The National Institute of Allergy and Infectious Diseases
(NIAID) has launched a clinical trial of an experimental vaccine to prevent
Zika infection.
Part of the National Institutes of Health, NIAID’s study
will test the safety of the vaccine and its efficacy in creating an immune
response in at least 80 healthy human volunteers ages 18-35.
“A safe and effective vaccine to prevent Zika virus
infection and the devastating birth defects it causes is a public health
imperative,” said NIAID director Dr. Anthony Fauci. “NIAID worked expeditiously
to ready a vaccine candidate, and results in animal testing have been very
encouraging. We are pleased that we are now able to proceed with this initial
study in people. Although it will take some time before a vaccine against Zika
is commercially available, the launch of this study is an important step
forward.”
Developed by NIAID’s Vaccine Research Center, the drug being
tested is a DNA vaccine, which does not contain infectious material and cannot
cause those who receive it to contract Zika.
“A team of scientists here at NIAID worked tirelessly to
rapidly develop this vaccine for clinical testing,” said Dr. John Mascola, director
of NIAID’s Vaccine Research Center. “DNA or gene-based vaccines induce
antibodies, but they also can activate the cell-mediated immune response, which
ultimately could yield strong and durable protection against disease.”
NIAID is the second group to begin human testing of a Zika
vaccine in the U.S. Following FDA approval, on July 26 Inovio Pharmaceuticals
and GeneOne Life Science dosed their first subject with synthetic vaccine
GLS-5700.
“In preclinical testing, this synthetic vaccine induced
robust antibody and T cell responses — the immune responses necessary to fight
viral infections — in small and large animal models,” said Inovio via press
release.
Their first-phase dose-ranging study will use 40 volunteers
in Miami, Philadelphia and Quebec City. Preliminary results are expected later
this year.
In the first phase of the NIAID trial, participants will be
divided into four groups. All volunteers will receive an initial vaccination,
after which the groups will receive one or two additional administrations of
the vaccine at different time intervals. Over the following months,
participants will return for follow-up testing to determine the safety of the
drug and the immune response. Additional visits at 18 months and two years will
measure the longevity of the immune response.
Initial data from Phase 1 is expected in January 2017, and
if the vaccine appears promising, NIAID will begin Phase 2 testing in countries
where Zika is endemic soon after.