Times of India
08 May 2009
Kounteya Sinha
New Delhi, India

It Will Aid In Understanding How Virus Spreads, Mutates
The genetic code of the deadly H1N1 flu human virus has been cracked–a breakthrough that will now help scientists identify where the virus originated from and reveal how it is presently spreading and how it mutates.

Canadian scientists have become the first to genetically sequence the H1N1 flu virus, vital in developing tests for the infection, and drugs and vaccines to treat it.

Dr David Butler–Jones, Canada’s chief public health officer, said on Wednesday that researchers at the National Microbiology Laboratory in Winnipeg, Manitoba, genetically sequenced three samples of the virus, isolated from Mexico and the Canadian provinces of Nova Scotia and Ontario.

Officials in the Centers for Disease Control and Prevention (CDC) in Atlanta, US, have said that having the full genetic sequence will help them watch how the virus evolves. Though it will not help stop the spread or treat the disease immediately, Butler–Jones said it’s a step forward in understanding how the virus works.

“This is a world’s first. The world’s knowledge of the H1N1 flu virus has taken a significant step forward,” Canada’s health minister Leona Aglukkaq said.

Genetic sequencing of the virus has ruled out a mutation to explain why the Mexican cases have been much more severe than elsewhere.

“We are continuing our analysis, but essentially what it appears to suggest is that there is nothing at the genetic level that differentiates this virus that we’ve got from Mexico and those from Nova Scotia and Ontario. Differences in human genetics could explain why some people fall severely ill while others experience a mild flu,” said Dr Frank Plummer, scientific director–general of the National Microbiology Laboratory, said.

Dr Plummer added, “The Mexican sample decoded was part of the original batch sent to the Winnipeg lab in April, when the country noticed a strange severe respiratory illness had surfaced.”

Canada’s work on the virus has been submitted to GenBank–an international, searchable database–to allow more researchers to have access to the results and benefit from the information.

According to scientists, decoded of the genetic sequence will now allow the development of faster, more accurate tests, using specific viral DNA fragments to prime PCR reactions. The sequence will also permit the synthesis of specific viral proteins. These could be used to induce antibodies in healthy people, which can then be used to treat influenza patients.

Ultimately, viral proteins will be the basis of a vaccine. Genetic sequencing is the process of determining the order of the molecules that make up the DNA in each gene of an organism. This complete genetic blueprint provides important information for researchers studying the virus.

According to World Health Organisation, more Mexicans have died of the virus, but its manifestations have been much more mild in Canada and other infected countries.

Meanwhile, the breakthrough comes a day after another group of scientists from Lawrence Livermore National Laboratory, US, found that the H1N1 flu genes are dissimilar to past pandemics. Some genetic markers of influenza infection severity have been identified from past outbreaks.