Deadly doses: The polio vaccine causes new infections

In the 1990s, one of the World Health Organisation’s stated goals for the new millennium was to eradicate polio by 2000. Sadly that deadline was not met, despite intensive campaigns in the remaining affected regions – west Africa and south Asia. Now polio is starting to spread again – particularly in Nigeria. Even more disturbing is the fact that some of the new cases are the result of a mutated polio virus that originated in one of the vaccines used to prevent infection.