Apple now requires retail and corporate employees to provide proof of a COVID-19 booster shot, said the Verge’s report.

All of the employees who haven’t proof of booster shot or are unvaccinated will need negative COVID-19 tests. The new rule will come into effect on January 24.

It was not immediately clear if the testing requirement applies to both corporate and retail employees. The memo read, according to The Verge said:

“Due to waning efficacy of the primary series of COVID-19 vaccines and the emergence of highly transmissible variants such as Omicron, a booster shot is now part of staying up to date with your COVID-19 vaccination to protect against severe disease.”

Many companies such as Meta and Alphabet Inc‘s Google, have been strengthening their COVID-19 rules, mandating vaccination and delaying back-to-office plans as the Omicron variant increases infections across the country.