First needle-free COVID-19 vaccine patch

Vaxxas, a biotechnology company has announced the start of its Phase I clinical trial of a needle-free COVID-19 vaccine, delivered via a high-density microarray patch (HD-MAP), giving potential coverage of all major SARS-CoV-2 variants.

The COVID-19 vaccine patch is based on HD-MAP delivery of HexaPro, a second-generation version of the spike protein used in all major US-approved COVID-19 vaccines. The highly stabilised protein is designed to mimic the spike protein’s structure on the surface of the coronavirus. This will help train the trial participant’s immune systems to recognise and combat the infection.

The patch is coated with the vaccine and integrated into a single-use applicator. When applied to the skin, the patch delivers the vaccine to immune cells just under the skin, boosting immune response.

Research data on the innovative COVID-19 vaccine patch

Previous tests observed that the product remained stable and active when stored and transported at room temperature, due to its dry-coating technology. Logistically, this could ease demand on cold chain supply.

“… without the need for extensive refrigeration… our vaccination patch… may enable an accelerated response in a pandemic situation and broader population coverage,” commented Vaxxas Chief Executive Officer David L. Hoey.

The HD-MAP has been tested in three human clinical studies in over 300 participants. However, the new Phase I trial will gather data on its safety, tolerability and immunogenicity, as well as antibody and T-cell responses. The research will observe 44 adults, aged 18–50 years, previously vaccinated with three doses of an authorised COVID-19 vaccine and last vaccinated against the virus at least four months prior to study participation.

Preclinical research published in Science Advances and Vaccine demonstrated that HexaPro enhanced virus neutralising antibody and T-cell responses against all known variants in comparison to needle and syringe vaccination.

“It is important to note that this is our first trial of this promising vaccine patch. We are starting at very low dose with no adjuvants which we know are used regularly with vaccines to stimulate a greater immune response,” stated Hoey. “If the vaccine proves safe, we have a lot of flexibility to increase the dose or supplement the vaccine with an industry standard adjuvant or even mRNA delivery on the patch in future trials if we need or wish to drive an even greater immune response.”

Vaxxas is working to gain Therapeutic Goods Administration (TGA) and US Food and Drug Administration (FDA) approvals for its COVID-19 vaccine patch.