A super-vaccine to prevent both Zika and dengue fever is on the horizon after scientists found that the viruses can be neutralised by the same antibodies.
Antibodies work by combining with bacteria and viruses so that the immune system knows what to attack. They also carry a memory of the invader to stop it coming back.
But because Zika was not believed to be a dangerous virus until recently scientists have not yet managed to isolate the antibodies needed to produce a vaccine.
However now researchers at the Pasteur Institute in France have found that antibodies generated from people infected with dengue can bind with zika to prevent infection.
A vaccine for dengue was recently approved for use by the World Health Organisation so it is possible that it may also protect against zika.
Felix Rey said: “What we found was that an antibody against dengue can very potently neutralize Zika virus as well.
“An individual will make antibodies against zika virus when infected by zika but nobody worked in isolating antibodies against zika virus until now, because it was not considered a dangerous virus.
“It is only now that everybody is paying attention to Zika virus, but nobody yet has antibodies against Zika virus.”
The dengue virus is similar to the Zika virus – they belong to the same viral family, called the Flaviviridae, and both are transmitted by the Aedes mosquito. Some 50 countries are now infected and thousands of babies have been born with birth defects, usually with shrunken heads and brain damage.
However dengue comes in four different forms, and a separate report by Imperial College found that antibodies against one form will not protect against the others. In fact, it could make the infection worse.
So people who have been infected by dengue will become more ill if they are infected with Zika. The finding has implications for a new vaccine as vaccinating with the wrong antibodies could make any subsequent infection much worse.
Professor Gavin Screaton, senior author of the research and Dean of the Faculty of Medicine at Imperial, said: “Although this work is at a very early stage, it suggests previous exposure to dengue virus may enhance Zika infection.
“This may be why the current outbreak has been so severe, and why it has been in areas where dengue is prevalent. We now need further studies to confirm these findings, and to progress towards a vaccine.”
Dr Jeremy Farrar, Director of the Wellcome Trust, which funded the research, said: “Zika and dengue come from the same family of viruses and we know they share many similarities in their genetic make-up, transmission pattern and in the immune response they trigger.”
Both papers were published in Nature Immunology.
Source: The Telegraph