Institut Pasteur receives patent for West Nile virus vaccine

Virus belongs to Japanese Encephalitis group of pathogens, causes an infectious disease prevalent in various parts of India

Institut Pasteur, a private non-profit foundation with a mission to help prevent and treat infectious diseases, has received an Indian patent for a lentiviral vector-based vaccine. The drug is to be used to prevent West Nile virus, an infectious disease reported in various parts of the country, including north-east India.

According to the World Health Organisation (WHO), the West Nile virus can cause a fatal neurological disease in humans, though approximately 80 per cent of people who are infected will not show any symptoms. The virus is mainly transmitted to people through the bites of infected mosquitoes. It can cause severe disease and death in horses. Vaccines are available for use in horses but not yet available for people, WHO says. Birds are the natural hosts of the virus. This pathogen is a member of the flavivirus genus and belongs to the Japanese encephalitis antigenic complex, it says.

The patent application filed in May 2008 came up for hearing on March 2016, after various procedures. The patent office had raised objections and the foundation had provided responses during the hearing, besides carrying out some amendments in their claims.

The institute claimed that the invention is to provide a vector to stimulate an antibody-based protective immunity, that is, to elicit a humoral response in an animal against a West Nile Virus antigen. It claimed that the inventors have surprisingly found that a single immunisation with a minute dose of a non-replicative lentiviral vector has shown a specific body fluid related response and protection against the West Nile Virus infection in a mouse model of the viral encephalitis. This single immunisation resulted in a long-lasting, protective and sterilising body fluid related immunity. This lentiviral vector can therefore be used for preparing a medicine which could produce antibodies when administered in a single minute dose, to be used as a preventive measure to this virus, it claimed.

Considering the oral and written submissions, the Patent Office decided to grant patent to the invention.

WNV is commonly found in Africa, Europe, the Middle East, North America and West Asia. In India, according to reports, the virus has been identified in North Eastern India and States like Tamil Nadu and Kerala in the past.