Residual antimicrobial coating efficacy against SARS-CoV-2

Area of Science:

• Microbiology
• Materials Science
• Infectious Diseases

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a significant public health threat.
• Non-porous surfaces can act as reservoirs for viral transmission.
• Antimicrobial coatings and films are being developed to mitigate surface contamination.

Purpose of the Study:

• To evaluate the residual efficacy of commercial antimicrobial coatings and films against SARS-CoV-2 on non-porous surfaces.
• To identify specific formulations that effectively inactivate SARS-CoV-2.

Main Methods:

• Application of antimicrobial products to stainless steel and ABS plastic coupons.
• Inoculation of coupons with SARS-CoV-2 under a 5% soil load.
• Quantification of infectious SARS-CoV-2 using TCID50 assay after a 2-hour contact time.

Main Results:

• Efficacy varied significantly among tested products, with log10 reductions ranging from 0.25 to over 3.0.
• Products containing 3-(trihydroxysilyl) propyldimethyloctadecyl ammonium chloride (0.5%-1.3%) were most effective.
• Formulations with other quaternary ammonium compounds showed lower efficacy against SARS-CoV-2.

Conclusions:

• Residual antimicrobial products exhibit formulation-dependent efficacy against SARS-CoV-2.
• Several products demonstrated significant antiviral activity on both stainless steel and ABS plastic.
• Efficacy is not solely predictable by active ingredient or concentration, highlighting the importance of formulation.