According to research by the Indian Council of Medical Research (ICMR) published in the Journal of Travel Medicine, the effectiveness of the vaccination given to protect children against Japanese Encephalitis (JE) tends to start declining after two years, necessitating the administration of a booster dose to all children in endemic areas.

The majority of JE′s victims are children under the age of 15. Approximately 25% of the affected youngsters die, and 30% to 40% who survive experience physical and mental damage.

Researchers collected blood samples from 266 children aged two to ten years who were administered two doses of the vaccine from one of Uttar Pradeshs JE-endemic locations and examined the samples for antibodies specific to the JE virus.

Test results showed that anti-JE virus-specific IgG antibody titers were declining across all age categories. Among 266 samples, 260 (98%) were negative, and 6 (2%) were ambiguous. The first dose of the JE vaccine is typically given between 9 and 12 months of age, and children in endemic areas receive the second dose between 16 and 24 months of age.

During 2021 in India, only the states of UP and Assam recorded over 300 cases of JEV. According to ICMR experts, Eastern UP has a higher incidence rate of JE due to agro-climatic conditions, particularly rice fields. These findings highlight the importance of booster vaccination doses for kids living in endemic areas.