Japanese encephalitis vaccine

Japanese encephalitis vaccine

Japanese encephalitis vaccine is a vaccine used against Japanese encephalitis.[1]

History

Two sorts of Japanese encephalitis vaccines became available in the 1950s. One of them was an inactivated mouse brain-derived vaccine (the Nakayama and/or Beijing-1 strain), made by BIKEN and marketed by Sanofi Pasteur as JE-VAX, until production ceased in 2005. The other was an inactivated vaccine cultivated on primary hamster kidney cells (the Beijing-3 strain). The Beijing-3 strain was the main variant of the vaccine used in the People's Republic of China from 1968 until 2005.[2]

Three second-generation vaccines have entered markets since then: SA14-14-2, IC51 and ChimeriVax-JE. The live-attenuated SA14-14-2 strain was introduced in China in 1988. It is much cheaper than alternative vaccines, and is administered to 20 million Chinese children each year.[3]

A purified, formalin-inactivated, wholevirus vaccine known as IC51 (marketed in Australia and New Zealand as JESPECT and elsewhere as IXIARO) was licensed for use in the United States, Australia, and Europe during the spring of 2009. It is based on a SA14-14-2 strain and cultivated in Vero cells.[2] Another vaccine, a live-attenuated yellow fever-Japanese encephalitis chimeric vaccine known as ChimeriVax-JE (marketed as IMOJEV) was licensed for use in Australia in August 2010.[4]

In 2013, an Indian firm, Bharat Biotech International, developed a vaccine by using the Indian strain of the virus collected from the Kolar district in Karnataka by the National Institute of Virology (NIV). Phase III results of human trials were submitted to the Drug authorities of the Government of India and obtained marketing authorization. It is stated by the representatives of the NIV that the success rate of the vaccine is more than 90% and it can be given to children aged between 1-50 years.[5] [6]

Special Vaccination drive in India

The health ministry of the Indian state of Bihar launched a special vaccination drive to cover 1.8 million children against Japanese Encephalitis on 23 April 2013.[7]

Efficacy

Randomised control trials on JE-VAX have shown that a two-dose schedule provides significant protection for one year.[3]

References