What are the management steps for influenza vaccine reactions?

Management of Influenza Vaccine Reactions

The management of influenza vaccine reactions should follow a structured approach based on the severity and type of reaction, with immediate recognition and treatment of anaphylaxis being the highest priority.

Types of Influenza Vaccine Reactions

Local Reactions

• Soreness at the vaccination site lasting up to 2 days (reported in less than one-third of vaccinees) 1
• Redness and swelling at the injection site 1

Systemic Reactions

1. Mild to Moderate Reactions:

   • Fever, malaise, myalgia occurring 6-12 hours after vaccination
   • Most common in those with no prior exposure to influenza virus antigens (e.g., young children)
   • Usually persist for 1-2 days 1

2. Severe Allergic Reactions:

   • Immediate allergic reactions (hives, angioedema, allergic asthma, systemic anaphylaxis)
   • Typically occur within minutes of vaccination
   • Estimated incidence of anaphylaxis is 1.31 per million vaccine doses 2
   • Most commonly related to residual egg protein or other vaccine components 1

Management Algorithm for Influenza Vaccine Reactions

For Local Reactions:

• Apply cold compress to reduce pain and swelling
• Use over-the-counter analgesics (acetaminophen or NSAIDs) if needed for pain
• Reassure patient that these reactions are common and self-limiting

For Mild Systemic Reactions:

• Recommend rest and adequate hydration
• Use antipyretics/analgesics for fever and discomfort
• Monitor symptoms; should resolve within 1-2 days

For Severe Allergic Reactions:

1. Immediate Actions for Anaphylaxis:

   • Administer epinephrine (1:1000) intramuscularly in the mid-anterolateral thigh
   • Place patient in supine position with legs elevated (unless respiratory distress)
   • Monitor vital signs
   • Establish IV access if possible
   • Administer oxygen if available

2. Secondary Interventions:

   • Antihistamines (H1 and H2 blockers) for urticaria/angioedema
   • Corticosteroids to prevent biphasic reactions
   • Bronchodilators for bronchospasm
   • IV fluids for hypotension

3. Monitoring and Follow-up:

   • Monitor patient for at least 4-6 hours after initial response
   • Consider hospital admission for severe reactions
   • Refer to allergist for evaluation before future vaccinations

Prevention of Reactions in High-Risk Individuals

For Persons with Egg Allergy:

• Persons with history of only urticaria after egg exposure can receive any age-appropriate influenza vaccine 1
• Persons with symptoms beyond urticaria (angioedema, respiratory distress, lightheadedness, recurrent vomiting) can still receive any appropriate influenza vaccine, but:
  • If using egg-based vaccines, administer in medical setting with supervision by healthcare provider able to recognize and manage severe allergic reactions
  • Consider cell culture-based (ccIIV4) or recombinant (RIV4) influenza vaccines which are egg-free 1

For Persons with Previous Vaccine Reactions:

• For those with history of severe allergic reaction to any influenza vaccine:
  • Consider alternative vaccine types based on the specific reaction history
  • If ccIIV4 or RIV4 is administered to someone with history of reaction to other influenza vaccines, vaccination should occur in medical setting with appropriate supervision 1
  • Consider consultation with allergist to identify the responsible vaccine component 1

For Persons Who Cannot Receive Vaccine:

• Consider prophylactic use of antiviral agents (e.g., oseltamivir) for prevention of influenza, particularly in high-risk individuals 1

Important Considerations for Vaccination Providers

• All vaccination providers should be familiar with their office emergency plan
• Providers should be certified in cardiopulmonary resuscitation 1
• Appropriate emergency equipment and medications should be immediately available
• Consider observing all patients for 15 minutes after vaccination to decrease risk of injury should syncope occur 1

Special Situations

• For pregnant women: Influenza vaccination is recommended and has not been associated with increased adverse reactions compared to non-pregnant individuals
• For immunocompromised patients: Monitor more closely for reactions, but vaccination is generally recommended due to higher risk from influenza itself
• For travelers: Consider timing of vaccination at least 2 weeks before departure 1

By following this structured approach to managing influenza vaccine reactions, healthcare providers can effectively address adverse events while maintaining public confidence in vaccination programs.