What are the side effects of rabies vaccine and rabies immunoglobulin (RIG)?

Side Effects of Rabies Vaccine and Immunoglobulin

Rabies vaccines and rabies immunoglobulin (RIG) generally cause mild and transient side effects, with serious adverse reactions being rare, making their benefits far outweigh the risks in post-exposure prophylaxis situations.

Rabies Vaccine Side Effects

Local Reactions

• Pain at injection site: Most common local reaction, reported in 21-77% of recipients 1
• Erythema (redness), swelling, and induration: Occur in 60-89.5% of HDCV recipients 1
• Local itching at the injection site 1

Systemic Reactions

• Mild systemic reactions occur in 6.8-55.6% of vaccine recipients 1, including:
  • Headache
  • Fever
  • Dizziness
  • Gastrointestinal symptoms (nausea, vomiting)
  • Muscle aches (myalgia)
  • Malaise

Hypersensitivity Reactions

• Systemic allergic reactions occur in approximately 11 per 10,000 vaccinees 1
• Type I immediate hypersensitivity (1 per 10,000): Usually occurs during primary vaccination 1
• Type III hypersensitivity reactions (9 per 10,000): More common with booster doses 1
• Serum sickness-like reactions: Occur in up to 6% of persons receiving booster doses 2
  • Characterized by onset 2-21 days post-booster
  • Symptoms include generalized urticaria, arthralgia, arthritis, angioedema, nausea, vomiting, fever, and malaise
  • Not life-threatening 2

Rare Neurological Reactions

• Rare cases of neurologic illness resembling Guillain-Barré syndrome have been reported but causality not established 1, 2
• Acute neurologic syndrome involving seizure activity has been reported in isolated cases 1
• Other central and peripheral nervous system disorders have been temporally associated with rabies vaccines 1

Rabies Immunoglobulin (RIG) Side Effects

Common Side Effects

• Local pain at injection site 1
• Low-grade fever 1

Rare Side Effects

• Although not reported specifically for RIG, the following have been reported with similar immune globulin products 1:
  • Angioneurotic edema
  • Nephrotic syndrome
  • Anaphylaxis
• These reactions are extremely rare, making a causal relationship difficult to establish 1

Special Populations

Children

• Side effects in children are generally similar to adults
• In children under 15 years, fever (21.2%), vomiting (2.4%), and coughing (2.1%) may be more common 3
• Overall, only about 7% of children experience mild to moderate clinical reactions 4

Pregnant Women

• Rabies vaccination during pregnancy has not shown increased risk of adverse outcomes 5
• Only about 15% of pregnant women report mild side effects such as myalgia, malaise, and local reactions 5
• No evidence of increased congenital malformations has been observed 5

Management of Adverse Reactions

Key Principles

• Once initiated, rabies prophylaxis should not be interrupted or discontinued because of local or mild systemic adverse reactions 1
• Most reactions can be successfully managed with anti-inflammatory, antihistaminic, and antipyretic agents 1

For Patients with History of Hypersensitivity

• Pretreatment with antihistamines may be considered 1
• Epinephrine should be readily available to counteract anaphylactic reactions 1
• Close observation immediately after vaccination is recommended 1

Important Considerations

Immunosuppression

• Corticosteroids and other immunosuppressive agents can interfere with the development of active immunity 1
• Immunosuppressed patients should have their antibody titers checked after vaccination 1

Pregnancy

• Pregnancy is not a contraindication for rabies post-exposure prophylaxis 1
• The potential consequences of inadequately managed rabies exposure outweigh theoretical risks to the fetus 1

Reporting Adverse Events

• All serious systemic, neuroparalytic, or anaphylactic reactions should be reported to the Vaccine Adverse Event Reporting System (VAERS) 1

Conclusion

While side effects from rabies vaccines and immunoglobulin do occur, they are generally mild and self-limiting. Serious adverse reactions are rare, and the benefits of rabies prophylaxis far outweigh the risks, especially considering that rabies is nearly 100% fatal once symptoms develop.