'We were trying to understand how different the Indian variants are, and we found that they are very different from the original strains used to develop the vaccines,' said Roy. Cross-serotype protection is lost as antibody levels gradually start to decline.Īnd these recent findings only serve to highlight how critical it is to develop a vaccine against the dengue virus.

As per scientists, if the second serotype resembles the first, antibodies produced in the host's blood during the initial infection will bind to the new serotype and do the same with immune cells known as macrophages.Īfter initial infection, the body produces antibodies that offer total defence against all serotypes for two to three years. Suraj Jagtap, the study's lead author, said that in some cases, people might contract one serotype initially before developing a secondary infection with a different serotype, which causes more severe symptoms. However, Dengue 2 had recently gained ground nationwide while Dengue 4, which was once thought to be the least contagious, was now carving out a presence in South India. It was found that Dengue 1 and Dengue 3 were the predominant strains in India up till 2012. 'We found that the sequences are changing in a very complex fashion,' said Roy, one of the study's authors. The team at IISc analysed 408 genomic sequences of dengue strains collected from Indian patients between 19. This led researchers to take a look at the four serotypes of the dengue virus and calculate how far each one had diverged from its ancestral sequence. Once the virus has entered the human body, it replicates and spreads to other organs such the liver, spleen, and lymph nodes, resulting in various symptoms like nausea, vomiting, aches and pains.Īnd South-East Asian countries have seen the majority of the steady rise in mosquito-borne viral diseases during the past five decades. It is carried by the Aedes mosquito, which picks up the virus when it bites an infected person and spreads it to its next victim. The dengue virus, with its four serotypes DEN-1, DEN-2, DEN-3, and DEN-4, is a member of the Flaviviridae family. However, the dengue virus has hardly remained the same over the decades.Ī new IISc-led study that consisted of the computational analysis of the virus over the last sixty years has shown that the dengue virus has evolved dramatically in India! Since its first documentation in 1945, dengue has pretty much made a home for itself in India, taking advantage of the tropical climate the country has to offer.

Virus tropical by Powerpaola