The team, led by researchers at Imperial College London and Washington University in St Louis, found that the antibodies taken from the patients infected with Dengue virus not only prevented Zika-infected mice, but also protected pregnant woman's fetus from the infection.
According to the researchers, if the findings replicated in humans, the discovery could potentially lead to a single therapy to protect against both viral threats.
The team has shown for the first time that these antibodies - Y-shaped proteins, which recognise the virus and stick to its surface to single out Dengue for destruction of body's immune cells - are effective in treating Zika infection in mice.
Zika is from the same family of viruses (called Flaviviridae) as Dengue and is transmitted by the same species of mosquito.
Senior author Gavin Screaton from College London said that the paper shows for the first time that the antibodies they had previously found to be effective against Dengue can potently protect against Zika virus in mice.
For trials, animals infected with Zika were treated with the antibodies of Dengue in the first five days of infection and monitored were for 21 days.
They found that treatment with the antibodies reduced deaths and weight loss in the rodents when compared to a control group.
They also found that the treatment was able to reduce the damage caused by the virus, furthermore, tests in pregnant mice infected with Zika reduced the deaths of unborn pups to just one in 10, compared to a 90 percent loss seen in infected control animals.
The results also revealed that the antibody treatment was associated with a drastic reduction in the amount of virus detected in the brain and testes, sites known to be targeted by Zika.
The research appears in the journal Nature Immunology. (ANI)