Chris - What are the present theories about how they arise?
Adrian - Well, the simplest theory that has been put out is that perhaps it’s an entirely natural occurrence. We believe that most ‘flus are getting around in birds so presumably it’s got around in birds. However, this new flu shows no relationship with birds. All of its most immediate ancestors are viruses of pigs. Therefore, you’ve got to believe where it’s got around in pigs. But the real problem with that is that it clearly has three separate parents. And one of those parents was in North America some years ago. One was in South East Asia. And one was in Europe. So you got to think of getting three pigs from different parts of the world together to make the new virus.
Chris - So what you’re saying is when you, sort of, molecularly interrogate the genetic history of what we’re seeing as the H1N1 swine flu pandemic, you can see that it must have three independent bits of parentage. And the big question is, “Well, how on Earth did all those parents come together to infect the first person who got this?”
Adrian - That’s right. So if they were brought together by pigs, for example, say through live pig trade between continents, it means that quarantine, which has worked for dozens of years in the past, has somehow broken down on at least two occasions. If you got to get three things together in one part of the world, one might be there originally. The other two have to come through quarantine to leave the country and come through quarantine to get into a country. So that’s one possibility. The other possibility which we have put into this paper that we have published is that we’ve been thinking, could have they got together by some sort of laboratory error? We know that virologists pass viruses from one another around the world for use in their laboratories, for identification, for making vaccines and so on. What sort of conditions might three viruses have got together in one place in order to be able to shuffle their genes and produce the new pandemic flu?
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