The National Institutes of Health has started the first in-human trial of an experimental live, weakened Zika virus vaccine.
The vaccine, developed by researchers at the National Institute of Allergy and Infectious Diseases, includes a chimeric virus that is live but weakened, and it prompts an immune response when injected into the body. The vaccine showed promise in earlier tests with monkeys.
Researchers will enroll 28 non-pregnant adults, ages 18 to 50, at the Johns Hopkins Bloomberg School of Public Health Center for Immunization Research in Baltimore and at the Vaccine Testing Center at the University of Vermont's Larner College of Medicine in Burlington. Twenty participants will be randomly assigned to receive a single subcutaneous dose of the experimental vaccine and eight will receive a placebo. The trial is expected to take one year to complete.
Zika is transmitted through the bite of an infected mosquito and can be transmitted via sex. Pregnant women infected with the Zika virus are at a high risk of giving birth to babies with birth defects or those that have health problems in their early years. The U.S. Zika Pregnancy and Infant Registry has recorded 2,474 pregnant women in U.S. states and the District of Columbia that have laboratory evidence of possible Zika virus infection as of July 17.