A multi-month survey recently revealed how little employers initially understood about the pandemic—and how agile and creative they quickly became to keep their workers safe and productive.

Since April, global professional services firm Mercer has conducted a series of surveys called Leading through the Pandemic, which asked employers about their perceptions of the health crisis and actions they’ve taken to protect their workers and company. Collectively, more than 3,000 employers responded.

In the beginning, employers believed the pandemic was going to be a short-term business disruption, says Kate Brown, leader of the Center of Health Innovation at Mercer. “As we continued to survey employers … it became clear that they have changed the way they’re thinking about it—that this limited business disruption is really a much bigger, longer-term event that will have ripple effects on their strategy and business for years to come.”

Before the pandemic, only 45% of the employers responding to Mercer’s 2020 Global Talent Trends Study believed that their workforce would be able to adapt to remote working and a new, more flexible style of work. But in April, their attitudes flipped: Nine out of 10 were offering flexible, work-from-home arrangements.

Earlier in the year, employers also anticipated a rise in healthcare claims costs and explored cost-cutting measures to help offset business losses. Instead, healthcare claims have since dropped by 40%.

Brown explains that many workers sheltered in place and didn’t seek preventive care. But trouble may lie ahead. Consider an employee who skips an annual mammogram, only to find out months later that she has advanced breast cancer.

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“What’s the downstream impact going to be from a healthcare-cost perspective?” Brown says. “We don’t know. Employers could hypothetically have more sick people on their plan at a later date because people didn’t seek preventive care in 2020.”

Employer attitudes toward leave also shifted.

Back in April, 19% of respondents believed their emergency leave policy would be sufficient for employees who contracted the virus while 21% didn’t think any emergency plan was needed. But by July, it was a different story. Only 22% required employees to use vacation or paid time off to quarantine. Fifteen percent offered paid leave for one quarantine, 21% for multiple quarantines and 10% for unlimited quarantines. Another 32% are considering revising their emergency leave policy for employees requiring multiple quarantines.

Related: COVID spotlights need for paid leave mandates

In hindsight, Brown says, “it’s kind of laughable” how optimistic survey respondents were about returning employees to work within six to eight weeks.

HR professionals must avoid falling into the same trap as many did earlier this year, believing that the pandemic would have a short lifespan. Moving forward, she says, employees will continue to expect, maybe even demand, work flexibility and behavioral health services.

“At this point,” Brown says, “I don’t think there is any going back to normal.”