Pandemic flu vaccine research poses risk of unintended release

Transmission electron micrograph of avian influenza A H5N1 viruses (gold) grown in Madin-Darby canine kidney (MDCK) cells (green)--Courtesy of CDC

Virulent flu strains pose the danger of potential release, even when used in experiments for vaccine research, and investigators from Harvard and Yale universities are calling for greater scrutiny of such studies.

In an editorial published May 20 in PLOS Medicine, the researchers said recent studies reporting the creation of virulent avian flu strains that pass between ferrets, which respond to the virus similarly to people, are troublesome because they put human life at risk. The authors are calling for strict guidelines for flu research that uses safe, alternative approaches in the lab.

Experiments on so-called novel potential pandemic pathogens (PPPs) are conducted under high levels of biosecurity, but author Marc Lipsitch, professor of epidemiology and director of the Center for Communicable Disease Dynamics at the Harvard School of Public Health, says the potential benefits of experiments on PPPs do not outweigh the risks from an accidental release and global spread.

An outbreak of H1N1 influenza in 1977 that continued to circulate for 20 years was believed to have been accidently released from a lab in Russia or China.

Lipsitch and Yale's Alison Galvani suggest that the U.S. government and other funders conduct a comprehensive risk-benefit analysis before backing further PPP studies. They estimate that if 10 high-containment labs in the U.S. were running PPP experiments for a decade, there would be a nearly 20% risk of at least one laboratory-acquired flu infection with the potential to spread. In countries operating under less rigid guidelines than the U.S., the risk would be even greater.

Lipsitch and Galvani say that safe and effective scientific alternatives exist for studying influenza that do not pose health risks, such as sequence analysis and molecular-dynamics modeling to pinpoint the genetic determinants of traits that predict how pandemic flu strains might spread among animals and humans.

- see the press release
- read the editorial in PLOS Medicine