Vaccine mandates are set to get more common in the workplace. 

A majority of U.S. employers — 52% — are planning or considering requirements for a COVID-19 shot by the end of the year, according to a new survey by consultant Willis Towers Watson. That’s more than double the 21% of companies polled that currently have some form of mandate. 

The options vary, ranging from a strict order for all employees to limiting access to certain areas to inoculated workers. About 14% of respondents also said they are weighing a health-care surcharge for people who choose not to get the vaccine, while 1% are planning to impose one, according to the survey of 961 employers, conducted Aug. 18-25.

The U.S. regulatory approval of Pfizer Inc.’s shot last month has prompted a growing number of employers to adopt mandates as the highly contagious delta variant spreads. Goldman Sachs Group Inc., Walmart Inc., McDonald’s Corp. and Walt Disney Co. are among companies requiring at least some employees to get vaccinated before going to their workplaces.

“Companies have been doing a really good job of making it easy to be vaccinated,” said Jeff Levin-Scherz, managing director of health and benefits at Willis Towers Watson. “Employers are now thinking, ‘How can we make it difficult for people not to be vaccinated?’”

See also: Workers Support Grows for Harsher Vaccine Stances From Employers

As the strategy plays out, companies need to carefully design their incentives and penalties to ensure they don’t disproportionately affect lower-paid workers, who also tend to be women or people of color, such as by adding too much in health-care costs, Levin-Scherz said.

The outcomes may not be clear for some time. The survey showed that 26% of employers don’t expect a full return to the office until the first quarter of next year, while 39% said the delay likely will stretch until the second quarter.