A team coordinated at the Universidade de São Paulo's São Carlos Institute of Physics has shown that high-frequency ultrasound, of the kind used in routine medical imaging, can eliminate SARS-CoV-2 and H1N1 influenza viruses without damaging human cells. The study, published in Scientific Reports with a companion theoretical paper in the Brazilian Journal of Physics, attributes the effect to acoustic resonance: sound waves at 3 to 20 megahertz set the viral envelope vibrating until it ruptures and the particle is inactivated.
The distinction from existing ultrasound sterilisation is important. Conventional approaches rely on cavitation at lower frequencies, a violent process that can destroy tissue. Acoustic resonance, by contrast, leaves the temperature and pH of the medium unchanged and spares the surrounding cells, raising the prospect of antiviral applications inside the body rather than only on surfaces.
Because the mechanism depends on the shape of the viral particle rather than its genome, the researchers argue that mutations should not confer resistance, a striking contrast with drugs and vaccines that variants can evade. Virologists and inflammation specialists from USP's Ribeirão Preto medical and pharmaceutical schools contributed to the work, in vitro tests against dengue, chikungunya and Zika are under way, and the authors are clear that clinical use remains distant. As physics-led routes to antiviral therapy go, however, few are as conceptually elegant.