By Corinne Podger BBC science reporter

The results of a study published in this week's issue of the medical journal, The Lancet, highlight the success of a World Health Organisation campaign to eliminate measles in Africa.

Measles is the most contagious disease known to humanity, and causes nearly a million deaths a year - almost as many deaths as malaria.

Around half of the deaths from measles occur in African countries.

Over a four-year period, WHO and health agency workers immunised nearly 24 million children in seven African countries - Botswana, Lesotho, Malawi, Namibia, South Africa, Swaziland and Zimbabwe.

Immunisation

The vaccination programme included initial shots at nine months of age, and follow-up campaigns to immunise older children.

The results found that the number of cases fell from 60,000 in 1996 to less than 200 by the year 2000, and the number of deaths dropped from 160 to zero.

Immunisation campaigns have been the subject of debate in recent years.

Some critics argue that poorer countries lack the health infrastructure necessary to make them work.

The researchers who led this latest campaign against measles say its dramatic success is clear evidence that vaccination programmes can be effective in even the poorest communities.