Expert warns against depending on face shield for COVID-19 prevention.

A molecular biology expert has warned Nigerians against depending on only face shield as protection against the novel coronavirus when they go out.

Speaking on a live television programme, Dr. Christian Happi, a professor of molecular biology and genomics and director of the African Centre of Excellence for Genomics of Infectious Diseases at Redeemer’s University, explained that a face shield does not give the same level of protection against COVID-19 as a face mask.

“What’s the basis for wearing a face shield without a face mask? I wonder if the shield can prevent the viral particle in the air that you are breathing. I think just wearing a shield without a face mask is lopsided.

 “Of course, the face shield can be added as an additional measure to mask. Other than that, wearing a shield alone is not helpful,” he said.

According to Tony Blair Institute for Global Change, the plastic face visors may provide full-face protection but there are some misconceptions about how they work.

“Face shields are arguably best at protecting from coughs and sneezes. Studies have shown, however, that viral droplets, particularly small airborne speech particles, can remain in the air for some time and these particles can be sucked in around the shield.

“Shields can, therefore, be very useful tools for those facing regular contact, at proximity, with others – for instance in medical settings. They also have great value in professions where non-verbal communication through facial expressions is important, such as teaching. They could be valuable in giving protection and confidence to teachers, enabling them to return to a classroom environment,” it said.

The institute further emphasised that unlike face shields, which are designed to protect the wearer, face masks inhibit the outward transmission of viral particles and therefore help protect others.

“For the general public, a normal medical mask is likely to be more effective, therefore, in helping control transmission of the virus,” the institute said.


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