Scientists working on a vaccine against river blindness, or onchocerciasis, have identified three potential vaccine compounds that could offer protection, it was announced yesterday.
Professor David Taylor of Edinburgh University, UK, is collaborating on "The Onchocerciasis Vaccine for Africa" project with researchers the Cameroon Academy of Sciences and Kwame Nkrumah University, Ghana, West Africa.
They explain that onchocerciasis affects about 17 million people globally, mostly in west and central Africa. It is described by the World Health Organisation as a neglected tropical disease, and the WHO has set a target of eliminating the disease from Africa.
The disease is a caused by infection with the parasitic worm Onchocerca volvulus, transmitted by blackflies that breed in rivers. This leads to eye conditions in about 10% of infected people. 1% become blind and 70% develop very severe skin diseases, according to the researchers.
The current drug treatment for onchocerciasis is called ivermectin, or Mectizan. It is effective but cannot be given to children under five or those infected with eye worm Loa loa. The drug also carries a risk of severe side effects.
Professor Taylor and his team have carried out experiments leading to three potential vaccines. In a statement released on Monday (11 January), they write that at least one of these could be tested in safety trials by 2020 and trials to test its effectiveness by 2025.
If successful, hopes are that the vaccine would be offered to children as part of national immunisation programmes.
"New knowledge of the way nematode parasites regulate people’s immune responses has guided formulation of experimental vaccines," says Professor Taylor. "A vaccine against river blindness would complement and augment existing treatment and significantly improve the prospects for eliminating this disease from Africa."
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