What is the recommended route of administration for the inactivated Japanese Encephalitis (JE) vaccine in adults and children?

Route of Administration for Inactivated Japanese Encephalitis Vaccine

The inactivated Japanese encephalitis vaccine (JE-VC) must be administered intramuscularly (IM), not subcutaneously, for all age groups. 1

Age-Specific Dosing and Administration

Children 2-35 Months

• Route: Intramuscular (IM) 1
• Dose: 0.25 mL per injection 1
• Schedule: Two doses on days 0 and 28 1
• Site: Anterolateral thigh is preferred for infants and younger children 2

Children 3-17 Years

• Route: Intramuscular (IM) 1
• Dose: 0.5 mL per injection 1
• Schedule: Two doses on days 0 and 28 1
• Site: Deltoid muscle is preferred for older children 2

Adults 18-65 Years

• Route: Intramuscular (IM) 1
• Dose: 0.5 mL per injection 1
• Schedule: Two doses on days 0 and 7-28 (accelerated schedule available only for this age group) 1
• Site: Deltoid muscle 2

Adults >65 Years

• Route: Intramuscular (IM) 1
• Dose: 0.5 mL per injection 1
• Schedule: Two doses on days 0 and 28 1

Critical Distinction from Older Vaccine Formulations

This is a crucial difference from the discontinued mouse brain-derived vaccine (JE-MB), which was administered subcutaneously. 1 The older JE-MB used a subcutaneous route with three doses at 1.0 mL for adults (0.5 mL for children 1-3 years) on days 0,7, and 30. 1 Healthcare providers must not confuse these two vaccines, as the current JE-VC requires intramuscular administration. 1

Injection Technique

• Needle angle: 90 degrees for intramuscular injections 2
• Needle size for adults/adolescents: 1-1½ inch, 22-25 gauge for deltoid injection 2
• Needle size for infants: 7/8-1 inch, 22-25 gauge for anterolateral thigh 2
• Avoid buttock injection: Risk of sciatic nerve injury and decreased vaccine efficacy 2

Vaccine Preparation

• Shake the syringe well before administration to obtain a white, opaque, homogeneous suspension 1
• For the 0.25 mL dose in young children, expel and discard half the volume from the 0.5 mL prefilled syringe by pushing the plunger to the red line 1

Timing Before Travel

Complete the 2-dose series at least 1 week before potential JE virus exposure. 1 For the older subcutaneous vaccine, the last dose needed to be given at least 10 days before travel to ensure adequate immune response and access to medical care for potential delayed reactions. 1 While the current IM vaccine has a shorter minimum interval, completing vaccination well in advance remains prudent. 3

Concomitant Vaccine Administration

• JE-VC can be given simultaneously with hepatitis A vaccine and rabies vaccine without interference 1
• Use separate syringes and different anatomical sites (>1 inch apart if possible) 1