Efficacy and feasibility of a novel semi-facial respirator with chitosan nanoparticles on the incidence of SARS-CoV-2 infection in healthcare professionals: randomized controlled trial

Summary

In 230 Brazilian hospital workers, a chitosan-nanoparticle respirator was compared with a conventional N95. Infection rates did not differ for COVID-19 (adjusted odds ratio 1.08, wide interval 0.21 to 5.47) or influenza, and comfort was rated high in both groups.

Key points

• COVID-19 incidence did not differ between the chitosan-nanoparticle respirator and a standard N95 (adjusted odds ratio 1.08, 95% confidence interval 0.21 to 5.47).
• Influenza incidence also did not differ (adjusted odds ratio 1.11, 95% confidence interval 0.17 to 7.01).
• Both respirators were rated excellent for usability and comfort.
• Design: blinded randomized trial in 230 health care workers at a large public hospital, March 2021 to June 2023; it compared two respirators, not a respirator against none.
• Funding: Brazilian public research funders (FAPDF, CNPq, UnB) and online crowdfunding.