The leader of the World Health Organization criticized the drug industry on Monday, saying that the drive for profit was one reason no vaccine had yet been found for Ebola.

In a speech at a regional conference in Cotonou, Benin, Dr. Margaret Chan, the director general of the W.H.O., also denounced the glaring absence of effective public health systems in the worst-affected countries.

At least 13,567 people are known to have contracted the Ebola virus in the latest outbreak, and 4,951 have died, according to the latest data on the W.H.O. website, which was updated on Friday. All but a few of the cases have been in Guinea, Liberia and Sierra Leone.