A prototype high-density microarray patch (HD-MAP) shows promise in pre-clinical studies for delivering novel, needle-free vaccine against Zika virus.
HD-MAP was developed at the University of Queensland and commercialized by Vaxxas. The needle-free patch served as the platform for the University of Adelaide-developed vaccine (pVAX-tpaNS1) vaccine elicited an effective immune response to Zika virus in mice.
“We can change the way we combat Zika virus with the HD-MAP patch because it is an effective, pain-free, simple to apply, and easy to store vaccination method,” said UQ alum and Vaxxas researcher Dr. Danushka Wijesundara. “HD-MAP delivers the vaccine to immune cells beneath the skin’s surface with thousands of tiny microprojections. In our pre-clinical trial, the vaccine provided rapid protection against live Zika virus, targeting a specific protein called NS1 which is crucial to the virus’s survival.”
In a recently published study, the vaccine patch evoked T-cell responses that were about 270 percent higher than from a needle or syringe vaccine delivery.
Zika virus generally causes a mild illness but infection in pregnancy can lead to miscarriage and stillbirths or infants born with congenital malformations.
In February 2016, the World Health Organization declared a Public Health Emergency of International Concern when Zika virus spread across 40 countries in Latin America, causing more than 1.5 million confirmed or suspected cases in a 6-month period.
“This vaccine is unique because it targets a protein inside, rather than outside of the virus meaning it won’t enhance the symptoms of closely related viruses such as dengue fever, in people who’ve been vaccinated.”University of Adelaide’s Associate Professor Branka Grubor-Bauk
“Because the protein we’re targeting plays a central role in replication in a virus family known as flaviviruses, there’s the potential to apply our approach to target other flaviviruses such as dengue or Japanese encephalitis,” Dr. Muller said.
“It could also deliver a vaccine mixture to target the whole family of viruses, providing greater protection. A major benefit of the HD-MAP delivery platform is vaccine stability at elevated temperatures – we found the patch retained vaccine potency when stored at 40 degrees Celsius for up to four weeks. This increases the reach of vaccines in low- and middle-income countries where refrigeration is challenging.”
Superior efficacy of a skin-applied microprojection device for delivering a novel Zika DNA vaccine. Molecular Therapy Nucleic Acids, 17 October 2023.