blumstein GI, et al. Peripheral neuropathy following tetanus toxoid administration. JAMA 198: 1030-1031, 1966

17. Pollard JD, et al. Relapsing neuropathy due to tetanus toxoid: report of a case. J Neurol Sci 37: 112-125, 1978

WARNINGS

This product contains dry natural latex rubber as follows: The stopper to the vial contains dry natural latex rubber.

Persons who experienced Arthus-type hypersensitivity reactions or a temperature of > 103°F ( > 39.4°C) following a prior dose of tetanus toxoid usually have high serum tetanus antitoxin levels and should not be given even emergency doses of Tetanus Toxoid Adsorbed more frequently than every 10 years, even if they have a wound that is neither clean nor minor.¹

Intramuscular injections should be given with great care in patients suffering from thrombocytopenia or other coagulation disorders.

A routine booster should not be given more frequently than every ten years. (This guideline should not preclude wound management considerations.)

Deaths have been reported in temporal association with the administration of Tetanus Toxoid Adsorbed vaccine; however, no causal relationship was proven⁶ (see ADVERSE REACTIONS section).

PRECAUTIONS

General

Care is to be taken by the health-care provider for the safe and effective use of Tetanus Toxoid Adsorbed vaccine.

EPINEPHRINE INJECTION (1:1000) MUST BE IMMEDIATELY AVAILABLE SHOULD AN ACUTE ANAPHYLACTIC REACTION OCCUR DUE TO ANY COMPONENT OF THE VACCINE.

There is an increased incidence of local and systemic reactions to booster doses of tetanus toxoid when given to previously immunized persons. (Refer to DOSAGE AND ADMINISTRATION section for timing of booster injections.) Prior to an injection of any vaccine, all known precautions should be taken to prevent adverse reactions. This should include a review of the patient's history with respect to possible sensitivity and any previous adverse reactions (see CONTRAINDICATIONS section) to the vaccine or similar vaccines and to possible sensitivity to dry natural latex rubber, and a current knowledge of the literature concerning the use of the vaccine under consideration.

Special care should be taken to ensure that the injection does not enter a blood vessel.

Immunosuppressive therapies including radiation, corticosteroids, antimetabolites, alkylating agents, and cytotoxic drugs may reduce the immune response to vaccines. Therefore, routine vaccination should be deferred, if possible, while patients are receiving such therapy.¹ If Tetanus Toxoid Adsorbed vaccine has been administered to persons receiving immunosuppressive therapy, or having an immunodeficiency disorder, an adequate antibody response may not be obtained.¹ When possible, immunosuppressive treatment should be interrupted when immunization is required due to a tetanus-prone wound.

Administration of Tetanus Toxoid Adsorbed vaccine is not contraindicated in individuals with HIV infection.⁷

It is advisable to use DT (For Pediatric Use – under 7 years of age) or Td (For Adult Use – 7 years of age and older) in wound prophylaxis instead of tetanus toxoid alone in order to maintain adequate levels of diphtheria immunity.¹

A separate, sterile syringe and needle or a sterile disposable unit must be used for each patient to prevent transmission of hepatitis or other infectious agents from person to person. Needles should not be recapped and should be disposed of according to biohazard waste guidelines.

Carcinogenesis, Mutagenesis, Impairment of Fertility

No studies have been performed to evaluate carcinogenicity, mutagenic potential, or impact on fertility.

Pregnancy

Reproductive Studies – Pregnancy Category C

Animal reproduction studies have not been conducted with Tetanus Toxoid Adsorbed vaccine. It is also not known whether Tetanus Toxoid Adsorbed vaccine can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Tetanus Toxoid Adsorbed vaccine should be given to a pregnant woman only if clearly needed.

Adequate immunization by routine boosters in non-pregnant women of child-bearing age can obviate the need to vaccinate women during pregnancy (see DOSAGE AND ADMINISTRATION section).

Physicians generally avoid prescribing unnecessary drugs and biologics for pregnant women.

