Delta variant has shifted the war on the viral pandemic reopening the use and debate on face masks. On July 30th, United States saw a single day infection increase of 103,366 cases, highest daily increase since February 2021, which is attributed to the high transmissible Delta variant.
Recent information from the United States’ Centers for Disease Control and Prevention (CDC) indicates that in rare situations, fully vaccinated people get infected with Delta variant, which may not be severe to the infected. However, because of the number of viral loads in infected people in nasal pharynx and throat, they can be carriers and can infect others—particularly unvaccinated people.
It is clear from the recent findings that the coronavirus is airborne and hence apart from vaccines, non-medical countermeasures like face masks are life savers.
On July 27, 2021, CDC has recommended the use of face masks in indoor public spaces where Delta variant surge is high and breakthrough infections are emerging. CDC has also recommended the use of face masks in schools in the United States as the new school season begins soon. Face masks that have filtering ability, provide tight fit and give good form or comfort will find applications as barrier materials to counter infections.
Ongoing research on cotton and blends-based face coverings in the Nonwovens & Advanced Materials Laboratory at Texas Tech University has found that surgical 3-ply surgical face masks can have 60-80 % filtration capability of fine particles ranging from 30 nm to 150 nm, which is normally the size range of corona virus.
While N95 filters are the gold standard, continuous usage of them may not be possible due to comfort issue. In speaking to this scribe, an internal medicine expert from Toronto, Canada stated that N95 masks can be worn continuously for a period up to 60 minutes. In isolation wards where acute COVID-19 patients are treated, such N95 masks, medical gowns and other precautions are necessary.
Surgical masks and enhanced face covers can provide some barrier efficiency against virus and are highly recommended in areas where there are high and substantial infections due to Delta variant. Public must be informed about different face masks and their filtration and protection capabilities to make informed judgement.
By Seshadri Ramkumar,
Professor, Texas Tech University, USA
