These effects were shown in some animal experiments. Animals that had been previously exposed to dengue or West Nile virus had worse Zika infection and symptoms, which suggests a similar risk for individuals with prior exposure to dengue. (Such exposure would be common in areas, such as South America, where both viruses are endemic.) According to Dr. Chen, “If you have prior exposure to dengue, and then have Zika exposure, the Zika infection may be much worse, and for men, may increase the likelihood of sexual transmission.”
This makes ASU’s protein-based vaccine that much more desirable in that it should be able to circumvent those interactions. The ASU vaccine uses “the smallest and most unique part of the Zika virus that can still elicit a potent and robust immune response.” Dr. Chen elaborated on this in the press release, stating, “In our approach, we make what we call a pseudovirus. It's a fake virus. The pseudovirus displays only the DIII part of the envelope protein on the surface. This is at least as potent as previous vaccine versions.” This makes Dr. Chen confident that the ASU vaccine is safer than other protein-based vaccines.
He continued, “We did a test to make sure that the vaccine produces a potent protective immune response, but also, that it does not produce antibodies that may be cross reactive for dengue, West Nile, yellow fever or others.”
Thanks to a grant from the National Institute of Allergy and Infectious Diseases (NIAID), seed funds from the Biodesign Institute, and federal, state, and public support, the team at ASU has been able to move from the idea for the vaccine to the proof-of-concept quickly. According to the press release, the team “hopes to partner with the medical community to begin the first phase of a human clinical trial in the next 2 years,” arguably welcome news for the hundreds of women who are faced with the threat of infection every day.
The full study
was published online in Scientific Reports
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