Potential COVID-19 nasal spray vaccine shows promise in mice

Reviewed by Emily Henderson, B.Sc.Nov 15 2021

A single sniff may one day be all it takes to immunize yourself against COVID-19.

Ramasamy Paulmurugan, PhD, and Tarik Massoud, MD, PhD, both professors of radiology, are leading an effort to stop the coronavirus at its most frequent point of entry: the nose.

The gold standard for vaccination is through an intramuscular shot to the arm. But that's really a roundabout way to achieve a barrier against a respiratory virus. We thought, theoretically, that administering protection at the site of infection could produce a more robust response."

Tarik Massoud, MD, PhD, professor of radiology

So far, the team's aerosolized vaccine has been delivered only in the snouts of mice, but it's shown promise in protecting against a pseudovirus that closely resembles SARS-CoV-2.

Powering the intranasal spray's protection are gold nanoparticles carrying bits of harmless, virus-mimicking DNA that trigger a generation of antibodies — protective soldiers of the immune system — and other immune cells that remember the invader so they can quickly spot and neutralize the threat.

In addition to conjuring robust immunity, the molecules generated by the spray act as a physical blockade against viral infection, limiting the amount of virus that can settle into the nasal passages and travel into the lungs, potentially reducing transmission to others.

The goal, said Paulmurugan, is to create a stable, long-lasting intranasal COVID-19 vaccine that can be shipped globally and self-administered — no medical workers required. Although the initial results are exciting, he said, it's too soon for the public to think about swapping a shot for a spray. But he and Massoud are optimistic that a human trial may be on the not-too-distant horizon.

A paper describing the study published in ACS Nano Oct. 27. Paulmurugan and Massoud are co-senior authors. Postdoctoral scholar Uday Kumar, PhD, is the lead author.