Hernán Cortés owed his conquest of the Aztecs to his expedition's unknown, unseen secret weapon: the smallpox virus. Disease epidemics can set the course of human history.
The global target to eradicate polio is being missed because a number of countries are struggling to reach high vaccine coverage.
Humans have shown that together we can overcome daunting problems, including deadly pathogens like smallpox. It is a lesson of international cooperation and respect that we should pay attention to.
A disease suspected to be monkeypox is on the rampage in Nigeria. In less than one month, it has spread to seven of the country's 36 states and infected 31 people.
Despite being so small they can't be seen with the naked eye, pathogens that cause human disease have greatly affected the way humans live for centuries.
Here we explore our past and present struggles with the most significant infectious diseases human beings have faced.
Edward Jenner deliberately infected a young boy with cowpox and then smallpox. But his method wasn't as mad as is often made out.
The positive impact of the polio eradication initiatives on the continent can be felt across the health sector in other health programmes.
It's been one year since the last polio case was reported in Africa. If the continent keeps this up, it could be declared polio free by 2018.