Ontario Science Table’s report and review of the data on Covid-19 screening of LTC home staff states, “there is no available real-world evidence to support or refute the benefits of screen testing in preventing LTC home COVID-19 outbreaks”.

Medical Mythbusting Commentary for March 25, 2021

Source:
Harms of weekly COVID-19 testing in Ontario long-term care may outweigh benefits, science table says

Reference:
Routine Asymptomatic SARS-CoV-2 Screen Testing of Ontario Long-Term Care Staff After COVID-19 Vaccination