Researchers at MIT are warning that the threat of a flu pandemic is a real concern, and people need to pay attention to it. They found that many of the H3N2 strains of the virus that are floating around in birds and pigs have a remarkably similar genetic makeup to the “Hong Kong” flu that was so devastating to the global population in 1968. That flu killed approximately one million people, and there is the threat of another one.
Researchers at the Massachusetts Institute of Technology also have said that the current flu vaccines might not be an effective prevention against many of the H3N2 strains that are currently found only in animals. They studied their findings in the May 10, 2013 issue of the journal Scientific Reports.
According to the leader of the study, Ram Sasisekharan, “There are indeed examples of H3N2 that we need to be concerned about,” says Sasisekharan, who is also a member of MIT’s Koch Institute for Integrative Cancer Research. “From a pandemic-preparedness point of view, we should potentially start including some of these H3 strains as part of influenza vaccines.”
How it’s evolved
In the past hundred years, the flu pandemics that have occurred most often started with pigs and birds. Swine and avian flu viruses develop the ability to infect humans, and the virus begins to invade by getting past the immune system, which can only notice common human strains of the virus.
This might seem like serious negative news, but since the Hong Kong pandemic in 1968, many of the H3N2 strains of the virus have been found in humans. This had made them less deadly, and these days, this strain of the flu is even less likely to cause serious illness than flu viruses found seasonally.
There are many strains of the H3N2 virus that are still only found in birds and pigs that have the potential to become a serious threat, should any of the mutate and begin to infect humans.
The research team wondered if there was a risk of the animal strains of H3N2 flu virus mutating to infect humans. If the viruses could infect humans, the human immune system wouldn’t be able to see that the H3N2 virus was harmful to the body, so it wouldn’t fight it.
Many people like to avoid thinking about the H1N1 flu virus that showed its ugly face four years ago, but that one was exceptionally similar to the virus that killed between 50 and 100 million in the pandemic of 1918.
The research team made comparisons between the Hong Kong flu in 1968 H3N2 strain and about 1,100 other strains of H3 flu that are currently found in pigs and bird. The team then focused on the gene that provides the coding for the HA protein.
In short, what they found was that any flu virus has to have the ability to attach to the sugar receptors in the respiratory tract cells of humans. Of the viruses examined there were 581 H3 strains of flu viruses that can cause a pandemic and these strains have only emerged since 2000. Of those that could cause a pandemic, 32 came from pigs, and 549 came from birds.