On Apr. 14, 2020, researchers from the University of Pittsburgh announced that they had adapted a system to produce a candidate MERS vaccine to rapidly produce an experimental vaccine using the SARS-CoV-2 spike protein. The study appeared online in EBioMedicine, a Lancet journal.

The team developed a method for delivering their MERS vaccine into mice using a microneedle patch. Such patches resemble a piece of Velcro, with hundreds of tiny microneedles made of sugar. The needles prick just into the skin and quickly dissolve, releasing the vaccine.

When delivered by microneedle patch to mice, three different experimental MERS vaccines induced the production of antibodies against the virus. These responses were stronger than the responses generated by regular injection of one of the vaccines along with a powerful immune stimulant (an adjuvant). Antibody levels continued to increase over time in mice vaccinated by microneedle patch—up to 55 weeks, when the experiments ended.

Using knowledge gained from development of the MERS vaccine, the team made a similar microneedle vaccine targeting the spike protein of SARS-CoV-2. The vaccine prompted robust antibody production in the mice within two weeks.

The vaccinated animals haven’t been tracked for enough time to see if the long-term immune response is equivalent to that observed with the MERS vaccines. The mice have also not yet been challenged with SARS-CoV-2 infection. However, the findings are promising in light of results from the similar MERS vaccine.

The components of the experimental vaccine could be made quickly and at large-scale, the researchers say. The final product also doesn’t require refrigeration, so it could be produced and placed in storage until needed. The team has now begun the process of obtaining approval from the U.S. Food and Drug Administration to launch a phase 1 trial within the next several months.

Much work still needs to be done to explore the safety and efficacy of this candidate vaccine. “Testing in patients would typically require at least a year and probably longer,” Falo says. “This particular situation is different from anything we’ve ever seen, so we don’t know how long the clinical development process will take.”