The cough or sneeze sends droplets to nearby hard surfaces, where they're known to last quite some time. Spray Away removes them and leaves a residual coating of crystals that will kill any future microbes that may land on that surface.
Spray Away D.O.A.

The reason is that hard surfaces in your environment will harbor microbes for up to several days. Therefore, there is a need to sanitize your environment to control the spread from these many surfaces.

For instance, the SARS-CoV-2 is very contagious. It is unique in that asymptomatic subjects may spread the virus. https://www.cdc.gov/mmwr/volumes/69/wr/mm6914e1.htm

It has been determined that SARS-CoV-2 is spread in multiple ways, most commonly by smaller particles from exhaled air, known as aerosols. The SARS-CoV-2 virus remained viable in aerosols for up to 3 hours. https://www.nejm.org/doi/full/10.1056/NEJMc2004973.

This report included that SARS-CoV-2 can be transmitted by residency on hard surfaces like door knobs and gas station pumps. Studies have shown the infective life of the SARS-CoV-2 virus on various objects and was more stable on plastic and stainless steel than on copper and cardboard. The viable virus was detected up to 72 hours after application on plastic surfaces. It was viable up to 48 hours on stainless steel. It had shorter life on cooper at 4 hours. On cardboard, no viable SARS-CoV-2 was measured after 24 hours. The estimated median half-life of SARS-CoV-2 was approximately 5.6 hours on stainless steel and 6.8 hours on plastic. The authors stated their results indicate that there are two means of transmission of SARS-CoV-2 transmission; aerosol and fomite.

The virus can remain viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed). Therefore, there is an immediate need to kill this virus on hard surfaces. Ideally one would have a prophylactic means to coat such to prevent the residence. That exists with Spray Away DOA. In addition, there must be a means to control the aerosol transmission. (Coating of air filters). Also the authors recommended using a face mask.

A similar study published in Lancet showed residual SARS-CoV-2 viability on hard surfaces. After three hours, the virus had disappeared from printing and tissue paper. It took two days for it to leave wood and cloth fabric. After four days, it was no longer detectable on glass or paper money. It lasted the longest, seven days, on stainless steel and plastic.

https://www.thelancet.com/journals/lanmic/article/PIIS2666-5247(20)30003-3/fulltext
https://www.thelancet.com/action/showPdf?pii=S2666-5247%2820%2930003-3