Role of drug delivery technologies in the success of COVID-19 vaccines: a perspective.

The triumphant success of mRNA vaccines is a testimony to the important role drug delivery technologies have played in protecting billions of people against SARS-CoV-2 (or the Corona Virus Disease 2019; COVID-19). Several lipid nanoparticle (LNP) mRNA vaccines were developed and have been instrumental in preventing the disease by boosting the immune system against the pathogen, SARS-CoV-2. These vaccines have been built on decades of scientific research in drug delivery of mRNA, vaccines, and other biologicals. In this manuscript, several leading and emerging scientists in the field of drug delivery share their perspective on the role of drug delivery technologies in developing safe and efficacious vaccines, in a roundtable discussion. The authors also discussed their viewpoint on the current challenges, and the key research questions that should drive this important area of research.

An ultra-low-cost electroporator with microneedle electrodes (ePatch) for SARS-CoV-2 vaccination.

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens with pandemic potential requires safe, protective, inexpensive, and easily accessible vaccines that can be developed and manufactured rapidly at a large scale. DNA vaccines can achieve these criteria, but induction of strong immune responses has often required bulky, expensive electroporation devices. Here, we report an ultra-low-cost (<1 USD), handheld (<50 g) electroporation system utilizing a microneedle electrode array ("ePatch") for DNA vaccination against SARS-CoV-2. The low cost and small size are achieved by combining a thumb-operated piezoelectric pulser derived from a common household stove lighter that emits microsecond, bipolar, oscillatory electric pulses and a microneedle electrode array that targets delivery of high electric field strength pulses to the skin's epidermis. Antibody responses against SARS-CoV-2 induced by this electroporation system in mice were strong and enabled at least 10-fold dose sparing compared to conventional intramuscular or intradermal injection of the DNA vaccine. Vaccination was well tolerated with mild, transient effects on the skin. This ePatch system is easily portable, without any battery or other power source supply, offering an attractive, inexpensive approach for rapid and accessible DNA vaccination to combat COVID-19, as well as other epidemics.