WHO’s definition of an influenza pandemic, developed in 2005 in conjunction with the development of a phased system to guide the international response to a new influenza pandemic, was suddenly changed in early May, 2009.

2 May - Mexico revises down suspected swine flu deaths. “Outbreak may be no worse than seasonal flu,” says Mexican health minister, with deaths under investigation cut from 176 to 101.  WHO states that pandemic phases are not related to severity of illness, but simply acknowledges geographical spread.

4 May - After CNN queries discrepancy between what the Director General of WHO is claiming about pandemics not relating to severity and the definition on WHO’s website referring to a  pandemic as, “resulting in epidemics worldwide with enormous numbers of deaths and illness, WHO responds by claiming that the phrase “enormous numbers of deaths and illness” was a ‘mistake’ and withdraws it from the website.