Two studies regarding the pandemic potential of avian influenza A—H5N1–or “bird flu,” have been published in the journals, Science and Nature, respectively, after careful examination by the U.S. federal government’s National Science Advisory Board for Biosecurity (NSABB).  Both papers were written last year but were not published due to fears that specifics in the research could be misused to endanger public health and national security.   Each of the studies identifies the genetic changes the virus would have to undergo to mutate to a strain allowing airborne transmission between mammals.

It is estimated that H5N1 killed close to 60 percent of 600 people in more than 12 countries since 2003.  Most of these cases involved contact between humans and birds such as infected ducks and chickens.  But scientists have been concerned about that the virus could mutate so that it could be spread from person to person via coughing and sneezing, the same way that other flu viruses such as H1N1, or “swine flu” have in the past.

Dr. Ron Fouchier, from the Erasmus Medical Center in Rotterdam, the Netherlands, and Dr. Yoshihiro Kawaoka of the University of Wisconsin in Madison, Wisconsin the U.S., both conducted studies on H5N1 to investigate how mutated strains of the virus compared to strains of flu that caused human pandemics such as H1N1. 

Fouchier’s team tested artificially mutated strains in ferrets (often used in flu research as they sneeze like humans and show flu-like symptoms when infected) and concluded that just five genetic changes to H5N1 would transform it into a strain that could spread between humans. Kawwaoka’s researchers created a hybrid strain of the H5N1 virus and the swine flu and also tested it on ferrets.  His paper showed that the mutated hybrid would be able to bind to cells in mammals and replicated enough to be spread via respiratory droplets with only four genetic changes. 

The authors of both studies were careful to point out that they cannot predict when or if these genetic mutations might occur, and there are other possible mutations that could spark a pandemic.

After reviewing the studies in the fall of 2011, the NSABB recommended that the information in the manuscripts be published in a redacted form, omitting certain details that might give terrorists guidelines for creating a biological weapon.  In February 2012, the World Health Organization (WHO) convened a technical consultation to discuss the data, how to disseminate the findings in an appropriate manner.  Clarifications were made to the original paper, and finally, in March 2012, the NSABB recommended that the revised manuscripts be made public.

The NSABB offered strong support of the unrestricted communication of research information unless it could be directly misused to pose a serious and immediate risk to public health and safety.  The organization also concluded that:

• The data may benefit public health and surveillance efforts.
• Global cooperation is essential for pandemic influenza preparedness.
• The research was conducted under appropriate conditions.
• There is an urgent need for effective United States and international policies for the oversight and communication of dual research of concern.
• There is a critical need for a mechanism for disseminating sensitive scientific information.

In related news, a study in the June 26 issue of  The Lancet, researchers said that the 2009-2010 swine flu pandemic that actual death counts caused by the virus could be more than 15 times than the number officially recorded by lab tests of the victims.  The new estimates were based on data from countries that keep information on the number of people who developed flu symptoms and also the number of respiratory and heart-associated deaths that occurred during that pandemic.  The results suggest that 80 percent of the deaths occurred in people younger than 65, unusual because most flu deaths occur in elderly people.  The study estimated that the global toll of the H1N1 pandemic could be more than 575,000 deaths.