Evidence directly refutes the effectiveness of face shields alone, showing they allow respiratory droplets to escape around the visor and block only a negligible fraction of cough aerosols.
The claim states that face shields without masks are effective at preventing respiratory illness transmission. Retrieved papers [2] and [3] directly evaluate face shields and find them highly ineffective at containing aerosols, noting that droplets easily bypass the visor. There are no papers supporting the claim that face shields alone are effective.