Thank you for your query at DoctorSpring.com
I can understand your concerns.Such reactions with JE vaccine or any injection are common. After seeing needles or injections, children can have even brief fainting spells. Sitting or lying down for about 15 minutes after the vaccine can prevent such episodes. In fact, a child can have vaso-vagal fainting episodes after any painful or perceived painful procedure.
Any drug can produce an ANAPHYLACTIC REACTION. Anaphylactic reactions can be life-threatening and include rash, vomiting or diarrhea and hypotensive shock. This generally requires IV fluid blues, IV or IM adrenaline injection, etc. In your child, you report that she was given ORS and she felt better after one hour of rest. If she responded without any other treatment, then it is unlikely to have been an anaphylactic reaction.
Studies have shown that severe reactions to JE vaccines are extremely rare and hence need not be a source of concern. Mild problems such as pain, tenderness or swelling at the site of injection, fever, headache, muscle aches and nausea may occur with JE vaccine but are relatively rare as well. Hence, I would advise you not to worry much and go ahead with the second dose.
Dr. Saptharishi L G
Patient replied :
Whether the second primary dose of vaccination is enough to get life long protection from Japanese Enchephalaities
No vaccine can give absolute protection lifelong. It has been found that with two doses of Jenvac, there is up to 98-99 percentage seroconversion and seroprotection. This only means development of antibodies to the virus. Whether this translates into clinical protection or not depends on the child. Jenvac is one of the best vaccines for JE available today, but even this cannot claim absolute, life long immunity. It can only be said that this vaccine reduces your child's risk of acquiring Japanese encephalitis significantly in comparison to an unvaccinated child.