JE vaccines: Recent study puts efficacy at 60%; Nepal-based study put it at 96%

The draft of the research,which has been circulated to various experts for review,reflects that these findings are contrary to the findings of the Nepal-based study.

The JE vaccine was introduced in India in 2006 but there was no zero-surveillance study to know its efficacy on Indian children.

The vaccine was introduced in India by taking the Nepal-based study as the base,according to which

JE vaccine provided around 96 per cent immunity to children.

With the need increasingly being felt that India should have its own study on vaccine efficacy,National Technical Advisory Group on Immunisation recommended the

Central government the same in 2008.

After some delay,the study,undertaken by the Indian Council for Medical

Research,began in 2009,studying around 1,000

children in Uttar Pradesh and Assam in the JE-affected high-risk areas.

While 750 children were covered in Uttar Pradesh,including 150 suspected or positive cases,and four controls against each case,250 children were covered in Assam with 50 cases and 200 controls.

In Uttar Pradesh,Gorakhpur-based National Institute of Virology,Pune wing,in support of BRD Gorakhpur has pursued the study.

In Assam,the study was undertaken by Regional Medical Research Centre of ICMR along with the Army Medical College.

“The study is very significant as for a long time we have been raising questions over vaccine efficacy in India and have demanded at least two dozes of JE vaccine within the first two years to provide the right kind of immunity. We are now waiting for the results to be printed soon,” said Dr R N Singh,who has been actively pursuing encephalitis eradication efforts in eastern UP and is based in Gorakhpur.

He added: “These are just the preliminary findings. I believe once the report comes out in print,the efficacy in some parts of eastern Uttar Pradesh would come to be around 50 per cent.”

One of the experts said there are two factors,which might have led to low-vaccine efficacy in Uttar Pradesh.

First,parents or doctors in UP were not able to provide proper proof of vaccination of the child and thus many times experts had to depend on the parents’ word,which was not the case in Assam. Second,there is certainly low-immunity among children in UP with many entero-virus circulating here.

Meanwhile,despite declaring a special round for JE vaccine in Gorakhpur and Basti division of Uttar Pradesh,the Central government has so far not been able to provide adequate supply of fresh JE vaccine to Uttar Pradesh.