This article was published last May. It reflects the official position of the WHO regarding the origins of the A H1N1 virus.

May 14, 2009 — The World Health Organization (WHO) is refuting claims made by an eminent virologist that the novel H1N1 strain that is circulating is derived from a laboratory.

Keiji Fukuda, MD, MPH, assistant director-general ad. interim for health security and environment at the WHO, spoke at a press conference today.

According to Dr. Fukuda, on Saturday, May 9, the WHO was contacted by Dr. Adrian Gibbs, who Dr. Fukuda referred to as a “credible” virologist. After looking at the gene sequence of H1N1, Dr. Gibbs speculated that the virus circulating may have been from a laboratory-derived virus.

Dr. Gibbs, an emeritus professor at the Australian National University in Canberra, said that all 8 of the genes from the novel H1N1 strain seemed to have evolved at a faster rate than would have been expected if the virus had just emerged naturally from pigs.

Dr. Fukuda stated that the WHO discussed the hypothesis provided by the scientist and they contacted the UN Food and Agriculture Organization (FAO) and the World Animal Health Organization (OIE). WHO asked their virologists to “look at the evidence and then provide their opinion to us — was this a credible hypothesis or not?” he said.

“Based on that evaluation by all of the laboratories, the conclusion is that this group of scientists feels that the hypothesis does not really stand up to scrutiny,” Dr. Fukuda said. “The evidence suggests that this is a naturally occurring virus and not a laboratory-derived virus.”

Dr. Fukuda also used the press conference to clarify some confusion evident in certain media reports. “WHO is not making any changes in its recommendation about antiviral use,” he said. He also emphasized that they have not seen any evidence of increased resistance to antivirals, although they will continue to monitor for any evidence of resistance.

As of [May 14, 2009], the WHO is reporting a total of 6497 laboratory-confirmed cases, including 65 deaths, in 33 countries. Today’s number represents an increase of 769 cases from yesterday. The US Centers for Disease Control and Prevention is reporting 4298 confirmed and probable cases in 46 states and the District of Columbia and a total of 3 deaths in the United States.

For now, daily WHO press briefings will be discontinued, according to Dr. Fukuda. The decision is more because of upcoming WHO meetings and a desire not to spread the staff “too thin” than because of any abatement of the H1N1 epidemic, he pointed out.

“This is an event which is serious; this is something which requires close monitoring, but most of the cases at this time continue to be mild cases…although there are some people who do get fatalities and serious illnesses,” he said.

No “big decisions” have been made yet about H1N1 vaccine production, although the initial steps for producing are under way, he said.

Emma Hitt is a freelance editor and writer for Medscape.