The H1N1 swine flu virus that has killed more than 1,200 people in India this year may be stronger than the 2009 strain that caused 18,000 deaths in 74 countries.
Scientists at the Massachusetts Institute of Technology (MIT) analyzed the two strains of flu and published their findings today in the journal Cell Host & Microbe.
The researchers said their findings contradict reports from Indian health officials who say this year’s strain has not changed from the version that emerged in 2009 and has been circulating around the world during the past six years.
The researchers said this year’s virus may have acquired mutations that are known to make it more virulent.
One of the new mutations is in an amino acid position called D225, which has been linked with increased disease severity. Another mutation, in the T200A position, makes the virus more infectious.
And these mutations may make the newer virus more resistant to current H1N1 vaccines.
The flu season in India is winding down, but the researchers still recommend health officials study the virus there in more detail. They also suggest stricter surveillance of this and future flu outbreaks, as well as a new strategy to formulate vaccines.
“We’re really caught between a rock and a hard place, with little information and a lot of misinformation,” said Ram Sasisekharan, the Alfred H. Caspary professor of biological engineering at MIT and the paper’s senior author. “When you do real-time surveillance, get organized, and deposit these sequences, then you can come up with a better strategy to respond to the virus.”
“The goal is to get a clearer picture of the strains that are circulating,” he added, “and therefore anticipate the right kind of a vaccine strategy for 2016.”
However, a flu expert at the University of California, Berkeley says getting that clearer picture may be more difficult than the MIT researchers suggest.
“It’s challenging to predict what any influenza strain is going to do,” said Dr. Arthur L. Reingold, a professor and head of epidemiology at Berkeley.
Reingold said there are two overarching questions about the flu outbreak in India. One is exactly what strain is causing it. The other is how bad an illness it will cause.
“Both are difficult to predict,” Reingold said.
He agreed it’s “quite likely” this year’s flu in India is a different strain than the 2009 version because flu viruses change quickly and often strains are only prevalent for a few years.
“It’s a dilemma everywhere that we don’t have a good answer for,” he said.
Reingold added India is a country with more than 1 billion people but without a well-organized vaccine program.
“In the real world, things like this can be difficult to accomplish,” he said.