Establishing Immunogenicity and Safety of Needle-free Intradermal Delivery of mRNA COVID-19 Vaccine
Status:
Recruiting
Trial end date:
2023-05-01
Target enrollment:
Participant gender:
Summary
COVID-19 vaccines are limited in supply, especially in low- and middle-income countries,
leading to substantial morbidity and mortality. Despite the COVID-19 Vaccines Global Access
(COVAX) Facility initiated by the WHO to provide vaccine access for low-income countries,
probably 80% of the vaccine needs of participating countries will not be met soon.
In addition, there is an increasing demand for revaccination of the population globally,
because of waning immunity which will further limit vaccine supplies. Exploring dose-sparing
techniques, could therefore provide the solution to immunise more people with the same
vaccine stockpile.
The intramuscular injection (IM) is the standard inoculation route of vaccines. However, the
skin (dermis) is much richer in antigen presenting dendritic cells than muscle. As a
consequence, a fractional vaccine dose introduced directly into the dermis (intradermal
administration, ID) might be as effective as the intramuscular administration of the full
standard dose to achieve a protective immune response. This principle has recently been
demonstrated for the ID dermal delivery of one-fifth fractional dose mRNA-1273 (Spikevax,
Moderna) vaccine.
However, needle-based immunisation has several limitations. Fear of needles makes
immunisation a stressful event. In addition, needle stick injuries, as well as unsafe
injection practices carry serious health risks. Therefore, the development of needle-free
delivery has been identified as an important goal in global health care. The WHO reported
that microneedle vaccine delivery is top priority and requires additional research to explore
the benefits in more detail. A big advantage of intradermal delivery via a solid needle patch
is not only the absence of needles and pain since no nerves are at the proximity where the
needles are presented, but also the local delivery close to immune cells as with the above
mentioned intradermal injection enables a much lower dose as compared to IM dosing. And since
with the patch a larger skin surface is involved as compared to intradermal injection, even
lower doses are possibly still immunogenic.
In this study, we will investigate the immunogenicity and safety in healthy volunteers of the
needle-free intradermal delivery of a single fractional dose of 20µg mRNA-1273 LNP vaccine
(Spikevax, Moderna) more than 3 months after primary vaccination with Comirnaty (Pfizer)
vaccine and/or after having contracted COVID-19.