However, the ACIP recommends the following: A previously unvaccinated pregnant woman whose child might be born under unhygienic circumstances (without sterile technique) should receive two doses of Td 4 to 8 weeks apart before delivery, preferably during the last two trimesters. Pregnant women in similar circumstances who have not had a complete vaccination series should complete the three-dose series. Those vaccinated more than 10 years previously should have a booster dose. No evidence exists to indicate that tetanus and diphtheria toxoids administered during pregnancy are teratogenic.¹

It has been reported that tetanus toxoid administered to pregnant women prevents neonatal tetanus in newborns.^11,12 However, the data reported on the safety of tetanus toxoid when so used is inconclusive because the incidence of neonatal deaths in New Guinea was significantly higher than in the United States.¹¹ A prospective study in the United States has not been done to confirm these reports.

Pediatric Use

SAFETY AND EFFECTIVENESS OF TETANUS TOXOID ADSORBED VACCINE IN INFANTS BELOW THE AGE OF SIX WEEKS HAVE NOT BEEN ESTABLISHED. HOWEVER, THIS VACCINE IS NOT INDICATED FOR CHILDREN UNDER 7 YEARS OF AGE.

Tetanus Toxoid Adsorbed vaccine is suitable for tetanus immunization in the pediatric age group. However, for children under 7 years of age DT (For Pediatric Use) is preferred to tetanus toxoid alone if the pertussis component is contraindicated. For children 7 years of age and older, Td (For Adult Use) is preferred to tetanus toxoid alone.¹

REFERENCES

1. Recommendations of the Immunization Practices Advisory Committee (ACIP). Diphtheria, Tetanus, and Pertussis: Recommendations for vaccine use and other preventive measures. MMWR 40: No. RR-10, 1991

6. Stratton KR, et al. Adverse events associated with childhood vaccines. Evidence Bearing on Causality. National Academy Press, Washington, DC, 1994

7. ACIP. General recommendations on immunization. MMWR 38: 205-227, 1989

11. MacLennan R, et al. Immunization against neonatal tetanus in New Guinea. Antitoxin response of pregnant women to adjuvant and plain toxoids. Bull WHO 32: 683-697, 1965

12. Newell KW, et al. The use of toxoid for the prevention of tetanus neonatorium. Bull WHO 35: 863-871, 1966

OVERDOSE

No information provided.

CONTRAINDICATIONS

HYPERSENSITIVITY TO ANY COMPONENT OF THE VACCINE, INCLUDING THIMEROSAL, A MERCURY DERIVATIVE, IS A CONTRAINDICATION FOR FURTHER USE OF THIS VACCINE.

It is a contraindication to use this or any other related vaccine after a serious adverse reaction temporally associated with a previous dose, including an anaphylactic reaction.

A history of systemic allergic or neurologic reactions following a previous dose of Tetanus Toxoid Adsorbed vaccine is an absolute contraindication for further use.¹

If a contraindication to using tetanus toxoid-containing preparations exists in a person who has not completed a primary immunizing course of tetanus toxoid and other than a clean, minor wound is sustained, only passive immunization should be given using TIG (Human).¹

Immunization should be deferred during the course of any febrile illness or acute infection. A minor afebrile illness such as a mild upper respiratory infection should not preclude immunization.¹

Elective immunization procedures should be deferred during an outbreak of poliomyelitis.⁵

REFERENCES

1. Recommendations of the Immunization Practices Advisory Committee (ACIP). Diphtheria, Tetanus, and Pertussis: Recommendations for vaccine use and other preventive measures. MMWR 40: No. RR-10, 1991

5. Wilson GS. The Hazards of Immunization. Provocation poliomyelitis. 270-274, 1967

CLINICAL PHARMACOLOGY

Tetanus is an intoxication manifested primarily by neuromuscular dysfunction caused by a potent exotoxin elaborated by Clostridium tetani.

The occurrence of tetanus in the United States (US) has decreased dramatically from 560 reported cases in 1947 to a record low of 48 reported cases in 1987. Tetanus in the US is primarily a disease of older adults. Of 99 tetanus patients with complete information reported to the Centers for Disease Control and Prevention (CDC) during 1987 and 1988, 68% were ≥ 50 years of age, while only six were < 20 years of age. Overall, the case-fatality rate was 21%. The age distribution of recent cases and the results of serosurveys indicate that many US adults are not protected against tetanus. Serosurveys undertaken since 1977 indicate that 6% to 11% of adults 18 to 39 years of age and 49% to 66% of those ≥ 60 years of age may lack protective levels of circulating tetanus antitoxin.¹ In 1992, 45 cases were reported of which 82% were ≥ 50 years of age.² The disease continues to occur almost exclusively among persons who are unvaccinated or inadequately vaccinated or whose vaccination histories are unknown or uncertain.¹

