• Meta Platforms and Microsoft reopened their U.S. offices to employees this week.
• California-based Apple and Meta had insisted employees get booster shots, but they have not proven popular with the state's residents.

Facebook parent Meta Platforms will stop insisting that employees have Covid booster shots in order to come to its facilities in the U.S., a spokesperson confirmed to CNBC on Friday.

Technology companies have begun the process of luring their workers back to their corporate campuses. Meta, as well as Microsoft, held broad U.S. office reopenings on Monday.

"We updated our requirements in early March to align with CDC guidance, and now Covid-19 boosters are no longer required for entry, though strongly recommended," the spokesperson wrote in an email. "The primary vaccination requirement (one or two-shot series) remains in place."

The about-face comes less than three months after the social network operator announced rules for a return to the office.

The Meta spokesperson did not provide an explanation for the change.

In California, where Meta has its headquarters, 71% of the population is fully vaccinated, while 35% has received a booster shot, according to New York Times data. Case counts have fallen since January, the newspaper's data shows.

Apple, also based in California's San Francisco Bay Area, requires employees to show proof they have received a booster shot, technology news website the Verge reported in January.

The U.S. Food and Drug Administration on Tuesday authorized a second Pfizer-BioNTech or Moderna booster shot for people who are 50 or older at least four months after receiving an initial booster.

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