Reaper spiders, or brown spiders, are a family of species found all over the world that produce harmful venoms.
These Loxosceles spiders are mostly prevalent in Brazil, where they cause almost 7,000 human accidents every year.
The new study by researchers from the Universidade Federal de Minas Gerais in Brazil, describes an engineered protein that is made of three pieces of a venom toxin from the Loxosceles intermedia spider.
The engineered protein is not itself poisonous, and gives effective protection against the effects of the pure spider venom in animal models.
Current approaches to protecting against venom involve giving the venom to animals, and taking the resulting antibodies for the serum.
These antibodies enable the human immune system to prepare to neutralize venom from bites although they are somewhat effective, the production of anti-venoms like these is problematic, as animals are required to produce them, and they suffer from the effects of venom.
The new protein is engineered in the lab, without the need for the venomous animals and it is made up of three proteins, so it can protect against more than one kind of toxin at a time.
The protein is also not harmful to the immunized animal, which produce the antibodies and is also more effective than existing approaches, and easier to produce than preparing crude venom from spiders.
Dr. Chavez-Olortegui, corresponding author of the study, said that it is not easy taking venom from a spider, a snake or any other kind of venomous animal.
He said that with their new method, they would be able to engineer the proteins in the lab without having to isolate whole toxins from venom, which makes the whole process much safer.
The researchers tested their new protein on rabbits: all immunized animals showed an immune response similar to the way they respond to the whole toxin.
The engineered protein was effective for venom of the L. intermedia and L. gaucho sub-species that have similar toxins. Immunized rabbits were protected from skin damage at the site of venom injection, and from haemorrhaging.
The study has been published in Elsevier journal Vaccine.