In very rare cases, neurological and neuroparalytical events have been reported in temporal association with administration of RabAvert® (see also WARNINGS section). These include cases of hypersensitivity (see CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS sections).
The most commonly occurring adverse reactions are injection site reactions, such as injection site erythema, induration and pain; flu-like symptoms, such as asthenia, fatigue, fever, headache, myalgia and malaise; arthralgia, dizziness, lymphadenopathy, nausea, and rash.
A patient's risk of acquiring rabies must be carefully considered before deciding to discontinue vaccination. Advice and assistance on the management of serious adverse reactions for persons receiving rabies vaccines may be sought from the state health department or CDC (see also CONTRAINDICATIONS section).
Local reactions such as induration, swelling and reddening have been reported more often than systemic reactions. In a comparative trial in normal volunteers, Dreesen et al. (4) described their experience with RabAvert® compared to a HDCV rabies vaccine. Nineteen subjects received RabAvert® and 20 received HDCV. The most commonly reported adverse reaction was pain at the injection site, reported in 45% of the HDCV group, and 34% of the RabAvert® group. Localized lymphadenopathy was reported in about 15% of each group. The most common systemic reactions were malaise (15 % RabAvert® group vs. 25 % HDCV group), headache (10 % RabAvert® group vs. 20 % HDCV group), and dizziness (15 % RabAvert® group vs. 10 % HDCV group). In a recent study in the USA (5), 83 subjects received RabAvert® and 82 received HDCV. Again, the most common adverse reaction was pain at the injection site in 80% in the HDCV group and 84% in the RabAvert® group. The most common systemic reactions were headache (52% RabAvert® group vs. 45% HDCV group), myalgia (53% RabAvert® group vs. 38% HDCV group) and malaise (20% RabAvert® group vs. 17% HDCV group). None of the
adverse events were serious, almost all adverse events were of mild or moderate intensity. Statistically significant differences between vaccination groups were not found. Both vaccines were generally well tolerated.
Uncommonly observed adverse events include temperatures above 38°C (100°F), swollen lymph nodes, pain in limbs and gastrointestinal complaints. In rare cases, patients have experienced severe headache, fatigue, circulatory reactions, sweating, chills, monoarthritis and allergic reactions; transient paresthesias and one case of suspected urticaria pigmentosa have also been reported.
OBSERVED DURING CLINICAL PRACTICE (SEE WARNINGS AND PRECAUTIONS)
The following adverse reactions have been identified during post approval use of RabAvert®. Because these reactions are reported voluntarily from a population of uncertain size, estimates of frequency cannot be made. These events have been chosen for inclusion due to their seriousness, frequency of reporting, causal connection to RabAvert®, or a combination of these factors:
Allergic: Anaphylaxis, Type III hypersensitivity-like reactions, bronchospasm, urticaria, pruritis, edema
CNS: Neuroparalysis, encephalitis, meningitis, transient paralysis, Guillain-Barre Syndrome, myelitis, retrobulbar neuritis, multiple sclerosis, vertigo, visual disturbance
Cardiac: Palpitations, hot flush
Local: Extensive limb swelling
The use of corticosteroids to treat life-threatening neuroparalytic reactions may inhibit the development of immunity to rabies (see PRECAUTIONS, Drug Interactions).
Once initiated, rabies prophylaxis should not be interrupted or discontinued because of local or mild systemic adverse reactions to rabies vaccine. Usually such reactions can be successfully managed with anti-inflammatory and antipyretic agents.
REPORTING OF ADVERSE EVENTS
Adverse events should be reported by the health care provider or patient to the US Department of Health and Human Services (DHHS) Vaccine Adverse Event Reporting System (VAERS). Report forms and information about reporting requirements or completion of the form can be obtained from VAERS by calling the toll-free number 1-800-822-7967 (1). In the USA, such events can be reported to the Professional Services department, Chiron Corporation: phone: 1-800-CHIRON-8.