Wednesday, May 6, 2009
Health authorities are warning that the relatively mild swine flu (very few of those infected have died) could mutate into something more deadly.
But for now, it is pretty harmless.
Moreover, people exposed to one version of the virus may sometimes build up immunity to a subsequent, mutated version. For example, the Los Angeles Times writes about the current outbreak:
Ralph Tripp, an influenza expert at the University of Georgia, said that his early analysis of the virus' protein-making instructions suggested that people exposed to the 1957 flu pandemic -- which killed up to 2 million people worldwide -- may have some immunity to the new strain.Similarly, National Public Radio ran a story which included the following:
That could explain why older people have been spared in Mexico, where the swine flu has been most deadly.
Indeed, today, a senior official of the World Health Organization said that people who get - and recover from - swine flu now would be more protected from a similar virus in the future than people who do not get swine flu.
Professor John Oxford at St. Bart's and the Royal London Hospital says there's some reason for cautious optimism.
"In one sense, it's one of the mildest shifts because most people on the planet have got some memory, have come across H1N1 viruses since 1978," Oxford says.
Even though health officials are calling this new virus H1N1, that's also the type of virus that's in wide circulation today. And it has an interesting history. It was the dominant flu virus through the 1920s, '30s and '40s. Oxford says it disappeared in 1957, when it was displaced by another flu virus. But then a strain of H1N1 suddenly reappeared in 1977...
The descendents of this virus are still circulating. He notes that most people who have encountered the newly emerged H1N1 virus seem to have developed only mild disease, and he speculates that's because we have all been exposed to a distant cousin, the H1N1 virus that emerged in the 1970s.
"That escaped virus perhaps will provide some benefit now in the face of this pig thing," Oxford says.This is well-informed speculation, not iron-clad assurance.
Specifically, Keiji Fukuda - former chief epidemiologist in the influenza branch of the U.S. Centers for Disease Control and Prevention, and now WHO's "flu chief" - said that influenza infections generally confer some degree of immunity "for a couple of years." (Fukuda told reporters that after a few years "the viruses themselves change enough so that it's kind of a new virus for your body" and people become susceptible again.)Given that the swine flu is currently not very lethal, but it could mutate to become more lethal, that raises the question of whether getting swine flu now might be a good thing - as it might help build at least some resistance to potentially lethal future mutations.
Note: I am not a medical or health care professional, and this does not constitute health care advice or information. You should not make any medical or health-related decisions without first consulting a medical doctor.
All I'm pointing out is that the fears of contracting swine flu are currently overblown, at least for people who do not have other health problems and while the virus is still relatively harmless .