Autumn brings school buses, falling leaves and — less idyllically — flu season. If you haven't yet thought about how to keep your workers healthy and flu-free, now's the time.

The Centers for Disease Control and Prevention (CDC) recommends a yearly flu vaccination for everyone older than six months (barring medical contraindications), ideally before the end of October. The 2017-18 flu season, according to the CDC, was a doozy: It featured high levels of outpatient clinic and ER visits and was the first flu season to be classified as having "high severity" across all age groups.

3 recommendations for a flu-free workforce

How can employers mitigate the impact of flu season? Steve Wojcik, VP of public policy at the National Business Group on Health, offered HR Dive three recommendations.

1. Offer flu shots at work.

This is convenient, and there's usually no cost to the employee. "Employees are generally very appreciative of employers who do this," Wojcik said. Plus, from the employer’s perspective, "the cost of vaccinations is minimal compared to other health care needs related to getting the flu."

2. Encourage employees and their families to get vaccinated.

"For a company, it really makes sense to offer flu shots and encourage vaccination — there is a positive ROI," Wojcik emphasized. In addition to reducing absenteeism and loss of productivity, he said that employees with the flu generally experience four additional days of reduced effectiveness — not to mention the risk of spreading the illness to other employees.

"Even if you’re young, in your 20s and 30s, getting the flu shot is a good thing," Wojcik said. "Flu can be a serious illness. People die every year from the flu." Wojcik noted that during the infamous influenza epidemic of 1917-18, many young and healthy people died because their immune systems overreacted to the virus; "sometimes this young, healthy population is the most vulnerable."

Additionally, older workers and those with chronic conditions like cardiovascular disease should first talk to their doctors and then get the flu shot, to reduce potential complications, Wojcik said.

3. Ask that employees who feel sick stay home.

"Review your telework policy and encourage employees to take advantage of it whether they are sick or not," said Wojcik. "If employees are working at home, they have less exposure to others who may be sick — particularly those in the early stages of illness who may not realize it yet."

Mandatory vaccinations remain risky

If it's a good idea for everyone to get vaccinated, is it a good idea for employers to make vaccinations mandatory?

Not so fast says attorney Nathaniel Glasser, a member of the firm in the Washington, D.C., office of Epstein Becker & Green, P.C. Glasser is co-leader of the firm’s Health Employment and Labor strategic industry group.

Mandatory workplace vaccination policies are relatively uncommon outside the healthcare field, he said. Instead, employers are taking steps to encourage and recommend that employees get vaccinated without actively mandating it, Glasser explained.

Employers that do mandate vaccinations "have to be prepared to address any request for accommodation from employees." For example, an employee might voice a religious objection, or might have a disability that prevents them from receiving the vaccine, he said. Glasser noted that there have been a number of enforcement actions by both the EEOC and the DOJ in the last few years along those lines.

Depending on the specific nature of the objection, he said, the employee might be willing to receive a different type of flu vaccination, such as a nasal spray. He also noted that disability accommodations for flu shots are becoming more rare because of the various vaccine formulations available; there are now versions that are safe for those with egg allergies, for example.

If vaccination is just not possible, the employer could instead allow the employee to wear a surgical mask, modify his or her duties duties, or allow the employee to work from home, said Glasser.

Employers set the tone

With last year's flu season costing employers an estimated $21 billion in lost productivity, experts say it's crucial that businesses work to lessen its effects. "Employers may choose to do nothing, or be proactive," said Glasser.

For a variety of reasons, a proactive stance — even one that stops short of mandatory vaccinations — is smart. The flu may be common, but that doesn't mean employers should become complacent. Businesses can set the tone, promoting employee action. Get the message out: "Flu is not benign," said Wojcik.