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By Peter Duveen
I have been following and covering somewhat closely these days the controversy surrounding the origin of the swine flu, called by the U.S. Centers for Disease Control and Prevention (CDC) the "novel flu." In particular, I was interested in the theory of Dr. Adrian Gibbs, who contacted the World Health Organization in May of this year just after people started coming down with the swine flu in Mexico. Gibbs was concerned the novel flu may have been the result of a laboratory accident during the process of producing a flu vaccine.
Gibbs and a colleague, Jean Downie, recently published a research note in which they pretty much spelled out their position on the origin of the novel flu. They continue to refine their theory even though scientists at the WHO have tentatively rejected it.
Gibbs and Downie's position is quite simple. But before describing it, let's first quickly review how vaccination works. In a nutshell, the viruses to be protected against are cultivated in a laboratory, killed using a substance such as formaldehyde, and then injected into the person or animal to be vaccinated. The killed virus does not produce the disease in the vaccine recipient, but it does trigger the production of antibodies that will act to protect the recipient against the live virus.
What do Gibbs and Downie suspect went wrong with this process? They theorize that the three viruses they have identified as the parents of the current swine flu virus were incubated in a laboratory in hen's eggs to produce the starting material for what is called a multivalent vaccine--one that protects against several different types of flu. But the sterilization process was not applied properly, so the viruses in the vaccine were not killed, but rather were in a state where they could actually infect the recipients. When the vaccine was administered, the recipients, probably pigs, came down with the three types of flu. The three viruses multiplied in the infected pigs and exchanged genetic material in a process known as reassortment. A new virus then emerged that incorporated the genetic material of its three parents. It is this new virus that Gibbs and Downie believe has jumped from pigs to humans and has spread around the world.
What evidence does our team of scientists present in support of their theory? Well, they first observe that one of the parent viruses was known to have infected North American pigs, but not European pigs. The two other parent viruses were responsible for flus diagnosed among European pigs, but made no appearance in North America.
In order to have come together to produce the novel swine flu outside of a lab, these viruses would have had to have made transcontinental trips in which the pigs that carried the disease violated quarantines known to have been effective in keeping the European virus out of North America, and the North American strain out of Europe. At least two transcontinental pig shipments, and a similar number of quarantine violations would have had to have been effected in order to get all three parent viruses together to produce the novel flu.
Another problem is that none of these parent viruses has been detected, or sampled, in pigs for at least eleven years, and in the case of one parent virus, as many as seventeen years. How is it, then, that these viruses suddenly emerged in the form of a new composite virus?
A research team led by Dr. Gavin Smith recently published a paper in the scientific periodical Nature proposing that these parent viruses never disappeared, but were circulating undetected in the pig populations since they were last sampled. No explanation, however, is given for why these viruses failed to be detected during standard monitoring procedures.
Gibbs and Downie, in contrast, suggest these viruses were not detected because they were not present in pig populations during this eleven to seventeen year stretch. Rather, they propose, the parent viruses were sitting in a refrigerator in a laboratory, where they had been placedaround the last time each was sampled in infected pigs over a decade ago. They were then recently selected as the raw material to make a vaccine, but in the process of preparation, the viruses were not properly sterilized, and survived. When the tainted vaccine was administered, the live viruses infected the recipients, and a new, highly contagious reassortment of the three emerged to infect, first pig populations for which the vaccine had been prepared, and then humans, who are susceptible to swine flu.
Their research note, which was first circulated about a month ago, has now come to the attention of the public, and is likely being scrutinized by other researchers. Gibbs and Downie have submitted a paper on this topic to a scientific journal, and are awaiting word of its acceptance for publication.
By the way, Gibbs is an authority on viral evolution, and has more than 200 scientific papers to his credit. The WHO's Assistant Director Keiji Fukuda referred to Gibbs as "a credible scientist, a credible virologist." Perhaps that is why he received so much media attention when he first pitched to the WHO the idea that the novel flu was the result of a laboratory mistake.
It ought to be noted how Gibbs and Downie's presentation differs from others positing that the novel swine flu was manufactured in a laboratory, perhaps for malicious purposes. In the early days of the novel flu, it was common to hear statements in the media and the blogosphere such as that the virus was composed of a combination of deadly bird flu, the highly lethal 1918 flu, and pig flu. But Gibbs and Downie say the viruses that demonstrate the closest genetic match to the novel flu virus are all swine flu viruses. In this respect, their analysis differs from the sensational claims, whether ultimately true or not, that the swine flu was introduced as a kind of bioweapon, possibly with a potential kill rate of up to five percent of those infected if it carried the characteristics of say, the 1918 flu, or even as high as 40 percent if bird flu were involved.
Is the question of how the swine flu emerged merely academic? No, say Gibbs and Downie. "Influenza is a significant and very costly cause of mortality and morbidity in the human population," their research note reads. "If we wish to avoid new outbreaks rather than just minimizing the damage they cause, we must better understand what conditions produce them."
(I wish to thank OEN editor John Moffett, whose comments on an article I submitted, but which was not accepted for publication, helped me to fashion the above diary entry.)
