A jab that protects against poisonous spider venom may become a reality one day, early research suggests.
A new generation of anti-venom vaccines could save thousands of lives a year, researchers report in Vaccine journal.
The spider tested, belonging to the genus Loxosceles, injures almost 7,000 people a year in Brazil alone.
Members of this group of spiders, which are found worldwide, include the reaper or brown spider. Their bite causes open sores and can lead to more serious effects such as internal bleeding and kidney failure.In experiments, researchers used part of the spider toxin to create a synthetic protein designed to raise antibodies against the venom.
"Existing anti-venoms are made of the pure toxins and can be harmful to people who take them," said Dr Carlos Chávez-Olortegui, of the Universidade Federal de Minas Gerais in Brazil.
"We wanted to develop a new way of protecting people from the effects of these spider bites without having to suffer from side-effects."
Scientists say the research could be the start of a new generation of anti-venom vaccines capable of saving thousands of lives worldwide.
The researchers tested the new protein on rabbits in the laboratory.
They say immunised rabbits were protected from skin damage at the site of venom injection, and from haemorrhaging