Police chiefs and health experts are attending a two-day Interpol conference in the French city of Lyon to assess the risk of biological terrorism.
The international police organisation says it is the world’s first such event. More than 400 officials from 120 countries are participating.
The head of Interpol, Ron Noble, told the BBC that the world was ill-prepared for the bio-terrorism threat.
He said the risk of another major al-Qaeda strike had not diminished.
Mr Noble denied that governments had played up the risk, and warned that a biological attack would quickly spread globally.
The conference in Lyon – the headquarters of Interpol – will include case studies.
A representative of the US Postal Service will analyse the anthrax scare that shook the US in 2001, the BBC’s security correspondent Gordon Corera reports.
The conference is aimed at encouraging intelligence agencies and police forces to share information and co-operate more closely against the biological threat.
Speakers include former Commissioner of the Metropolitan Police Service Sir John Stevens and Commissioner of the Royal Canadian Mounted Police Zack Zaccardelli.