Research from the Business Continuity Institute (BCI) found 57% of employers have either weak plans or no plans to deal with the swine flu pandemic.
The spread of swine flu is expected to worsen as children return to school over the next two weeks.
Ben Willmott, senior policy adviser at the CIPD, said: "There is a real danger senior management teams ignore the threat to their business posed by a second and more serious wave of swine flu after seeing the first wave subside much more quickly than anticipated.
"The media and public hysteria sparked by the initial stage of the pandemic has created a ‘cry wolf' effect where the temptation for business leaders is to ask what all the fuss was about and get on with the priority of competing and surviving in recession.
"In the event of school and childcare closures, increased parent-worker absences could have a significant impact and increase employee absence rates in some areas well above the Government estimate of pandemic-related staff absences of 12%.
"Employers should consider how they would plan to respond to a surge of requests by staff for time off to care for sick children or to look after children in the event of widespread school closures.
"There is also the danger that the virus could change and become more virulent leading to higher infection and absence rates than anticipated.
The CIPD advises the following:
- Provide cross training of staff in critical areas so employees have the skills to fill in for absent colleagues
- Consider remote working to prevent spread of infection
- Consider reducing human contact for those with key skills
- Consider increasing customer self-service options such as telephone and online transactions
- Keep on top of government advice and adapt plans to reflect changes
- Communicate plans with staff, customers and suppliers
- Follow public health agency advice on efficient ways to contain the virus
- Provide a safe workplace by implementing rules on health reporting, office and personal hygiene, protective equipment, social distancing and working hours