In 4% of tetanus cases reported during 1987 and 1988, no wound or other condition was implicated. Non-acute skin lesions, such as ulcers, or medical conditions such as abscesses, were reported in association with 14% of cases.¹

Neonatal tetanus occurs among infants born under unhygienic conditions to inadequately vaccinated mothers. Vaccinated mothers confer protection to their infants through transplacental transfer of maternal antibody. From 1972 through 1984, 29 cases of neonatal tetanus were reported in the United States. No cases of neonatal tetanus were reported in the period 1985 to 1989.¹

Spores of C. tetani are ubiquitous. Serologic tests indicate that naturally acquired immunity to tetanus toxin does not occur in the US.¹ 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, and a completed primary series generally induces protective levels of neutralizing antibodies to tetanus toxin that persist for ≥ 10 years.¹

The efficacy of tetanus toxoid was determined on the basis of immunogenicity studies with a comparison to a serological correlate of protection (0.01 antitoxin units/mL) established by the Panel on Review of Bacterial Vaccines & Toxoids.³

Tetanus toxoid was administered to a previously unimmunized rural population 6 years of age and older. The primary immune response to tetanus toxoid in 46 persons had titers of 0.01 AU (antitoxin units) or more one month after the second and the third immunizations. The geometric mean titers at both nine and 61 weeks for children 6 to 18 years of age were significantly greater than for adults older than 18 years of age (P < .001).⁴

REFERENCES

1. Recommendations of the Immunization Practices Advisory Committee (ACIP). Diphtheria, Tetanus, and Pertussis: Recommendations for vaccine use and other preventive measures. MMWR 40: No. RR-10, 1991

2. Centers for Disease Control and Prevention (CDC), Summary of Notifiable Disease, United States 1992. MMWR 41: No. 55, 1993

3. Department of Health and Human Services, Food and Drug Administration. Biologicals Products; Bacterial Vaccines and Toxoids; Implementation of Efficacy Review; Proposed Rule. Federal Register Vol 50 No 240, pp 51002-51117, 1985

4. Myers G, et al. Primary Immunization with Tetanus and Diphtheria Toxoids. JAMA 248: 2478-2480, 1982

PATIENT INFORMATION

Prior to administration of Tetanus Toxoid Adsorbed vaccine, health-care personnel should inform the parent, guardian, or adult patient the benefits and risks of immunization, and also inquire about the recent health status of the patient to be injected.

The health-care provider should inform the parent, guardian, or adult patient about the potential for adverse reactions that have been temporally associated with Tetanus Toxoid Adsorbed administration. The parent, guardian or adult patient should be instructed to report any serious adverse reactions to their health-care provider.

As part of the child's or adult's permanent immunization record, the date, lot number and manufacturer of the vaccine administered MUST be recorded.^8,9,10

IT IS EXTREMELY IMPORTANT WHEN THE PARENT, GUARDIAN, OR ADULT PATIENT RETURNS FOR THE NEXT DOSE IN THE SERIES, THE PARENT, GUARDIAN, OR ADULT PATIENT SHOULD BE QUESTIONED CONCERNING OCCURRENCE OF ANY SYMPTOMS AND/OR SIGNS OF AN ADVERSE REACTION AFTER THE PREVIOUS DOSE (SEE CONTRAINDICATIONS; ADVERSE REACTIONS SECTIONS).

The health-care provider should inform the parent, guardian, or adult patient of the importance of completing the immunization series.

The health-care provider should provide the Vaccine Information Materials (VIMs) which are required to be given with each immunization.

REFERENCES

8. CDC. Vaccine Adverse Event Reporting System – United States. MMWR 39: 730-733, 1990

9. CDC. National Childhood Vaccine Injury Act: requirements for permanent vaccination records and for reporting of selected events after vaccination. MMWR 37: 197-200, 1988

10. Food and Drug Administration. New reporting requirements for vaccine adverse events. FDA Drug Bull 18 (2), 16-18, 1988